Genetic Trait Of DRB Genes And Its' Polymorphism Association With Antler Productivity In Sika Deer

To conserve sika deer and develop deer breeding continuablely,here investigation of genetic characters of MHC-DRB genes was operated in sika deer.Their polymorphisms were typed in three captive populations,and the feasibility of being genetic marker was discussed for assistant genetic management.The results were revealed as follows:1.A new molecular typing of DRB genes was established in sika deer,i.e.motif specific-PCR-SSCP-direct sequencing.It was compared with PCR-SSCP-cloning sequencing a conventional method.The results indicated artificial alleles from 28 point mutations and 7 recombinations were appeared in the conventional method,and the new method eliminated artificial sequences completely.2.Using this method,15 alleles of DRB genes(named Ceni-DRB1～Ceni-DRB15) were identified in sika deer.34.9%nucleotide sites and 49.4%amino acid sites were variation among these sequences.Because 2-5 alleles were detected for each individual,we can presume the existence of two or more DRB loci in sika deer.Sharing one DRB allele between sika deer and wapiti was discoved firstly,i.e.Ceni-DRB14 is same as Ceel-DRB45.Moreover,two alleles(Ceni-DRB5 and Ceel-DRB35) were differed only one nucleotide or one amino acid between this two species.3.Allele-specific PCR method was found to type DRB genes,which could examine DRB genotype briefly and fleetly in sika deer.14 primers were designed,including 10 forward primers and 4 reverse primers,which were validated by experiment.This method helped to study DRB genes in sika deer conservation genetics.4.Using allele-specific PCR,DRB genes diversities were scaned in Song Huahu,Xi Feng and Xing Kaihu three sika deer populations.The results revealed that only 10 alleles were detected in three populations,and the other 5 alleles were appeared in 10 muscle samples.The frequency of same allele was difference significantly among variational population.12 DRB haplotypes were disclosed in Song Huahu population,and 14 DRB haplotypes were defined in Xi Feng and Xing Kaihu population,respectively.5.Association analysis between DRB genes and antler productivity indicated that DRB3 allele related positively with two bars antler productivity(R=0.376,P＜0.01),but DRB8 and DRB11 two alleles were negative correlation with two bars antler productivity(R=-0.403 and -0.445, respectively,P＜0.01).In Xing Kaihu population,DRB2 allele was also negative correlation with three forks antler productivity(R=-0.27,P＜0.05).Antler productivity of deer with type 1 DRB allelic lineage was 14%greater than heterozygosity(P＜0.05).However,no allele was related with three forks antler productivity in Song Huahu and Xi Feng populations, and there was not difference significantly among DRB allelic lineage in these two populations. Antler productivity of deer with haplotype 111 was 15%lower than haplotype 11111 in three populations(P＜0.05).According to above results,the conclusions were suggested as follows:1.New method i.e.motif specific-PCR-SSCP-direct sequencing could type DRB genes of sika deer exactly.Using this method,15 alleles of DRB genes were identified in captive sika deer population,among which 13 alleles were found firstly.2.Allele-specific PCR method could examine sika deer DRB genotype briefly and fleetly.3.Two or more DRB loci were approved in sika deer,and sharing one DRB allele between sika deer and wapiti was discoved firstly.4.High level polymorphism of DRB genes was maintained in captive sika deer population. It was indicated that artificial selection based on antler could not reduce polymorphism of DRB genes greatly.5.DRB genes worked on productivity of two bars antler obviously,no on productivity of three forks antler.6.MHC genes made important role in immune system and development of antler,which illuminated it could be potential molecular marker for genetic management of captive sika deer population.