The Linkage Map Construction Of Chicken's Short Arm Of Chromosome 2 And The Linkage Analysis Of Rose Comb Trait

In this study, three Tulufan fighting cocks and six rose comb hens both with the homozygous comb genotype were chosen as the parents through test cross.Using F2 and backcross experimental design, we cumulatively collected some individuals with comb trait record. Among the individuals, F1 generation had twenty-eight individuals (all walnut comb), of which six were cock, twenty-two were hen; F2 generation had seven hundred and thirteen individuals, including four hundred and three walnut comb individuals, one hundred and forty-seven rose comb individuals, one hundred and nineteen pea comb individuals, and only forty-four single comb individuals; backcross population had sixty-seven individuals, of which thirty-two were pea comb individuals, thirty-five were walnut comb individuals. By the chi square test, the proportion of four combs of the F2 generation was accorded with 9:3:3:1, and the backcross population's comb proportion was in line with 1:1, which were both consistent with the discussion of classical genetics.Based on the published genetic linkage map of chicken, seventeen microsatellite markers were selected in the chicken's short arm of chromosome two(ADL0228,ABR0336,ABR0020,ABR0004,MCW0082,MCW0341,ADL0270,LEI0320,LEI0117,MCW0247,ADL0309,MCW0131,LEI0086,MCW0239,ADL0120,MCW0065,ADL0257) for the genetic structure analysis of experimental population. Meanwhile, we used Crimap2.4 and MapDraw2.1 software to build the genetic linkage map of this group's short arm of chromosome two, and combined with phenotypic records to analyse the mapping of comb trait, the results were as follows:1,The seventeen microsatellite loci all showed higher heterozygosity and polymorphic information content in the experimental population. The average population heterozygosity was 0.6900 (0.3396-0.9196), and the polymorphic information content was between 0.3003 and 0.7017. It can be seen that the seventeen loci were moderate or high polymorphic, they can be used as effective genetic markers for the construction of genetic linkage map.2,By using Crimap2.4 and MapDraw2.1 software, the seventeen microsatellite loci were employed to build the genetic linkage map of this family's short arm of chromosome two. The result was that except MCW0341, the remaining 16 loci could be linked, and the total length of linkage map constructed was 165.6cM, the average density of the markers was 10.35cM.3,Combined with phenotypic traits record, the linkage analysis was made between the comb traits and seventeen microsatellite loci by using log odds scoring method, and there loci preliminary discovered in the short arm of chromosome two were linked with the rose gene (ADL0270,LEI0117and MCW0247), of which the locus MCW0247 had the closest linkage with the rose gene, and the genetic distance was 0.31cM.