Polymorphism And Expression Of ADIPOQ,ADIPORs And Its Association With Litter Size In Swine

Reproductive traits is one of the important economic traits in pig,which is mainly measured as total number born(TNB)and number born alive(NBA).Reproductive capacity of sow is mainly regulated by hypothalamus-pituitary-gonadal axis.Adiponectin(ADIPOQ)is a hormone secreted mainly by adipose tissue,which affects animals reproductive hormones secretion mediated by its receptors,ADIPOR1 and ADIPOR2.This research mainly contains the following two aspects: 1.Analyzing polymorphisms of ADIPOQ gene,ADIPOR1 gene and ADIPOR2 gene in Wannan black pigs,Berkshire×Wannan black pigs and Berkshire pigs by PCR-SSCP technology,while doing linkage disequilibrium analysis of constructing genome and analyzing the relationship between polymorphisms and sow reproductive capacity;2.Using qRT-PCR to compare the GnRH mRNA,ADIPOR1 mRNA and ADIPOR2 mRNA expression level of transcription in hypothalamus tissue,GnRHR mRNA and the LH? mRNA expression level of transcription in pituitary tissue,and LHR mRNA expression level of transcription in ovary tissue of Wannan black pigs,American large white pigs(Low fertility)and Danish large white pigs(High fertility),and analyzing the correlation between ADIPORs and reproductive hormones.The results of SSCP showed that the ADIPOQ gene were found three polymorphisms c.178G>A,c.1165A>G and c.1138G>A.c.178G>A and c.1165A>G are linkage disequilibrium.In Wannan black pigs c.178G>A,primiparity of AG genotype at TNB(TNB)and NBA(born alive litter)was significantly higher than that of AA genotype(P<0.05).In c.1138G>A sites,CD genotype has more litter size.Multiparity of Berkshire×Wannan black pigs,c.1138G>A sites,NBA and TNB of CD genotype was significantly higher than that of DD genotype(P<0.05).ADIPOR1 gene found one polymorphic loci c.759G>A,primiparity of Wannan black pigs,NBA and TNB of EF genotype was significantly higher than that of FF genotype(P<0.05).ADIPOR2 gene found one polymorphic loci c.672T>C,primiparity of Wannan black pigs,NBA and TNB of CC genotype was significantly higher than that of TT genotype and TC genotype(P<0.05),multiparity Wannan of black pigs,NBA and TNB of TC genotype and CC genotype was significantly higher than that of TT genotype(P<0.05).The results indicated that polymorphisms of ADIPOQ gene,ADIPOR1 gene and ADIPOR2 gene was related with the litter size of sow.The results of qRT-PCR showed that in hypothalamus,the expression of GnRH mRNA of Wannan Black pigs was higher than that of American large white pigs(Low fertility)on the trend(P=0.07);The expression of ADIPOR1 mRNA of Wannan Black pigs was lower than that of American large white pigs on the trend(P=0.07);The expression of ADIPOR2 mRNA of Wannan Black pigs was significantly higher than that of American large white pigs(P<0.05).and these three gene expression of Wannan Black pigs have no difference with that of Danish large white pigs(High fertility).In pituitary,the expression of GnRHR mRNA of Wannan Black pigs was lower than that of American large white pigs on the trend(P=0.08);The expression of LH? mRNA of Wannan Black pigs was significantly higher than that of American large white pigs(P<0.05),and these two gene expression of Wannan Black pigs have no difference with that of Danish large white pigs.In ovary,the expression of LHR mRNA of Wannan Black pigs was significantly lower than that of American large white pigs(P<0.05),but there is no difference with Danish large white pigs.There was significant negative correlation between ADIPOR1 mRNA and GnRH mRNA in hypothalamus(P<0.05).The results indicated that the expression patterns of reproductive genes were different between low and higher fertility breeds.Besides,ADIPOQ may regulate the secretion of GnRH by ADIPOR1,which may affect sow reproductive activity.