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Phenotypic Variance (phenotypic + variance)
Kinds of Phenotypic Variance Selected AbstractsTHE PHENOTYPIC VARIANCE WITHIN PLASTIC TRAITS UNDER MIGRATION-MUTATION-SELECTION BALANCEEVOLUTION, Issue 6 2006Xu-Sheng Zhang Abstract How phenotypic variances of quantitative traits are influenced by the heterogeneity in environment is an important problem in evolutionary biology. In this study, both genetic and environmental variances in a plastic trait under migration-mutation-stabilizing selection are investigated. For this, a linear reaction norm is used to approximate the mapping from genotype to phenotype, and a population of clonal inheritance is assumed to live in a habitat consisting of many patches in which environmental conditions vary among patches and generations. The life cycle is assumed to be selection-reproduction-mutation-migration. Analysis shows that phenotypic plasticity is adaptive if correlations between the optimal phenotype and environment have become established in both space and/or time, and it is thus possible to maintain environmental variance (VE) in the plastic trait. Under the special situation of no mutation but maximum migration such that separate patches form an effective single-site habitat, the genotype that maximizes the geometric mean fitness will come to fixation and thus genetic variance (VG) cannot be maintained. With mutation and/or restricted migration, VG can be maintained and it increases with mutation rate but decreases with migration rate; whereas VE is little affected by them. Temporal variation in environmental quality increases VG while its spatial variance decreases VG. Variation in environmental conditions may decrease the environmental variance in the plastic trait. [source] Variability and divergence in Pongamia pinnata (L.) Pierre germplasm , a candidate tree for biodieselGCB BIOENERGY, Issue 6 2009N. SUNIL Abstract Three explorations were undertaken in South East Coastal zone of India covering parts of Andhra Pradesh (AP) and Orissa states to collect Pongamia pinnata (L.) Pierre germplasm during March,June 2007. A total of 123 accessions were collected and seed data recorded were analyzed for morphometric traits viz., seed length, seed width, seed thickness, 100-seed weight and oil content. Variation in the collected germplasm was analyzed using anova, simple measures of variation and D2 statistics. Significant genetic variability between seed traits and oil content and association among the seed traits was recorded. Phenotypic variance was higher than genotypic variance for all the characters indicating dominant role of environment. High heritability (broad sense) for 100-seed weight (97.6%) and oil content (86.7%) indicated the reliability of these characters as selection criteria for plus trees. Genetic gain was maximum for 100-seed weight (62.6%) followed by oil content (30.5%). D2 analysis grouped the accessions into 12 clusters. Cluster XII and cluster IX were the most diverse based on the intercluster distance. Based on the observed diversity, Chittoor, Srikakulam and Adilabad districts of AP are most suitable for collecting diverse germplasm lines and also for in situ conservation. [source] Inclusive heritability: combining genetic and non-genetic information to study animal behavior and cultureOIKOS, Issue 2 2010Étienne Danchin Phenotypic variance results from variation in biological information possessed by individuals. Quantitative geneticists often strive to partition out all environmental variance to measure heritability. Behavioral biologists and ecologists however, require methods to integrate genetic and environmental components of inherited phenotypic variance in order to estimate the evolutionary potential of traits, which encompasses any form of information that is inherited. To help develop this integration, we build on the tools of quantitative genetics and offer the concept of ,inclusive heritability' which identifies and unifies the various mechanisms of information transmission across generations. A controversial component of non-genetic information is animal culture, which is the part of phenotypic variance inherited through social learning. Culture has the unique property of being transmitted horizontally and obliquely, as well as vertically. Accounting for cultural variation would allow us to examine a broader range of evolutionary mechanisms. Culture may, for instance, produce behavioral isolating mechanisms leading to speciation. To advance the study of animal culture, we offer a definition of culture that is rooted in quantitative genetics. We also offer four testable criteria to determine whether a trait is culturally inherited. These criteria may constitute a conceptual tool to study animal culture. We briefly discuss methods to partition out cultural variance. Several authors have recently called for ,modernizing the modern synthesis' by including non-genetic factors such as epigenetics and phenotypic plasticity in order to more fully explain phenotypic evolution. Here, we further propose to broaden the concept of inheritance by incorporating the cultural component of behavior. Applying the concept of inclusive heritability may advance the integration of multiple forms of inheritance into the study of evolution. [source] A geometric morphometric approach to the quantification of population variation in sub-Saharan African craniaAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 1 2010Daniel Franklin We report here on new data examining cranial variation in 18 modern human sub-Saharan African populations. Previously, we investigated variation within southern Africa; we now extend our analyses to include a series of Central, East, and West African crania, to further knowledge of the relationships between, and variation and regional morphological patterning in, those populations. The sample comprises 377 male individuals; the three-dimensional coordinates of 96 landmarks are analyzed using Procrustes-based methods. Interpopulation variation is examined by calculating shape distances between groups, which are compared using resampling statistics and parametric tests. Phenotypic variance, as a proxy for genetic variance, is measured and compared across populations. Principal components and cluster analyses are employed to explore relationships between the populations. Shape differences are visualized using three-dimensional rendered models. Observed disparity patterns imply a mix of differences and similarities across populations, with no apparent support for genetic bottlenecks, which is likely a consequence of migrations that may have influenced differences in cranial form; supporting data are found in recent molecular studies. The Pygmy sample had the most distinctive cranial morphology; characteristically small in size with marked prognathism. These features characterized, although less strongly, the neighboring Bateke, and are possibly related to similar selective pressures in conjunction with interbreeding. Small cranial size is also involved in the considerable distinctiveness of the San and Khoikhoi. The statistical procedures applied in this study afford a powerful and robust means of quantifying and visualizing the magnitude and pattern of cranial variation between sub-Saharan African populations. Am. J. Hum. Biol., 2010. © 2009 Wiley-Liss, Inc. [source] Nonlinear epigenetic variance: review and simulationsDEVELOPMENTAL SCIENCE, Issue 1 2010Kees-Jan Kan We present a review of empirical evidence that suggests that a substantial portion of phenotypic variance is due to nonlinear (epigenetic) processes during ontogenesis. The role of such processes as a source of phenotypic variance in human behaviour genetic studies is not fully appreciated. In addition to our review, we present simulation studies of nonlinear epigenetic variance using a computational model of neuronal network development. In each simulation study, time series for monozygotic and dizygotic twins were generated and analysed using conventional behaviour genetic modelling. In the results of these analyses, the nonlinear epigenetic variance was subsumed under the non-shared environmental component. As is commonly found in behaviour genetic studies, observed heritabilities and unique environmentabilities increased with time, whereas common environmentabilities decreased. The fact that the phenotypic effects of nonlinear epigenetic processes appear as unsystematic variance in conventional twin analyses complicates the identification and quantification of the ultimate genetic and environmental causes of individual differences. We believe that nonlinear dynamical system theories provide a challenging perspective on the development of individual differences, which may enrich behaviour genetic studies. [source] COMPARING STRENGTHS OF DIRECTIONAL SELECTION: HOW STRONG IS STRONG?EVOLUTION, Issue 10 2004Joe Hereford Abstract The fundamental equation in evolutionary quantitative genetics, the Lande equation, describes the response to directional selection as a product of the additive genetic variance and the selection gradient of trait value on relative fitness. Comparisons of both genetic variances and selection gradients across traits or populations require standardization, as both are scale dependent. The Lande equation can be standardized in two ways. Standardizing by the variance of the selected trait yields the response in units of standard deviation as the product of the heritability and the variance-standardized selection gradient. This standardization conflates selection and variation because the phenotypic variance is a function of the genetic variance. Alternatively, one can standardize the Lande equation using the trait mean, yielding the proportional response to selection as the product of the squared coefficient of additive genetic variance and the mean-standardized selection gradient. Mean-standardized selection gradients are particularly useful for summarizing the strength of selection because the mean-standardized gradient for fitness itself is one, a convenient benchmark for strong selection. We review published estimates of directional selection in natural populations using mean-standardized selection gradients. Only 38 published studies provided all the necessary information for calculation of mean-standardized gradients. The median absolute value of multivariate mean-standardized gradients shows that selection is on average 54% as strong as selection on fitness. Correcting for the upward bias introduced by taking absolute values lowers the median to 31%, still very strong selection. Such large estimates clearly cannot be representative of selection on all traits. Some possible sources of overestimation of the strength of selection include confounding environmental and genotypic effects on fitness, the use of fitness components as proxies for fitness, and biases in publication or choice of traits to study. [source] GENETIC VARIATION IN MALE EFFECTS ON FEMALE REPRODUCTION AND THE GENETIC COVARIANCE BETWEEN THE SEXESEVOLUTION, Issue 6 2003MARY ELLEN CZESAK Abstract., Males of many insect species increase the fecundity and/or egg size of their mates through the amount or composition of their nuptial gifts or ejaculate. The genetic bases of such male effects on fecundity or egg size are generally unknown, and thus their ability to evolve remains speculative. Likewise, the genetic relationship between male and female investment into reproduction in dioecious species, which is expected to be positive if effects on fecundity are controlled by at least some of the same genes in males and females, is also unknown. Males of the seed beetle Stator limbatus contribute large ejaculates to females during mating, and the amount of donated ejaculate is positively correlated with male body mass. Females mated to large males lay more eggs in their lifetime than females mated to small males. We describe an experiment in which we quantify genetic variation in the number of eggs sired by males (mated to a single female) and found that a significant proportion of the phenotypic variance in the number of eggs sired by males was explained by their genotype. Additionally, the number of eggs sired by a male was highly positively genetically correlated with his body mass. The between-sex genetic correlation, that is, the genetic correlation between the number of eggs sired by males and the number of eggs laid by females, was highly positive when eggs were laid on Acacia greggii seeds. This indicates that males that sire many eggs have sisters that lay many eggs. Thus, some of the genes that control male ejaculate size (or some other fecundity-enhancing factor) when expressed in males appear to control fecundity when expressed in females. We found no significant interaction between male and female genotype on fecundity. [source] THE EVOLUTION OF GENETIC CANALIZATION UNDER FLUCTUATING SELECTIONEVOLUTION, Issue 1 2000Tadeusz J. Kawecki Abstract., If the direction of selection changes from generation to generation, the ability to respond to selection is maladaptive: the response to selection in one generation leads to reduced fitness in the next. Because the response is determined by the amount of genetic variance expressed at the phenotypic level, rapidly fluctuating selection should favor modifier genes that reduce the phenotypic effect of alleles segregating at structural loci underlying the trait. Such reduction in phenotypic expression of genetic variation has been named "genetic canalization." I support this argument with a series of two- and multilocus models with alternating linear selection and Gaussian selection with fluctuating optimum. A canalizing modifier gene affects the fitness of its carriers in three ways: (1) it reduces the phenotypic consequences of genetic response to previous selection; (2) it reduces the genetic response to selection, which is manifested as linkage disequilibrium between the modifier and structural loci; and (3) it reduces the phenotypic variance. The first two effects reduce fitness under directional selection sustained for several generations, but improve fitness when the direction of selection has just been reversed. The net effect tends to favor a canalizing modifier under rapidly fluctuating selection regimes (period of eight generations or less). The third effect improves fitness of the modifier allele if the fitness function is convex and reduces it if the function is concave. Under fluctuating Gaussian selection, the population is more likely to experience the concave portion of the fitness function when selection is stronger. Therefore, only weak to moderately strong fluctuating Gaussian selection favors genetic canalization. This paper considerably broadens the conditions that favor genetic canalization, which so far has only been postulated to evolve under long-term stabilizing selection. [source] Chromosomal loci that influence oral nicotine consumption in C57BL/6J × C3H/HeJ F2 intercross miceGENES, BRAIN AND BEHAVIOR, Issue 5 2007X. C. Li Several studies have demonstrated that there are genetic influences on free-choice oral nicotine consumption in mice. In order to establish the genetic architecture that underlies individual differences in free-choice nicotine consumption, quantitative trait loci (QTL) mapping was used to identify chromosomal regions that influence free-choice nicotine consumption in male and female F2 mice derived from a cross between C57BL/6J and C3H/HeJ mice. These two mouse strains were chosen not only because they differ significantly for oral nicotine consumption, but also because they are at or near phenotypic extremes for all measures of nicotine sensitivity that have been reported. A four-bottle choice paradigm was used to assess nicotine consumption over an 8-day period. The four bottles contained water or water supplemented with 25, 50 or 100 ,g/ml of nicotine base. Using micrograms of nicotine consumed per milliliter of total fluid consumed per day as the nicotine consumption phenotype, four significant QTL were identified. The QTL with the largest LOD score was located on distal chromosome 1 (peak LOD score = 15.7). Other chromosomes with significant QTL include central chromosome 4 (peak LOD score = 4.1), proximal chromosome 7 (peak LOD score = 6.1) and distal chromosome 15 (peak LOD score = 4.8). These four QTL appear to be responsible for up to 62% of the phenotypic variance in oral nicotine consumption. [source] Heritability of plasma amyloid , in typical late-onset Alzheimer's disease pedigreesGENETIC EPIDEMIOLOGY, Issue 1 2001Nilufer Ertekin-Taner Abstract Plasma amyloid ,42 peptide (A,42) levels are significantly elevated in all genetic forms of early-onset Alzheimer's disease caused by familial Alzheimer's disease mutations or Down's syndrome. Moreover, recent studies have determined that both plasma A,42 and A,40 levels are significantly elevated in late-onset Alzheimer's disease (LOAD) patients, their cognitively normal first-degree relatives, and members of typical LOAD families when compared to appropriate controls. To determine the magnitude of the genetic component affecting plasma A, levels, we estimated the heritability of plasma A,42 and A,40 in 15 extended, multigenerational LOAD pedigrees, using a variance components method. Heritability estimates as high as 73 and 54% were found for plasma A,42 and A,40 levels, respectively. Inclusion of the ApoE ,4 dosage as a covariate was not found to have a significant effect on the heritability of these traits. These results suggest that genetic determinants other than ApoE account for a very substantial percentage of the phenotypic variance in plasma A, levels. The high heritability and the significant elevation of these traits in LOAD pedigrees suggest that at least some of the genetic determinants of plasma A, levels may lead to elevated A, and LOAD in these families. Thus, we suggest that plasma A, levels are quantitative traits that may be excellent surrogate markers for use in linkage analysis to identify loci that are important in typical LOAD. Genet. Epidemiol. 21:19,30, 2001. © 2001 Wiley-Liss, Inc. [source] Mapping QTL for porcine muscle fibre traits in a White Duroc × Erhualian F2 resource populationJOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 6 2009W.B. Li Summary Muscle fibre traits are related with meat quality in meat animals. In this study, a whole-genome scan with 183 microsatellite markers covering the pig genome was performed to identify quantitative trait loci (QTL) for cross-sectional area, numerical percentage and relative area of type I, IIA and IIB myofibres, fibre number per square centimetre and total fibre number in the longissimus muscle by using 120 F2 animals in a White Duroc × Erhualian intercross. In total, 20 QTL were mapped on pig chromosomes (SSC) 1, 2, 7, 8, 9, 11, 15, 16 and X, of which eight reached genome-wide significance levels and explained large proportions (6.53,34.63%) of phenotypic variance. Five QTL detected in this study confirmed the previous QTL reports and the others were detected for the first time. Chinese Erhualian alleles are generally associated with muscle fibre traits favourable for meat quality. [source] Genome-wide linkage and QTL mapping in porcine F2 families generated from Pietrain, Meishan and Wild Boar crossesJOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 6 2003H. Geldermann Summary Three informative pig F2 families based on European Wild Boar (W), Meishan (M) and Pietrain (P) crosses have been used for genome-wide linkage and quantitative trait loci (QTL) analysis. Altogether 129 microsatellites, 56 type I loci and 46 trait definitions (specific to growth, fattening, fat deposition, muscling, meat quality, stress resistance and body conformation) were included in the study. In the linkage maps of M × P, W × P and W × M families, average spacing of markers were 18.4, 19.7 and 18.8 cM, the numbers of informative meioses were 582, 534 and 625, and the total lengths of autosomes measured were 27.3, 26.0 and 26.2 Morgan units, respectively. Maternal maps were on average 1.3 times longer than paternal maps. QTLs contributing more than 3% of F2 phenotypic variance could be identified at p < 0.05 chromosome-wide level. Differences in the numbers and positions of QTLs were observed between families. Genome-wide significant QTL effects were mapped for growth and fattening traits on eight chromosomes (1, 2, 4, 13, 14, 17, 18 and X), for fat deposition traits on seven chromosomes (1, 2, 3, 4, 6, 7 and X), for muscling traits on 11 chromosomes (1, 2, 3, 4, 6, 7, 8, 12, 14, 15 and X), for meat quality and stress resistance traits on seven chromosomes (2, 3, 6, 13, 16, 18 and X), and QTLs for body-conformation traits were detected on 14 chromosomes. Closely correlated traits showed similar QTL profiles within families. Major QTL effects for meat quality and stress resistance traits were found on SSC6 in the interval RYR1-A1BG in the W × P and M × P families, and could be attributed to segregation of the RYR1 allele T derived from Pietrain, whereas no effect in the corresponding SSC6 interval was found in family W × M, where Wild Boar and Meishan both contributed the RYR1 allele C. QTL positions were mostly similar in two of the three families for body conformation traits and for growth, fattening, fat deposition and muscling traits, especially on SSC4 (interval SW1073-NGFB). QTLs with large effects were also mapped on SSC7 in the major histocompatibility complex (MHC) (interval CYP21A2-S0102) and affected body length, weight of head and many other traits. The identification of DNA variants in genes causative for the QTLs requires further fine mapping of QTL intervals and a positional cloning. However, for these subsequent steps, the genome-wide QTL mapping in F2 families represents an essential starting point and is therefore significant for animal breeding. Zusammenfassung Drei informative F2 -Familien, die aus Kreuzungen von Europäischem Wildschwein (W), Meishan (M) und Pietrain (P) erstellt worden waren, wurden für eine genomweite Kopplungs- und QTL-Analyse benutzt. Insgesamt wurden 129 Mikrosatellitenloci, 56 Type-I-Loci und 46 Merkmalsdefinitionen (für Wachstum, Mastleistung, Fettansatz, Bemuskelung, Fleischqualität, Stressresistenz und Körperform) in die Untersuchungen einbezogen. In den Kopplungskarten der Familien M × P, W × P und W × M wurden durchschnittliche Markerabstände von 18.4, 19.7 bzw. 18.8 cM erreicht und 582, 534 bzw. 625 informative Meiosen beobachtet. Für die Gesamtlängen der Autosomen wurden in den drei Familien 27.3, 26.0 bzw. 26.2 Morgan-Einheiten gemessen. Die maternalen Kopplungskarten waren durchschnittlich 1.3-fach länger als die paternalen. QTLs, die mehr als 3% der phänotypischen Varianz in der F2 -Generation erklärten, konnten mit p < 0.05 chromosomenweitem Signifikanzniveau nachgewiesen werden. Zwischen den Familien wurden Differenzen in den Anzahlen und Positionen der QTLs beobachtet. Genomweit signifikante QTL-Effekte wurden für Wachstum und Fettansatz auf acht Chromosomen (1, 2, 4, 13, 14, 17, 18 und X) kartiert, für Fettansatz auf sieben Chromosomen (1, 2, 3, 4, 6, 7 und X), für Bemuskelung auf elf Chromosomen (1, 2, 3, 4, 6, 7, 8, 12, 14, 15 und X), für Fleischqualität/Stressresistenz auf sieben Chromosomen (2, 3, 6, 13, 16, 18 und X), und QTLs für die Körperform wurden auf 14 Chromosomen kartiert. Eng korrelierte Merkmale zeigten ähnliche QTL-Profile innerhalb Familien. Die bedeutsamsten QTL-Effekte wurden für Fleischqualitäts- und Stressresistenzmerkmale auf Chromosom 6, Intervall RYR1-A1BG, in den Familien W × P und M × P gefunden, während in diesem Chromosomenintervall in der Familie W × M, in der der RYR1 -Locus keine segregierenden Exon-Allele aufwies, kein QTL zu erkennen war. Mehrere der QTL-Positionen waren für die Körperform wie auch für Wachstum, Mastleistung, Fettansatz und Bemuskelung in zwei von drei Familien ähnlich. Dies galt besonders für Chromosom 4 (Intervall SW1073-NGFB). QTLs mit großen Effekten wurden auf Chromosom 7 im MHC (Intervall CYP21A2-S0102) kartiert; sie beeinflussten Körperlänge, Kopfgewicht, aber auch viele weitere Merkmale. Zur Identifizierung der DNA-Varianten, die einem QTL zugrunde liegen, ist eine Feinkartierung von QTLs und positionale Klonierung erforderlich. Für diese nachfolgenden Untersuchungsmethoden ist jedoch die genomweite QTL-Kartierung in F2 -Familien ein entscheidender Ausgangspunkt; sie ist deshalb bedeutungsvoll für die Tierzüchtung. [source] Linkage and QTL mapping for Sus scrofa chromosome 1JOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 2003P. Beeckmann Summary Linkage maps of Sus scrofa chromosome 1 (SSC1) have been produced using 10 markers in three different F2 families based on crosses of Meishan (M), Pietrain (P) and Wild Boar (W). The maps were similar for the different families and show higher paternal recombination, especially in the interval SW2130,SW803. Quantitative trait loci (QTLs) affecting body conformation, carcass composition, fat deposition and numbers of teats were identified in all three families. Major QTLs were mapped in chromosomal intervals centred at approximately 60, 120 and 170 cM. The QTLs explain up to 8.4% of phenotypic variance in the F2 generation. Pietrain QTL alleles were superior in comparison with Wild Boar and Meishan alleles for most of the trait values. Meishan alleles were associated with highest fat deposition. Additive gene effects were generally larger than dominance effects. QTL profiles on SSC1 differed between families, with the W × P family being most distinct. Zusammenfassung Kopplungskarten für Chromosom 1 (SSC1), die durch die Analyse von 10 Markern erstellt wurden, stimmten in drei untersuchten F2 -Familien (basierend auf Kreuzungen mit Meishan (M), Pietrain (P) und Wildschwein (W)) wie auch mit den bisher publizierten Karten überein. Die geschlechtsspezifischen Karten zeigten eine höhere Frequenz der Rekombinationen in der paternalen Meiose als in der maternalen, besonders im Intervall SW2130 bis SW803. Auf SSC1 konnten bedeutsame QTL-Effekte mit Wirkung auf Wachstum, Schlachtkörperzusammensetzung und Fettansatz sowie die Zitzenzahl in allen drei Familien kartiert werden, insbesondere in den Regionen um 60, 120 und 170 cM. Sie erklärten bis zu 8,4% der phänotypischen Varianz in der F2 -Generation. Pietrain-Allele zeigten positive Auswirkungen auf die meisten Fleischleistungsmerkmale. Meishan-Allele waren mit einer stärkeren Verfettung assoziiert. Es wurden Unterschiede zwischen den QTL-Profilen in den Familien beobachtet, wobei die Familie W × P besonders stark von den QTL-Profilen in den beiden anderen Familien abwich. [source] Linkage and QTL mapping for Sus scrofa chromosome 2JOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 2003S. S. Lee Summary Sus scrofa chromosome 2 (SSC2) linkage maps were generated from three F2 families involving Meishan (M), Pietrain (P) and Wild Boar (W) crosses and the same 10 marker loci. SSC2 linkage maps were similar between families and correspond to published maps. Quantitative trait loci (QTLs) for carcass traits, daily gain and heart weight were identified on SSC2, especially in the intervals 0,20 and 80,90 cM in the M × P family, the intervals 20,50 and 125,140 cM in the W × P family, and the interval 15,70 cM in the W × M family. QTL presence and position varied among families. QTL effects explained up to 10% of F2 phenotypic variance. Pietrain QTL alleles were associated with high muscle and heart mass, high daily gain and low fat deposition and Meishan alleles with high carcass fat content. Wild Boar alleles were associated with leaner carcass but lower daily gain than Meishan alleles. Zusammenfassung Kopplungskarten für Chromosom 2 (SSC2) wurden auf der Basis von drei F2 -Familien aus Kreuzungen von Wildschwein (W), Meishan (M) und Pietrain (P) mit Hilfe von zehn Markern erstellt. Sie zeigten eine gute Übereinstimmung zwischen den Familien und mit den bisher publizierten Karten. Auf SSC2 ließen sich QTLs mit Wirkung auf Schlachtkörperzusammensetzung, tägliche Zunahmen und Herzgewicht nachweisen. Die QTL-Positionen lagen in der Familie M × P in den Regionen 0 bis 20 cM und 80 bis 90 cM, in der Familie W × P in den Regionen 20 bis 50 cM und 125 bis 140 cM und in der Familie W × M in der Region 15 bis 70 cM. Die QTL-Effekte auf SSC2 erklärten bis zu 10% der phänotypischen Varianz in der F2 -Generation. An den QTL-Positionen zeigten Pietrain-Allele positive Auswirkungen auf die Fleischfülle, das Herzgewicht und die täglichen Zunahmen. Meishan-Allele waren mit einer stärkeren Verfettung assoziiert. Im Vergleich zu Meishan-Allelen traten die Wildschwein-Allele mit höherem Fleischanteil und geringeren täglichen Zunahmen auf. [source] Linkage and QTL mapping for Sus scrofa chromosome 11JOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 2003M. Dragos-Wendrich Summary Linkage and QTL maps of Sus scrofa chromosome 11 (SSC11) have been produced based on four microsatellite markers genotyped in three F2 families from Wild Boar (W), Meishan (M) and Pietrain (P) crosses. The maps were similar across the families and in agreement with already published maps. Quantitative Trait Loci (QTLs) were identified in the W × M family and not in the M × P and W × P families. The QTLs affected live weight, loin and neck meat weight, back-fat depth and food consumption, and explained up to 4.7% of the F2 phenotypic variance. Additive and dominance effects were similar in size. The Wild Boar QTL alleles led to higher trait values in comparison with Meishan alleles. Zusammenfassung Kopplungskarten für Chromosom 11 (SSC11), die durch Analyse von vier Mikrosatelliten-Markern in drei F2 -Familien aus Kreuzungen von Wildschwein (W), Meishan (M) und Pietrain (P) erstellt wurden, zeigten eine gute Übereinstimmung zwischen den Familien sowie mit Literaturergebnissen. Quantitative Trait Loci (QTLs) waren in der Familie W × M nachzuweisen, jedoch nicht in den Familien M × P und W × P. Sie beeinflussten Lebendgewicht, Kotelettstranggewicht, Rückenspeckdicke und Futteraufnahme und erklärten bis zu 4,7% der phänotypischen Varianz in der F2 -Generation. Additiv- und Dominanzeffekte waren ähnlich groß. Wildschwein-QTL-Allele führten im Vergleich zu Meishan-Allelen zu höheren Merkmalswerten. [source] Linkage and QTL mapping for Sus scrofa chromosome 12JOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 2003G. Yue Summary The SSC12 (Sus scrofa chromosome 12) linkage and QTL maps were generated using 11 markers, of which seven to 10 have been used in the three F2 families based on Wild Boar (W), Meishan (M) and Pietrain (P) crosses. Linkage maps showed identical marker order among the families, but differed in total lengths. They were in agreement with the already published maps, except for the order SWR1021,SW605. Most quantitative trait loci (QTLs) affected fat or meat content in carcass, but were also found for some other traits (heart weight, CK20 values and teat number). They explained up to 5.4% of F2 phenotypic variance. Meishan alleles had stimulating effects on fat deposition and decreasing effects on lean content and CK20 value. The QTL profiles differed between families, with QTL effects in the vicinity of the GH1 locus found solely in the M × P family. Zusammenfassung Auf der Basis von elf Markern wurden Kopplungs- und QTL-Karten für Chromosom 12 (SSC12) in drei F2 -Familien aus Kreuzungen von Wildschwein (W), Meishan (M) und Pietrain (P) erstellt. Hierbei wurden sieben bis zehn Marker pro F2 -Familie benutzt. Die Kopplungskarten zeigten eine gleichartige Anordnung der Loci für alle Familien, jedoch mit verschiedenen Kartenlängen. Sie stimmen, außer in der Anordnung SWR1021,SW605, mit bereits publizierten Karten überein. Quantitative Trait Loci (QTLs) waren hauptsächlich für Merkmale des Fett-oder Fleischanteils im Schlachtkörper festzustellen, daneben aber auch für weitere Merkmale (Herzgewicht, CK20 -Wert, Zitzenzahl). Sie erklärten bis zu 5,4% der phänotypischen Varianz in der F2 -Generation. Meishan-Allele waren assoziiert mit einer Steigerung des Fettansatzes sowie einer Reduktion der Anteile wertvoller Teilstücke und der CK20 -Werte. Die QTL-Profile unterschieden sich zwischen den Familien und ließen Assoziationen mit dem GH1 -Locus nur in der Familie M × P erkennen. [source] Estimation of genetic parameters for canine hip dysplasia in the Swiss Newfoundland populationJOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 3 2003E. Dietschi Summary Variance components and genetic parameters for hip dysplasia (HD) in a population of 1372 Newfoundlands were estimated using restricted maximum likelihood method applied to animal models comprising fixed effects of gender, screening expert and HD grading system. All models investigated included a random direct genetic effect, but differed for combinations of random maternal genetic effect, permanent maternal environmental effect and kennel effect. Although kennels had no effect on HD, the permanent maternal environmental effects, however were significant. The results for the maternal genetic effect were ambiguous. These results suggest a confounding of these three random effects. The model that included the fixed effects, the direct genetic effect and the permanent maternal environmental effect was the most parsimonious combined with an optimal fit. The heritability estimated with this model was 0.28 and the proportion of the permanent maternal environmental effect of the phenotypic variance was 0.10. The effects of gender and screening expert were significant but not the one of HD grading system. Zusammenfassung Schätzung genetischer Populationsparameter für die Hüftgelenksdysplasie bei den Neufundländern in der Schweiz In einer Hundepopulation von 1372 Neufundländern wurden für die Hüftgelenksdysplasie mit Hilfe der "restricted maximum likelihood method" Varianzkomponenten und genetische Parameter geschätzt, wobei ein Tiermodell zu Grunde gelegt wurde. Alle verwendeten Modelle enthielten einen zufälligen direkten genetischen Effekt und in unterschiedlichen Kombinationen einen zufälligen maternalen Effekt, einen zufälligen permanent maternalen Umwelteffekt und einen zufälligen Zwinger-Effekt. Als fixe Effekte wurden das Geschlecht, der Auswertungs-Experte und das HD-Einteilungssystem berücksichtigt. Der Zwinger hat keinen Einfluss auf die Hüftgelenksdysplasie, aber der permanent maternale Umwelteffekt ist signifikant. Der maternal genetische Effekt verhält sich je nach Modell unterschiedlich. Diese Resultate legen eine Vermengung dieser drei Effekte nahe. Die beste Anpassung an die Daten zeigt dasjenige Modell, das die fixen Effekte, den direkten genetischen Effekt und den permanent maternalen Umwelteffekt enthält. Die mit diesem Modell geschätzte Heritabilität beträgt 0,28 und der Anteil des permanent maternalen Umwelteffektes an der phänotypischen Varianz 0,10. Das Geschlecht und die Auswertungs-Experten sind signifikant, das HD-Einteilungssystem nicht. [source] Estimation of variance components due to imprinting effects with DFREML and VCE: results of a simulation studyJOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 1 2002A. ESSL Treating gametes as homozygous diploid individuals, TIER and SÖLKNER (Theor. Appl. Genet. 85: 868,872, 1993) proposed a method which manages the use of available computer programs with a common animal model to estimate variance components caused by imprinting effects. Despite some relevant model restrictions, this approach has already been used in some field data analyses by an adapted version of the widely used DFREML computer program, subsequently indicated by DFREMLa. The main objective of this study was to ascertain the properties of DFREMLa by computer simulation and to examine other alternative estimation approaches. The most important results may be summarized as follows: (1) Treating gametes as homozygous diploid individuals has the consequence that one-half of the actually realized gametic effect is totally abstracted in variance component estimation. Thus, an additional adjustment of the phenotypic variance calculated by DFREMLa is necessary to get correct values of estimated variance component ratios. (2) Adjusted DFREMLa estimates yielded correct results when animals were unselected and only maternal or paternal imprinting (not both simultaneously) occurred. (3) When the model did not adequately account for the additive genetic component within a maternal lineage, significant upward biases for the cytoplasmic component were observed. (4) The use of a simple dam and sire model with appropriate relationship matrices can be recommended when only the difference of maternal and paternal imprinting effects is of primary interest and the covariance between maternal halfsibs is not substantially increased by common environmental effects. (5) An adequate estimation of variance components for all possible imprinting situations requires the use of an animal model augmented by both maternal and paternal gametic effects. Unfortunately, a computer program on the basis of such a model does not yet exist. Schätzung von Varianzkomponenten für Imprintingeffekte mittels DFREML und VCE: Ergebnisse einer Simulationsstudie TIER and SÖLKNER (Theor. Appl. Genet. 85: 868,872, 1993) schlugen eine Methode zur Schätzung von imprintingbedingten Varianzkomponenten vor, die mit einem einfach zu adaptierenden Computerprogramm auf der Basis eines üblichen Tiermodells vorgenommen werden kann, indem sie Gameten wie homozygot diploide Individuen behandelten. Obwohl dieser Ansatz einige praxisrelevante Einschränkungen hat, wurde er bereits bei einigen Felddatenanalysen verwendet. Für diesen Zweck wurde eine entsprechend adaptierte Version des häufig verwendeten Computerprogrammes DFREML eingesetzt, die im folgenden mit DFREMLa bezeichnet wird. Das Ziel der vorliegen Untersuchung lag darin, die Eigenschaften von DFREMLa bei verschiedenen Imprintingsituationen zu überprüfen und weiters die Brauchbarkeit anderer möglicher Schätzansätze zu überprüfen. (1) Werden Gameten wie diploide homozygote Individuen aufgefaßt, dann geht bei der Schätzung von Varianzkomponenten mit DFREMLa eine Hälfte des tatsächlich wirksamen Gameteneffektes völlig verloren. Das heißt, die von DFREMLa ausgewiesenen Ergebnisse müssen nachträglich entsprechend adjustiert werden, um korrekte Schätzergebnisse für alle jene Quotienten von Varianzkomponenten zu erhalten, bei denen die gesamte phänotypische Varianz im Nenner steht. (2) Die adjustierten DFREMLa Schätzwerte lieferten in all jenen Fällen korrekte Ergebnisse, wo keine Selektion der Tiere erfolgte und entweder nur maternales oder paternales Imprinting (nicht beide gleichzeitig) auftrat. (3) Alle Modelle, bei denen die additiv genetische Komponente innerhalb einer Kuhfamilie keine adäquate Berücksichtigung fand, führten zu einer systematischen Überschätzung der zytoplasmatischen Varianzkomponente. (4) Ist nur jene Varianzkomponente von Interesse, die durch unterschiedlich starkes maternales bzw. paternales Imprinting erklärt werden kann, dann kann auch die Verwendung einfacher Vater-bzw. Muttermodelle empfohlen werden. Voraussetzung hierfür ist allerdings, daß die Kovarianz zwischen mütterlichen Halbgeschwistern durch keine gemeinsame Umwelt erhöht ist. (5) Eine für alle Imprintingsituationen problemadäquate Schätzung von Varianzkomponenten verlangt die Anwendung eines Tiermodelles, erweitert um beide imprintingbedingten Gameteneffekte. Leider fehlt gegenwärtig hierfür noch ein entsprechendes Computerprogramm. [source] Genetic characterization of wild and captive rhesus macaques in China*JOURNAL OF MEDICAL PRIMATOLOGY, Issue 2 2008J. Satkoski Abstract The genetic structures of wild and captive rhesus macaque populations within China were compared by analyzing the mtDNA sequences of 203 captive-bred Chinese rhesus macaques with 77 GenBank sequences from wild-caught animals trapped throughout China. The genotypes of 22 microsatellites of captive Chinese rhesus macaques were also compared with those of captive Indian animals. The Chinese population is significantly differentiated from the Indian population and is more heterogeneous. Thus, compared with Indian rhesus macaques the phenotypic variance of traits with high heritability will be inflated in Chinese animals. Our data suggest that the western Chinese provinces have more subdivided populations than the eastern and southern Chinese provinces. The southern Chinese populations are the least structured and might have been more recently established. Human-mediated interbreeding among captive Chinese populations has occurred, implying that Chinese breeding strategies can influence the interpretation of biomedical research in the USA. [source] Genetic Mapping of Magnaporthe grisea Avirulence Gene Corresponding to Leaf and Panicle Blast Resistant QTLs in Jao Hom Nin Rice CultivarJOURNAL OF PHYTOPATHOLOGY, Issue 6 2009Tanee Sreewongchai Abstract The avirulence characteristic of Magnaporthe grisea isolate TH16 corresponding to Jao Hom Nin (JHN) rice cultivar was studied by mapping population of 140 random ascospore progenies derived from the cross between B1-2 and TH16 isolates. Segregation analyses of the avirulence characteristic performing on JHN rice at the seedling and flowering stages were performed in this mapping population. We used the reference map of Guy11/2539 to choose microsatellite DNA markers for mapping the avirulence gene. The genetic map of this population was constructed from 39-microsatellite markers. The genetic map was spanned by covering seven chromosomes with an average distance of 11.9 cM per marker. In mapping population the distribution of pathogenic and non-pathogenic progenies on JHN rice were found to be fitted to 1 : 1 ratio for two of the rice stages, seedling and flowering stages. The Quantitative Trait Loci (QTL) analysis for avirulence genes corresponding to two rice stages were located at the same region on chromosome 2 between markers Pyms305 and Pyms435. The LOD score and percentage of phenotypic variance explained (PVE) on two rice stages were 5.01/16.69 and 6.73/20.26, respectively. These loci were designated as Avr-JHN(lb) and Avr-JHN(pb) corresponding to leaf and panicle blast characteristics. The findings of this study can be the initial step for positional cloning and identifying any function of avirulence genes corresponding to leaf and panicle blast characteristics. [source] A novel form of resistance in rice to the angiosperm parasite Striga hermonthicaNEW PHYTOLOGIST, Issue 1 2006A. L. Gurney Summary ,,The root hemiparasitic weed Striga hermonthica is a serious constraint to grain production of economically important cereals in sub-Saharan Africa. Breeding for parasite resistance in cereals is widely recognized as the most sustainable form of long-term control; however, advances have been limited owing to a lack of cereal germplasm demonstrating postattachment resistance to Striga. ,,Here, we identify a cultivar of rice (Nipponbare) that exhibits strong postattachment resistance to S. hermonthica; the parasite penetrates the host root cortex but does not form parasite,host xylem,xylem connections. ,,In order to identify the genomic regions contributing to this resistance, a mapping population of backcross inbred lines between the resistant (Nipponbare) and susceptible (Kasalath) parents were evaluated for resistance to S. hermonthica. ,,Composite interval mapping located seven putative quantitative trait loci (QTL) explaining 31% of the overall phenotypic variance; a second, independent, screen confirmed four of these QTL. Relative to the parental lines, allelic substitutions at these QTL altered the phenotype by at least 0.5 of a phenotypic standard deviation. Thus, they should be regarded as major genes and are likely to be useful in breeding programmes to enhance host resistance. [source] Inclusive heritability: combining genetic and non-genetic information to study animal behavior and cultureOIKOS, Issue 2 2010Étienne Danchin Phenotypic variance results from variation in biological information possessed by individuals. Quantitative geneticists often strive to partition out all environmental variance to measure heritability. Behavioral biologists and ecologists however, require methods to integrate genetic and environmental components of inherited phenotypic variance in order to estimate the evolutionary potential of traits, which encompasses any form of information that is inherited. To help develop this integration, we build on the tools of quantitative genetics and offer the concept of ,inclusive heritability' which identifies and unifies the various mechanisms of information transmission across generations. A controversial component of non-genetic information is animal culture, which is the part of phenotypic variance inherited through social learning. Culture has the unique property of being transmitted horizontally and obliquely, as well as vertically. Accounting for cultural variation would allow us to examine a broader range of evolutionary mechanisms. Culture may, for instance, produce behavioral isolating mechanisms leading to speciation. To advance the study of animal culture, we offer a definition of culture that is rooted in quantitative genetics. We also offer four testable criteria to determine whether a trait is culturally inherited. These criteria may constitute a conceptual tool to study animal culture. We briefly discuss methods to partition out cultural variance. Several authors have recently called for ,modernizing the modern synthesis' by including non-genetic factors such as epigenetics and phenotypic plasticity in order to more fully explain phenotypic evolution. Here, we further propose to broaden the concept of inheritance by incorporating the cultural component of behavior. Applying the concept of inclusive heritability may advance the integration of multiple forms of inheritance into the study of evolution. [source] Differential response of Amaranthus tuberculatus (Moq ex DC) JD Sauer to glyphosatePEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 10 2005Ian A Zelaya Abstract Midwest USA farmers have reported inconsistent control of Amaranthus tuberculatus (= rudis) (Moq ex DC) JD Sauer by glyphosate in glyphosate-resistant crops. The potential of selection for decreased A tuberculatus sensitivity to glyphosate was therefore investigated in a reportedly resistant Everly, IA population (P0,EV). Evaluation of six A tuberculatus populations from the Midwest USA estimated a seedling baseline sensitivity of 2.15 mM glyphosate. Based on these results, three generations of divergent recurrent selection were implemented on P0,EV to isolate resistant and susceptible populations. A seedling assay was developed to screen large amounts of seeds and thus expedite the selection process. Whole-plant and seedling rate responses of P0,EV and a known pristine A tuberculatus population from Paint Creek, OH (P0,WT) identified no significant difference in response to glyphosate; however, greater phenotypic variance was ostensibly evident in P0,EV. The first recurrent generation selected for resistance at 3.2 mM glyphosate (RS1,R) had a 5.9- and 1.7-fold resistance increase at the seedling and whole-plant levels, respectively, compared with the susceptible generation selected at 32 µM glyphosate. After three cycles of recurrent selection, 14.6-fold difference in resistance at the seedling level and 3.1-fold difference at the whole-plant level were observed when comparing the populations selected for resistance (RS3,R) and susceptibility (RS3,S). Overall, recurrent selection increased the frequency of resistant individuals and decreased the variability to glyphosate at the population level. Nevertheless, variability for glyphosate resistance was still evident in RS3,R. Results herein suggested that A tuberculatus is inherently variable to glyphosate and that selection decreased the sensitivity to glyphosate. We purport that evolved glyphosate resistance in A tuberculatus may require multiple cycles of selection under field conditions. Historic estimated use of glyphosate alludes to the evolution of tolerant weed populations. Copyright © 2005 Society of Chemical Industry [source] Foliar and tuber late blight resistance in a Solanum tuberosum breeding populationPLANT BREEDING, Issue 2 2010H. Mayton With 2 figures and 2 tables Abstract The purpose of this research was to identify the genetic basis of foliar and tuber resistance to Phytophthora infestans in a potato breeding population developed from a cross between two tetraploid Solanum tuberosum lines, NY121 and NY115. The parent with high foliar resistance, NY121, was highly susceptible to tuber blight. Foliar resistance was assessed in field trials, while tuber blight was assessed both in the field and in the laboratory. A quantitative trait locus (QTL) explaining ca. 50% of the phenotypic variance for foliar resistance was located on the lower arm of linkage group V, and was loosely associated with tuber blight resistance (significantly in one of two trials). This QTL was confirmed in a separate sample from the same population. Tuber blight detected via laboratory assays was not correlated with tuber blight incidence in the field. Most markers associated with tuber blight resistance were not associated with foliar resistance and most markers associated with foliar resistance were not associated with tuber blight resistance. [source] QTL analysis for the resistance to small brown planthopper (Laodelphax striatellus Fallén) in rice using backcross inbred linesPLANT BREEDING, Issue 1 2010C. X. Duan With 3 figures and 3 tables Abstract Small brown planthopper (SBPH) is a serious pest of rice (Oryza sativa L.) in China. An indica variety ,Kasalath' is highly resistant to SBPH. A mapping population consisting of 98 BC1F9 lines, derived from a backcross of ,Nipponbare'/,Kasalath'//,Nipponbare', was applied to detect quantitative trait loci (QTL) for resistance to SBPH. In the modified seedbox screening test, three QTLs for SBPH resistance were mapped on chromosomes 3 and 11, explaining 49.9% of the phenotypic variance. In the antixenosis test, a total of three QTLs conferring antixenosis against SBPH were detected on chromosomes 3, 8 and 11, which accounted for 36.4% of the total phenotypic variance. In addition, two QTLs expressing antibiosis to SBPH were detected on chromosomes 2 and 11, explaining 13.8% and 14.7% of the phenotypic variance, respectively. Qsbph11e, Qsbph11f and Qsbph11g were located in the region between S2260 and G257 on chromosome 11, indicating that the locus is significant in conferring resistance to SBPH in ,Kasalath'. The molecular markers linked to these QTLs should be useful in the development of varieties with horizontal resistance to SBPH. [source] Development of molecular markers for crown rot resistance in wheat: mapping of QTLs for seedling resistance in a ,2-49' × ,Janz' populationPLANT BREEDING, Issue 6 2005B. C. Y. Collard Abstract Crown rot, caused by Fusarium pseudograminearum, is an important disease of wheat in Australia and elsewhere. In order to identify molecular markers associated with partial seedling resistance to this disease, bulked segregant analysis and quantitative trait loci (QTL) mapping approaches were undertaken using a population of 145 doubled haploid lines constructed from ,2-49' (partially resistant) × ,Janz' (susceptible) parents. Phenotypic data indicated that the trait is quantitatively inherited. The largest QTLs were located on chromosomes 1D and 1A, and explained 21% and 9% of the phenotypic variance, respectively. Using the best markers associated with five QTLs identified by composite interval mapping, the combined effect of the QTLs explained 40.6% of the phenotypic variance. All resistance alleles were inherited from ,2-49' with the exception of a QTL on 2B, which was inherited from ,Janz'. A minor QTL on 4B was loosely linked (19.8 cM) to the Rht1 locus in repulsion. None of the QTLs identified in this study were located in the same region as resistance QTLs identified in other populations segregating for Fusarium head blight, caused by Fusarium graminearum. [source] Identification of QTLs affecting adaptive traits in Castanea sativa MillPLANT CELL & ENVIRONMENT, Issue 9 2004M CASASOLI ABSTRACT A QTL analysis for three different adaptive traits was performed in an F1 progeny of Castanea sativa Mill. The female and male parents originated from two Turkish chestnut populations adapted to a drought and humid environment, respectively. QTLs for bud flush, growth and carbon isotope discrimination were detected over a 3-year period. Bud set was also recorded in the last year of measurement. Thirty-five individual QTLs were detected for phenology, 28 for growth and 17 for carbon isotope discrimination, most of them explaining a low to moderate proportion of the total phenotypic variance. QTLs were distributed throughout the whole genome. Temporally stable QTLs were identified for all the traits analysed, with phenology showing the higher proportion of stable QTLs. Interesting phenotypic correlations and co-localizations among QTLs for different adaptive traits were observed, allowing the formulation of an hypothesis about the genetic adaptation of the female parent to drought. [source] Quantitative resistance to Plum pox virus in Prunus davidiana P1908 linked to components of the eukaryotic translation initiation complexPLANT PATHOLOGY, Issue 3 2009G. Marandel A complex, polygenic resistance to Plum pox virus (PPV) was previously described in a wild peach-related species, Prunus davidiana clone P1908. In the current study, an analysis of quantitative trait loci (QTL) was performed on an F2 population comprising 99 individuals obtained by selfing the F1 individual #40 of an interspecific cross between susceptible nectarine cv. Summergrand and the resistant P. davidiana clone P1908. Six QTL were identified using both parametric and non-parametric methods of detection, individually explaining 5,28% of the phenotypic variance. The total phenotypic variation explained ranged from 29 to 58%. Alignment of the genetic map of the F2 cross with the P. davidiana parent map showed consistency of QTL over generations, with three of the six QTL co-localizing at the 1-LOD interval and another one at the 2-LOD interval. Two of the QTL were mapped onto linkage group one, where resistance to PPV was previously mapped in apricot. Development and mapping of new microsatellite markers linked to candidate genes revealed a striking co-localization of three of the detected QTL with gene copies coding for eukaryotic translation initiation factors eIF4E and eIF(iso)4G. As co-localization of one QTL with candidate gene eIF(iso)4E was previously reported in the F1 population, the results reported here strongly reinforce the idea that components of the eukaryotic translation initiation complex are correlated with resistance to PPV in P. davidiana P1908. [source] Estimates of heritability for reproductive traits in captive rhesus macaque femalesAMERICAN JOURNAL OF PRIMATOLOGY, Issue 9 2010Christine Gagliardi Abstract Records from a colony of captive Indian rhesus macaques (Macaca mulatta) were used to estimate heritability for a number of reproductive traits. Records were based on a total of 7,816 births by 1,901 females from 1979 to 2007. Heritability was estimated with a linear animal model using a multiple trait derivative free REML set of programs. Because no male parents were identified, the numerator relationship matrix contained female kinships established over six generations. Reproductive traits included female age at the birth of the first, second and last infant, age at death, inter-birth intervals, number of infants born per female and infant survival. Heritability for each trait was estimated as the ratio of the additive genetic variance to phenotypic variance adjusted for significant fixed effects. Estimates of heritability for early reproduction ranged from 0.000±0.072 for birth interval after the first reproduction to 0.171±0.062 for age of female at the first infant. Higher estimates of heritability were found for female longevity [0.325±0.143] and for productivity of deceased females born before 1991 [0.221±0.138]. Heritability for infant survival ranged from 0.061±0.018 for survival from 30 days to 1 year to 0.290±0.050 for survival from birth to 30 days when adjusted to an underlying normal distribution. Eight of the 13 estimates of heritability for reproductive traits in this study were different from zero [P<0.05]. Generally, heritability estimates reported in this study for reproductive traits of captive rhesus macaque females are similar to those reported in the literature for free-ranging rhesus macaque females and for similar reproductive traits of other species. These estimates of heritability for reproductive traits appear to be among the first for a relatively large colony of captive rhesus macaque females. Am. J. Primatol. 72:811,819, 2010. © 2010 Wiley-Liss, Inc. [source] QTL for body weight, morphometric traits and stress response in European sea bass Dicentrarchus labraxANIMAL GENETICS, Issue 4 2010C. Massault Summary Natural mating and mass spawning in the European sea bass (Dicentrarchus labrax L., Moronidae, Teleostei) complicate genetic studies and the implementation of selective breeding schemes. We utilized a two-step experimental design for detecting QTL in mass-spawning species: 2122 offspring from natural mating between 57 parents (22 males, 34 females and one missing) phenotyped for body weight, eight morphometric traits and cortisol levels, had been previously assigned to parents based on genotypes of 31 DNA microsatellite markers. Five large full-sib families (five sires and two dams) were selected from the offspring (570 animals), which were genotyped with 67 additional markers. A new genetic map was compiled, specific to our population, but based on the previously published map. QTL mapping was performed with two methods: half-sib regression analysis (paternal and maternal) and variance component analysis accounting for all family relationships. Two significant QTL were found for body weight on linkage group 4 and 6, six significant QTL for morphometric traits on linkage groups 1B, 4, 6, 7, 15 and 23 and three suggestive QTL for stress response on linkage groups 3, 14 and 23. The QTL explained between 8% and 38% of phenotypic variance. The results are the first step towards identifying genes involved in economically important traits like body weight and stress response in European sea bass. [source] | ||||||||||||||||||||||||||||