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F2 Individuals (f2 + individual)
Selected AbstractsEthanol-Responsive Genes (Crtam, Zbtb16, and Mobp) Located in the Alcohol-QTL Region of Chromosome 9 Are Associated With Alcohol Preference in MiceALCOHOLISM, Issue 8 2009Julia Weng Background:, Previously, our group identified cytotoxic and regulatory T-cell molecule (Crtam), zinc finger and BTB domain containing 16 (Zbtb16), and myelin-associated oligodendrocytic basic protein (Mobp) as ethanol-responsive genes in the mouse brain by gene expression profiling. In this study, we used a genetic co-segregation analysis to assess the association of Crtam, Zbtb16, and Mobp with the alcohol preference (AP) phenotype in the alcohol-preferring C57BL/6J (B6) and alcohol avoiding DBA/2J (D2) strains of mice. Methods:, Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to confirm previous microarray analysis results that Crtam, Zbtb16, and Mobp brain mRNA levels in the B6 and D2 strains are altered by ethanol treatment. The association of the 3 genes with AP was assessed in a F2 population (n = 427) derived from the reciprocal crosses involving the B6 and D2 strains. Each F2 individual was assessed for their AP using the 2 bottle choice test and genotyped for Crtam, Zbtb16, and Mobp single nucleotide polymorphisms (SNPs) that differ between B6 and D2 mice. Results:, Semi-quantitative RT-PCR analysis confirmed that Crtam, Zbtb16, and Mobp are ethanol-responsive genes. The SNP analyses show that alleles of the 3 genes co-segregate with the AP phenotype in F2 mice, where individuals homozygous for the B6 allele have higher AP than those homozygous for the D2 allele. Also, the Crtam,Zbtb16 loci that are tightly linked and the Mobp locus act in an additive fashion in determining the relative AP phenotype. Conclusion:, Our results are consistent with the hypothesis that Crtam, Zbtb16, and Mobp may be involved in AP in mice. The nature of this association remains to be established and may reflect a direct effect of these genes or an indirect effect caused by linked genes on mouse chromosome 9. [source] Identification of monozygous twins and microsatellite mutation rate in pigs from QTL linkage analysis dataJOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 5 2001L. Grapes In previous work, microsatellite markers have primarily been tools for genome studies. However, the use of marker data can be extended beyond its original intent to maximize the amount of information obtained. There have been few studies to determine the occurrence of monozygous (MZ) twins in pigs. The advent of DNA marker technology, and microsatellites in particular, allows MZ twins to be identified based on their genotype data. To determine if MZ twin births occur in pigs, genotypes for F2 individuals, n=525, from 65 Berkshire × Yorkshire families were examined. One pair of female twins was found to have matching genotype data (95% CI: 0,2.94 twins). This is a unique result since there have been no published reports to date of twin pigs that survived until birth. Additionally, three dinucleotide microsatellite mutations were found after screening 134 565 meioses of 125 loci spanning the entire genome and the X chromosome. The average mutation rate for the population, n=570, was 2.23 × 10,5 (95% CI: 6.17 × 10,6,6.51 × 10,5). A mutation rate similar to this was published earlier for dinucleotide repeat microsatellite mutations in swine. Identification de jumeaux monozygotes et taux de mutation des microsatellites à partir de données d, analyse de liaison avec des caractères quantitatifs Jusqu'à présent, les marqueurs microsatelittes ont été principalement utilisés comme outils pour étudier le génome. Cependant, l'utilisation des données de marquage peut être étendue au delà de ce but initial et permet d'obtenir d'autres types d'informations. Au cours des dernières années, il n'y a eu que peu d'études visant à determiner l'existence de jumeaux monozygotes (MZ) chez le porc. L'avènement des techniques de marquage de l'ADN, et plus particulièrement des microsatelittes, permet l'identification de jumeaux MZ sur la base de leur génotype aux marqueurs. Afin de déterminer s'il existe des jumeaux MZ chez le porc, nous avons examiné les génotypes d'individus F2 (n=525) issus de 65 familles Berkshire × Yorkshire. La recherche d'individus ayant un genotype identique a permis d'identifer un couple de jumeaux femelles (95% CI: 0,2.94). Il s'agit d'un résultat unique car jusqu'à ce jour, il n'y avait aucun cas publié de jumeaux ayant survécus après la naissance chez le porc. Par ailleurs, après analyse de 134 565 méioses pour 125 loci répartis sur l'ensemble du génome et sur le chromosome X, 3 mutations ont été trouvées au niveau de microsatelittes dinucleotidiques. Le taux moyen de mutation dans la population (n=570) a été estiméà 2.23 × 10,5 (95% IC: 6.17 × 10,6à 6.51 × 10,5). Un taux de mutation similaire à celui-ci a été publié précédemment pour des marqueurs microsatelittes dinucleotidiques chez le porc. [source] Molecular Tagging and Mapping of Quantitative Trait Loci for Lint Percentage and Morphological Marker Genes in Upland CottonJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 3 2006Wang-Zhen Guo Abstract Using 219 F2 individuals developed by crossing the genetic standard line TM-1 and the multiple dominant marker line T586 in Gossypium hirsutum L., a genetic linkage map with 19 linkage groups was constructed based on simple sequence repeat (SSR) markers. Compared with our tetraploid backboned molecular genetic map from a(TM-1 × Hai 7124) × TM-1 BC1 population, 17 of the 19 linkage groups were combined and anchored to 12 chromosomes (sub-genomes). Of these groups, four morphological marker genes in T586 had been mapped into the molecular linkage map. Meanwhile, three quantitative trait loci for lint percentage were tagged and mapped separately on the A03 linkage group and chromosome 6. (Managing editor: Li-Hui Zhao) [source] Association between ovocalyxin-32 gene haplotypes and eggshell quality traits in an F2 intercross between two chicken lines divergently selected for eggshell strengthANIMAL GENETICS, Issue 5 2010H. Takahashi Summary Broken and cracked eggshells contribute significantly to economic losses in the egg production industry. We previously identified ovocalyxin-32 as a potential gene influencing eggshell traits, by analysing an intercross between two parent lines developed from the same founder population by a two-way selection for eggshell strength with non-destructive deformation (DEF) conducted over 14 generations. We determined the nucleotide sequences of six ovocalyxin-32 exons in the parent individuals and analysed the association between ovocalyxin-32 and eggshell traits in the F2 individuals. We identified three haplotypes (W, M and S) of ovocalyxin-32 in the parent individuals. A mismatch amplification mutation assay was performed to distinguish six diplotype individuals (WW, MM, SS, WM, MS and WS) in the F2 population. The egg weight (EW) of SS-diplotype individuals was significantly higher than that of WW-, WM- and WS-diplotypes. Short length of the egg (SLE) of SS-diplotype individuals was significantly higher than that of WW-, WM- and MS-diplotypes. Long length of the egg (LLE) of SS-diplotype individuals was significantly higher than that of WM- and WS-diplotypes. DEF of WW-diplotype individuals was significantly higher than that of SS-, WM, MS and WM-diplotypes. Haplotypic effect analyses showed significant differences between the W-haplotype and the S-haplotypes in the EW, SLE, LLE and DEF. The DEF of M-haplotype was significantly lower than that of W- and S-haplotypes. These results suggest that S- and M-haplotypes are critical for high quality of eggshells in the F2 population. In conclusion, ovocalyxin-32 is a useful marker of eggshell traits and can be used to develop strategies for improving eggshell traits in commercial layer houses. [source] Grey plumage colouration in the duck is genetically determined by the alleles on two different, interacting lociANIMAL GENETICS, Issue 1 2010Y. Gong Summary Based on the observation of a grey phenotype in the F1 generation from a cross between two white plumage duck varieties, the white Kaiya and the white Liancheng, we hypothesized a possible interaction between two autosomal loci that determine grey plumage. Using the parental and F1 individuals, seven testing combinations including five different F1 intercrosses (F2) and two different backcrosses (BC1 and BC2) were designed to test our hypothesis. It was demonstrated by chi-squared analysis that six test matings produced offspring in the expected ratios between the grey and white, with P- values ranging from 0.50 to 0.99. Another mating, where all white offspring were expected, produced 33 white individuals. These results verified that the interaction between two loci produced the grey phenotype. The C locus, which carries the recessive allele (c), was previously thought to be the only gene responsible for white plumage in the duck. This is the first report that an allele (t), carried by the white Liancheng at a different autosomal locus, also determines white plumage in ducks. Furthermore, the dominant alleles at both loci can interact with each other to produce the grey phenotype, and a new dark phenotype, observed in some F2 individuals, can be attributed to the dosage effect of the T allele. [source] Mapping quantitative trait loci regulating chicken body composition traitsANIMAL GENETICS, Issue 6 2009Y. Gao Summary Genome scans were conducted on an F2 resource population derived from intercross of the White Plymouth Rock with the Silkies Fowl to detect QTL affecting chicken body composition traits. The population was genotyped with 129 microsatellite markers and phenotyped for 12 body composition traits on 238 F2 individuals from 15 full-sib families. In total, 21 genome-wide QTL were found to be responsible for 11 traits, including two newly studied traits of proventriculus weight and shank girth. Three QTL were genome-wide significant: at 499 cm on GGA1 (explained 3.6% of phenotypic variance, P < 0.01) and 51 cm on GGA5 (explained 3.3% of phenotypic variance, P < 0.05) for the shank & claw weight and 502 cm on GGA1 (explained 1.4% of phenotypic variance, P < 0.05) for wing weight. The QTL on GGA1 seemed to have pleiotropic effects, also affecting gizzard weight at 490 cm, shank girth at 489 cm and intestine length at 481 cm. It is suggested that further efforts be made to understand the possible pleiotropic effects of the QTL on GGA1 and that on GGA5 for two shank-related traits. [source] |