SNPs In Geese GnRH Gene 5'-flank Region And Exon 1 And Association With Egg Production

GnRH,secreted from hypothalamic,plays extremely broad spectrum of biological role.GnRH is one of the most important hormone mainly related to reproduction in avian species.Many scientific studies indicated that GnRH gene was selected as the candidate gene for egg production.In this study,the Wanxi-White goose(n=200),a Chinese excellent mid-bodied spiece,and Rhine goose(n=80)were used to detect SNPs in the GnRH gene by PCR-SSCR By genome compat-ison,4 pairs of primer was designed using Primer Premier5.0 and DnaStar programme to clone the Exon 1 and 5'-flank region of goose GnRH gene.PCR-SSCP method along with fragment sequencing was used in testing gene mutations at Exon1 and 5' -flank region site.Associations between mutation in GnRH gene and egg production were analyzed.Meanwhile,sequencing of Exon 1 and 5' -flank region and mutation detection at gene coding was also analyzed on Rhine goose to make comparison with Wanxi-White goose.The Exon 1 and 5' -flank region of Wanxi-White goose and Rhine goose were cloned(GenBank accession number:EF495207,EF405623).Homological analysis suggested that the homology of Wanxi-White goose 5'-flank region with Rhine and chicken 5'-flank region were 99%and65%, respectively.Polymorphisms of 5'-flank region and exon 1 on Wanxi-White geese and Rhine geese were analyzed. The results showed that,no polymorphic site was detected at exon1 locus,two SNPs were detected at 5' -flank region amplified by F3 and 1 SNP was detected by F4 prime,respectively.Genetic analysis suggested that,in the Wanxi-White goose populationm,two allelic frequencies detected by F3 primer were 0.7 and 0.3,respectively,three genotype(AA,AB and BB)frequencies were 0.62,0.16 and 0.22,respectively.two allelic frequencies detected by F4 were 0.83 and 0.17,respectively. two genotype(CC and CD)frequencies were 0.62 and 0.16,respectively.?2 fitness test suggested that the population was not in Hardy-Weinberg equilibrium at the two site.In the Rhine goose population,allelic frequecies detected by F3 and F4 were 0.625,0.375 and 0.575,0.425 respectively,genotype(EE,EF,FF,MM,MN and NN)fiequencies were 0.525,0.2,0.275,0.4,0.35 and 0.25,respectively.?2 fitness test suggested that the population was not in Hardy-Weinberg equilibrium at the two site.Polymorphic information content(PIC)of polymorphic sites in Wanxi- White goose population detected by F3 and F4 primers were 0.3381 and 0.2424 respectively.PIC of polymorphic sites in Rhine goose population detected by F3 and F4 primers were 0.3589 and 0.3693,respectively.In the Wanxi-White geese population,least square analysis showed that three genotypes detected by F3 primer had significant relation with egg production,the egg production for BB was higher(P＜0.05)than that for AA and AB.In Rhine geese population,least square analysis showed that the egg production for EE and EF(32.5 and 30)were higher(P＜0.05)than that for FF.F3 locus might be a molecular marker for reproduction trait.