Polylmorphisms Of LIF Gene And Its Association With Sows' Litter Sizes

In this study,LIF(leukemia inhibitory factor)gene which is candidated about Animal embryo attachment was selected,its SNPs(single nucleotide polymorphisms)were detected and associated with sows' litter sizes were calculated in three Anhui superior native pig breeds(Anqing Liubai Pig,Wannan Black Pig and Wei Pig)and a Exotic lean pig breed(Large White pig).Primers were designed according to Sus scrofa' LIF(Number:AJ296176)gene which published in NCBI,polymerase chain reaction-single-strand conformation polymor-phism(PCR-SSCP)? cleaved amplification polymorphism sequence-tagged sites(PCR-RFLP)and Bidirectional sequencing of PCR products were used to detected the SNPs and analysis of GLM model in SPSS program were used to detected the genetic variation and its associated with litter size were calculated,to find out the Marker assisted gene related with the little size of the four varieties,and provide a reference for molecular breeding of pigs in the future and a scientific basis for the protection of genetic resources in anhui local varieties.The study show that:(1)The results showed that An C?T mutation in exon 2 at 5709 bp in Anqing Liubai Pig,An C?T mutation in exon 3 at 6646 bp in Anqing Liubai Pig?Wei Pig and Large White Pig,An C?T mutation in exon 3 at 6988 bp in Wei Pig and Large White Pig.(2)The results of population genetics analysis show that 2 genotypes(CC and TT)were found in LIFg.C5709 T in Anqing Liubai Pig.The genotypic frequency of CC was 70.71%respectively,and CT was 29.29% respectively,the polymorphism information content(PIC)was 0.2188 in Anqing Liubai population,it was in low polymorphism situation.?~2 test showed that the gene frequencies and genotype frequencies have reached the Hardy-Weinberg equilibrium(P>0.05)in Anqing Liubai Pig in LIFg.C5709 T.3 genotypes(AA?AB and BB)were found in LIFg.C6646 T in Anqing Liubai Pig?Wei Pig and Large White pig.The genotypic frequency of AA was 47.47%?57.14% ?50.62% respectively,AB was 42.42%?35.16% ?35.80% respectively,BB was 10.11%?7.70%?13.58%respectively,the polymorphism information content(PIC)was 0.3377?0.3064?0.3383 in Anqing Liubai population?Wei Pig population and Large White pig population.they were all in average polymorphism situation.?~2test showed that the gene frequencies and genotype frequencies have reached the Hardy-Weinberg equilibrium(P>0.05)in LIFg.C6646 T.3 genotypes(DD?DE and EE)were found in LIFg.C6988 T in Wei Pig and Large White pig.The genotypic frequency of DD was 45.05%?45.91%respectively,DE was 32.97% ? 39.51% respectively,EE was 21.98% ? 13.58% respectively,thepolymorphism information content(PIC)was 0.3613?0.3457 in Wei Pig population and Large White pig population.they were all in average polymorphism situation.?~2 test showed that the gene frequencies and genotype frequencies have reached the Hardy-Weinberg equilibrium(P>0.05)in LIFg.C6988 T.(3)The associated of polymorphism of LIF gene with carcass and litter sizes were analysed.In Anqing Liubai population of LIFg.C5709 T,the total number born and born ablive genotype differences were not significant(P>0.05).However,there are a trend of CC type higher than the CT type in the gilts and sows.In LIFg.C6646 T of Anqing Liubai Pig,BB type of the gilts was higher than AA and AB type in TBA and NBA(P<0.01),AB type was higher than AA type(P<0.01);BB type of the sows was higher than Aa type in TBA and NBA((P<0.01).In Large White pig,AA type of the gilts was higher than AB and BB type in TBA and NBA(P<0.01),AA type of the sows was higher than BB type in TNB(P<0.05),AA type was higher than AB type in NBA(P<0.01).In LIFg.C6988 T of Wei Pig,DD type was higher than DE and EE type in TBA and NBA(P<0.01).In Large White pig,DD type of the gilts was higher than DE and EE type in TBA and NBA(P<0.01);DD type of the sows was higher than DE and EE type in TNB(P<0.01),DD type was higher than DE and EE type in NBA(P<0.01),DE type was higher than EE type in NBA(P<0.01).(4)The study suggest that LIFg.C6646 T site can be used as the candidate genetic marker of Sow Litter Size in Anqing Liubai Pig and Large White Pig,LIFg.C6988 T site can be used as the candidate genetic marker of Sow Litter Sizes in Wei Pig and Large White Pig,to apply to the improvement of sow litter sizes.