Association Analysis Of FSHβand PRL Gene’s Polymorphisms With The Egg Production In Ning-du Yellow Chicken

Ning-du Yellow Chicken is our precious local chicken breed, which is in a smallsize and for meat with high-quality, rich in prominent prematurity and meat qualitycharacteristics, however, relatively low reproductive performance. Improve reproductiveperformance of Ning-du Yellow Chicken has become one of our problems to be solved.In the study, Ning-du Yellow Chicken including B1(105birds), B2(139birds), twogroups of244individual birds were selected as experimental materials,Follicle-stimulating hormone beta subunit gene (FSHβ) and Prolactin gene(PRL)as acandidate gene, direct sequencing was applied to detect single nucleotide polymorphism(SNP) of FSHβ gene5’UTR and PRL gene5’ UTR, the second intron (Intro2) and thethird exon (Exon3) and other regions of Ning-du Yellow Chicken, and PCR-RFLPtechnique was introduced to do correlational research in partial SNP locus layingperformance of Ning-du Yellow Chicken, the results were as follows.1. In the5’UTR of FSHβ gene four mutations were detected, namely T-470A,A-464G, A-405G, T-250C, this showed the existence of a wealth of single nucleotide acidvariation in FSHβ gene5’ end of Ning-du Yellow Chicken.2. Three genotypes of mutation site A-405G in FSHβ gene has significantcorrelation with egg production of280days,300days,330days old of samples of B1batch; While was significantly correlated (P <0.05) with egg number of300days,330days old of B2samples batch; Age at first egg of GG genotype samples of B1, B2batches were earlier than AA and AG genotypes, but the difference was not significant (P>0.05). Batch effect of all samples was corrected with R software, further correlationanalysis results showed that the variable site has no significant correlation(P <0.05)with laying performance the measured samples of Ning-du yellow chicken, the sameproduction opened GG genotype AA and earlier age AG genotype, but the difference wasnot significant (P>0.05). To sum up foregoing analysis results, GG genotype openproduced earlier than AA and AG genotypes, but the difference was not significant (P>0.05), indicating that the site can be used as effective molecular marker in early layingperformance breeding in Ning-du Yellow Chicken.3. Eight SNP loci were found in the PRL gene, including one SNP loci in5’ UTR (T4846A), seven SNP loci in Intron2(T6358C, T6384C, T6445G, G6501A, G6550A,T6608C, GA deletion in6625), which showed there were rich single nucleotidevariations in PRL gene of Ning-du Yellow Chicken.4. Three genotypes of mutation site T6358C in PRL gene has no significantcorrelation with egg production traits of the samples of B1batch, but the TT genotypeshowed the best laying performance, is optimal genotype; while it has a significant correlation (P <0.05) with both age at first egg and egg number of200days of age,240days old, similarly, the GG genotype showed optimal laying performance, not only earlyage at first egg, but the largest egg number; followed by CT genotype, and CC genotypeshowed the worst laying performance. Batch effect of all samples was corrected with Rsoftware, further correlation analysis results showed that the variable site wassignificantly correlated (P <0.01) with age at first egg of Ning-du Yellow Chicken, thepredominant genotype were TT> CT> CC successively, TT genotype is average9.353days earlier than CC on production (P<0.05), while average9.564more in200-day-oldegg number (P <0.05). Therefore, PRL can be used as a candidate gene formarker-assisted selection (MAS) and individuals with the TT genotype selected toimprove Ning-du Yellow Chicken egg production traits.