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Commercial Lines (commercial + line)
Selected AbstractsExpression of CP4 EPSPS in microspores and tapetum cells of cotton (Gossypium hirsutum) is critical for male reproductive development in response to late-stage glyphosate applicationsPLANT BIOTECHNOLOGY JOURNAL, Issue 5 2006Yun-Chia Sophia Chen Summary Plants expressing Agrobacterium sp. strain CP4 5-enolpyruvylshikimate-3-phosphate synthase (CP4 EPSPS) are known to be resistant to glyphosate, a potent herbicide that inhibits the activity of the endogenous plant EPSPS. The RR1445 transgenic cotton line (current commercial line for Roundup Ready® Cotton) was generated using the figwort mosaic virus (FMV) 35S promoter to drive the expression of the CP4 EPSPS gene, and has excellent vegetative tolerance to glyphosate. However, with high glyphosate application rates at developmental stages later than the four-leaf stage (late-stage applications: applications that are inconsistent with the Roundup® labels), RR1445 shows male sterility. Another transgenic cotton line, RR60, was generated using the FMV 35S promoter and the Arabidopsis elongation factor-1, promoter (AtEF1,) for the expression of CP4 EPSPS. RR60 has excellent vegetative and reproductive tolerance to applications of glyphosate at all developmental stages. Histochemical analyses were conducted to examine the male reproductive development at the cellular level of these cotton lines in response to glyphosate applications, and to investigate the correlation between glyphosate injury and the expression of CP4 EPSPS in male reproductive tissues. The expression of CP4 EPSPS in RR60 was found to be strong in all male reproductive cell types. Conversely, CP4 EPSPS expression in RR1445 was low in pollen mother cells, male gametophytes and tapetum, three crucial male reproductive cell types. Our results indicate that the FMV 35S promoter, although expressing strongly in most vegetative tissues in plants, has extremely low activity in these cell types. [source] Polymorphism of the pig acetyl-coenzyme A carboxylase , gene is associated with fatty acid composition in a Duroc commercial lineANIMAL GENETICS, Issue 4 2009D. Gallardo Summary Acetyl-coenzyme A carboxylase , (ACACA) catalyses the first committed step in the biosynthesis of long-chain fatty acids (FA) by converting acetyl-CoA into malonyl-CoA. In pigs, the ACACA gene maps to a chromosome 12 QTL with important effects on FA composition. In the present study, we have sequenced the coding region of the pig ACACA gene in 15 pigs, identifying 21 polymorphic sites that were either synonymous or non-coding. Ten of these SNPs segregated in a Duroc commercial population (n = 350) for which lipid metabolism and meat and carcass quality trait records were available. Significant associations were found between two linked single nucleotide polymorphisms (c.4899G>A and c.5196T>C) and percentages of carcass lean, intramuscular fat, monounsaturated, saturated (myristic, palmitic and stearic) and polyunsaturated (linoleic) FAs in the longissimus thoracis et lumborum muscle, along with serum HDL-cholesterol concentration. The most important allele substitution effects were observed for the polyunsaturated/saturated FA ratio (13,21% of the phenotypic mean) as well as for the percentages of ,-6 and polyunsaturated FAs, especially linoleic acid (7,16% of the phenotypic mean). These results suggest the existence of a causal mutation, mapping to the chromosomal region containing the pig ACACA gene, with marked effects on FA composition of meat. [source] The cholecystokinin type A receptor g.179A>G polymorphism affects feeding rateANIMAL GENETICS, Issue 2 2008R. D. Houston Summary A polymorphism within the 5, untranslated region of the cholecystokinin type A receptor (CCKAR) gene has been shown to affect feed intake and growth in commercial pig lines. To further investigate the phenotype of animals carrying alternative alleles at this polymorphism, we genotyped animals from a distinct segregating commercial line and an experimental cross F2 population, both with electronically recorded feeding pattern data. The data indicate that the daily feed intake increasing effect of the DQ496228:g.179G allele is mediated through a faster rate of feed intake, without evidence for an effect on other feeding behaviour traits. [source] Microsatellite markers associated with quantitative trait loci controlling antibody response to Escherichia coli and Salmonella enteritidis in young broilersANIMAL GENETICS, Issue 6 2002R. Yunis A unique resource population was produced to facilitate detection of microsatellite markers associated with quantitative trait loci controlling antibody (Ab) response in broiler chickens. Three F1 males were produced by mating two lines divergently selected on Ab response to Escherichia coli vaccination. Each F1 male was mated with females from four genetic backgrounds: F1, high-Ab line (HH), low-Ab line and commercial line, producing three resource families, each with four progeny types. About 1700 chicks were immunized with E. coli and Salmonella enteritidis vaccines. Selective genotyping was conducted on the individuals with highest or lowest average Ab to E. coli and S. enteritidis within each progeny type in each sire family. Twelve markers were significantly associated with Ab to E. coli and six of them were also associated with Ab to S. enteritidis, mostly exhibiting a similar low effect (, 0.35 phenotypic SD) in all progeny types. Four markers exhibited a highly significant and much larger effect (,1.7 SD), but only in progeny of females from the HH, suggesting that a backcross to the high parental line should be preferred over the commonly used F2 population. Results from two markers suggested a quantitative trait locus on chromosome 2 around 400 cM. The marker MCW0083, significant in two sire families, is closely linked to the bone morphogenetic protein 2 (BMP2) gene, known to be associated with the control of T-cell transformation in humans. [source] QTL for resistance to Salmonella carrier state confirmed in both experimental and commercial chicken linesANIMAL GENETICS, Issue 5 2009F. Calenge Summary The ability of chickens to carry Salmonella without displaying disease symptoms is responsible for Salmonella propagation in poultry stocks and for subsequent human contamination through the consumption of contaminated eggs or meat. The selection of animals more resistant to carrier state might be a way to decrease the propagation of Salmonella in poultry stocks and its transmission to humans. Five QTL controlling variation for resistance to carrier state in a chicken F2 progeny derived from the White Leghorn inbred lines N and 61 had been previously identified using a selective genotyping approach. Here, a second analysis on the whole progeny was performed, which led to the confirmation of two QTL on chromosomes 2 and 16. To assess the utility of these genomic regions for selection in commercial lines, we tested them together with other QTL identified in an [N×61] × N backcross progeny and with the candidate genes SLC11A1 and TLR4. We used a commercial line divergently selected for either low or high carrier-state resistance both in young chicks and in adult hens. In divergent chick lines, one QTL on chromosome 1 and one in the SLC11A1 region were significantly associated with carrier-state resistance variations; in divergent adult lines, one QTL located in the major histocompatibility complex on chromosome 16 and one in the SLC11A1 region were involved in these variations. Genetic studies conducted on experimental lines can therefore be of potential interest for marker-assisted selection in commercial lines. [source] Genetic diversity of Hungarian indigenous chicken breeds based on microsatellite markersANIMAL GENETICS, Issue 4 2009N. Bodzsar Summary Six local chicken breeds are registered in Hungary and are regarded as Hungarian national treasures: Hungarian White, Yellow and Speckled, and Transylvanian Naked Neck White, Black and Speckled. Three Hungarian academic institutes have maintained these genetic resources for more than 30 years. The Hungarian Yellow, the Hungarian Speckled and the Transylvanian Naked Neck Speckled breeds were kept as duplicates in two separate subpopulations since time of formation of conservation flocks at different institutes. In this study, we investigated genetic diversity of these nine Hungarian chicken populations using 29 microsatellite markers. We assessed degree of polymorphism and relationships within and between Hungarian breeds on the basis of molecular markers, and compared the Hungarian chicken populations with commercial lines and European local breeds. In total, 168 alleles were observed in the nine Hungarian populations. The FST estimate indicated that about 22% of the total variation originated from variation between the Hungarian breeds. Clustering using structure software showed clear separation between the Hungarian populations. The most frequent solutions were found at K = 5 and K = 6, respectively, classifying the Transylvanian Naked Neck breeds as a separate group of populations. To identify genetic resources unique to Hungary, marker estimated kinships were estimated and a safe set analysis was performed. We show that the contribution of all Hungarian breeds together to the total diversity of a given set of populations was lower when added to the commercial lines than when added to the European set of breeds. [source] Variation in neighbouring genes of the dopaminergic and serotonergic systems affects feather pecking behaviour of laying hensANIMAL GENETICS, Issue 2 2009K. Flisikowski Summary Feather pecking is a behavioural disorder of laying hens and has serious animal welfare and economic implications. One of the several aetiological hypotheses proposes that the disorder results from redirected exploratory behaviour. Variation in the gene encoding the dopamine D4 receptor (DRD4) has been shown to be associated with exploratory behaviour in several species, including in a passerine bird species. We therefore considered DRD4 as a candidate gene for feather pecking. We have annotated DRD4 in the chicken genome and have re-sequenced it in 140 animals belonging to: experimental layer lines divergently selected for high and low propensity to feather pecking; the unselected founder population; and two commercial lines with low and high propensity to feather pecking. We have identified two sub-haplotypes of DRD4 that are highly significantly associated with feather pecking behaviour in the experimental (P = 7.30 × 10,7) as well as in the commercial lines (P = 2.78 × 10,6). Linkage disequilibrium (LD) extends into a neighbouring gene encoding deformed epidermal autoregulatory factor 1 (DEAF1). The product of DEAF1 regulates the transcription of the gene encoding the serotonin (5-hydroxytryptamine) 1A receptor. Thus, DEAF1 represents another candidate gene for feather pecking. Re-sequencing of five animals homozygous for the ,low-pecking' sub-haplotype and of six animals homozygous for the ,high-pecking' sub-haplotype delineated an LD block of 14 833 bases spanning the two genes. None of the variants in the LD block is obviously functional. However, the haplotype information will be useful to select against the propensity to feather pecking in chicken and to elucidate the functional implications of the variants. [source] Expression of the porcine adrenergic receptor beta 2 gene in longissimus dorsi muscle is affected by cis -regulatory DNA variationANIMAL GENETICS, Issue 1 2009E. Muráni Summary The beta-2 adrenergic receptor (AR) mediates metabolic actions of catecholamines, including glycogenolysis, lipolysis and proteolysis, in muscle and adipose tissue. Factors influencing the density of beta-2 ARs thus might affect carcass composition and meat quality. One such factor might represent cis -regulatory DNA variation affecting mRNA expression of the adrenergic receptor beta 2 (ADRB2) gene in relevant tissues. To identify potential cis -regulatory DNA variation of porcine ADRB2, we comparatively sequenced part of the 5, flanking region and identified 10 single nucleotide polymorphisms (SNPs). The SNP at position g.673C>T (AF000134) resides in an evolutionarily conserved region (ECR) in an in silico predicted androgen response element. Quantification of total transcript levels and allelic expression imbalance (AEI) revealed significant variability in mRNA expression of ADRB2 in longissimus dorsi muscle of slaughter pigs, partly attributable to cis -regulatory DNA variation. However, the g.673C>T SNP has, in the given temporo-spatial context, no significant effect but is apparently in linkage disequilibrium with the causal cis -regulatory DNA variant. We used the g.673C>T SNP as a marker to study the association of ADRB2 variation with carcass and meat quality in four commercial lines. We found association with the pH of loin at 45 min and 24 h postmortem (p.m.) and with the pH of ham at 24 h p.m. Supporting evidence for ADRB2 as a candidate gene for pork quality is provided by our assignment of the gene to the telomeric end of the q arm of porcine chromosome 2, where several quantitative trait loci for meat quality were reported. [source] Quantitative trait loci associated with AutoFOM grading characteristics, carcass cuts and chemical body composition during growth of Sus scrofaANIMAL GENETICS, Issue 5 2006M. Mohrmann Summary A three-generation full-sib resource family was constructed by crossing two commercial pig lines. Genotypes for 37 molecular markers covering chromosomes SSC1, SSC6, SSC7 and SSC13 were obtained for 315 F2 animals of 49 families and their parents and grandparents. Phenotypic records of traits including carcass characteristics measured by the AutoFOM grading system, dissected carcass cuts and meat quality characteristics were recorded at 140 kg slaughter weight. Furthermore, phenotypic records on live animals were obtained for chemical composition of the empty body, protein and lipid accretion (determined by the deuterium dilution technique), daily gain and feed intake during the course of growth from 30 to 140 kg body weight. Quantitative trait loci (QTL) detection was conducted using least-squares regression interval mapping. Highest significance at the 0.1% chromosome-wise level was obtained for five QTL: AutoFOM belly weight on SSC1; ham lean-meat weight, percentage of fat of primal cuts and daily feed intake between 60 and 90 kg live weight on SSC6; and loin lean-meat weight on SSC13. QTL affecting daily gain and protein accretion were found on SSC1 in the same region. QTL for protein and lipid content of empty body at 60 kg liveweight were located close to the ryanodine receptor 1 (RYR1) locus on SSC6. On SSC13, significant QTL for protein accretion and feed conversion ratio were detected during growth from 60 to 90 kg. In general, additive genetic effects of alleles originating from the Piétrain line were associated with lower fatness and larger muscularity as well as lower daily gain and lower protein accretion rates. Most of the QTL for carcass characteristics were found on SSC6 and were estimated after adjustment for the RYR1 gene. QTL for carcass traits, fatness and growth on SSC7 reported in the literature, mainly detected in crosses of commercial lines × obese breeds, were not obtained in the present study using crosses of only commercial lines, suggesting that these QTL are not segregating in the analysed commercial lines. [source] Genetic diversity within and between European pig breeds using microsatellite markersANIMAL GENETICS, Issue 3 2006M. SanCristobal Summary An important prerequisite for a conservation programme is a comprehensive description of genetic diversity. The aim of this study was to use anonymous genetic markers to assess the between- and the within-population components of genetic diversity for European pig breeds at the scale of the whole continent using microsatellites. Fifty-eight European pig breeds and lines were analysed including local breeds, national varieties of international breeds and commercial lines. A sample of the Chinese Meishan breed was also included. Eleven additional breeds from a previous project were added for some analyses. Approximately 50 individuals per breed were genotyped for a maximum of 50 microsatellite loci. Substantial within-breed variability was observed, with the average expected heterozygosity and observed number of alleles per locus being 0.56 [range 0.43,0.68] and 4.5 respectively. Genotypic frequencies departed from Hardy,Weinberg expectations (P < 0.01) in 15 European populations, with an excess of homozygotes in 12 of them. The European breeds were on average genetically very distinct, with a Wright FST index value of 0.21. The Neighbour-Joining tree drawn from the Reynolds distances among the breeds showed that the national varieties of major breeds and the commercial lines were mostly clustered around their breeds of reference (Duroc, Hampshire, Landrace, Large White and Piétrain). In contrast, local breeds, with the exception of the Iberian breeds, exhibited a star-like topology. The results are discussed in the light of various forces, which may have driven the recent evolution of European pig breeds. This study has consequences for the interpretation of biodiversity results and will be of importance for future conservation programmes. [source] | ||||||||||