Association Between FSHB And FSH Receptor Polymorphisms And Serum E2 In Pigs In Estrus

FSHβ/FSHR signaling pathway plays a key role in follicular development and production of estrogen in female animals. Serum E2 is a decisive factor in performance of oestrus symptoms in pigs.We detected the polymorphism of FSHβ and FSHR genes in Large White, Landrace and Chinese Mi pigs and correlated with the serum estrogen. This study was designed to selecte FSHβ and FSH receptor polymorphisms associated with sow estrogen and improve the oestrus symptoms in sows.The results are as follows:1. The polymorphism of FSHβ genes in Large White, Landrace and Chinese Mi pigsThe polymorphisms of FSHβgene were detected in 193 Chinese Mi pigs, Large White and Landrace. Two alleles A and B,and three genotypes AA,AB and BB were found in the three populations.The number of these three genotypes in Mi Pigs was BB>AB>AA,with AA-type as the dominant genotype and the frequency of A and B alleles were 0.8415、 0.1585,respectively. The result in Large White and Landrace Pigs was BB>AB>AA,with BB-type as the dominant genotype and the frequency of A and B were 0.1081、 0.8919,espectively. Obviously, the distribution difference of FSHβ in Large White, Landrace and Mi pigs was significant (P<0.05).2. The polymorphism of FSHR genes in Large White, Landrace and Chinese Mi pigs19 SNPs were discovered in FSHR gene in Large White, Landrace and Mi pigs,locating at-1146,-1142,-1135,-1133,-1111,-1009,-923,-920,-895,-889,-865,-779,-766,-738,-636,-619,-539 and -520,respectively.Three haplotypes were identified:A(TTGCGGCTATCAGGATCAA),B (TTGCGGCTACTGAGGCTAG) and C (ACATTTTCGGTGAAGCTCG).The number of six genotypes in Large White is AB>AC>AA>BC>BB>CC and the frequency of A/B/C were 0.5067,0.2933,0.2000, respectively.It was AA>AB>BC>AC in Landrace and the frequency of A/B/C were 0.8030,0.1515,0.0455, respectively. It was AA>AB>BC>AC in Mi pigs and the frequency of A/B/C were 0.7785,0.2089,0.0127, respectively. A was the dominant haplotype in all the three pigs.There were 13 combined genotypes of FSHβ-FSHR in Large White and the number of the genotypes was AAEE>ABEE>ACEE. There were 7 combined genotypes in Landrace and the number of the genotypes was AAEE>ADEE>ABDE. There were 9 combined genotypes in Mi pigs and the frequency of AADD was 0.5714 as the most advantageous.3. Association between FSHβ and FSHR polymorphisms and serum E2 in pigsSerum estrogen ranges in Large White, Landrace and Mi pigs were 14.25-91.17 pg/ml, 16.29-96.24 pg/ml,20.11-80.71 pg/ml, and the average level were 50.15 pg/ml,58.68 pg/ml,46.65 pg/ml,respectively.Obviously, the average E2 in Large White and Landrace were higher than those in Mi pigs. The difference between Landrace and mi pigs was significant (P<0.01).There was no significant differences between FSHβ polymorphisms and serum E2 in pigs.Serum E2 of DD, DE and EE genotypes in Large White were 65.66 pg/ml,53.30 pg/ml,49.20 pg/ml, respectively. However serum E2 of DD、DE in Mi pigs were 46.30 pg/ml,56.73 pg/ml, respectively.E2 of AA and AC genotypes were extremely significant difference with AB、BB and BC genotypes in Large White (P (0.01). The highest was 63.44±4.183 and the lowest was 39.65±3.242 (pg/ml).There was no significantly difference in Landrace pigs.E2 of AA genotype was 51.03±2.792 (pg/ml) in Mi pigs,however the BB was 35.67±5.433 (pg/ml),it was significantly difference (P (0.05). In addition, E2 of AA genotype in Large White and Landrace was significantly difference with E2 in Mi pigs (P (0.05).E2 of ACEE、AADE and AAEE combined genotypes were extremely higher than ABEE genotype (P <0.01) and higher than BBEE genotype in Large White and Landrace (P (0.05). E2 of the combined genotypes was AADE>AADD>ABDD>BBDD in Mi pigs.There was significantly difference between AADE and BBDD (P (0.05).There was no differenc in other combined genotypes.4. Association between FSHβ and FSHR polymorphisms and litter size in pigsThe DD、DE and EE genotypes were not associated with litter size in Large White. The TNB and NBA of EE were more than DD in Landrace, although the association was not significant.The association of FSHR gene in Large White with the litter size was AB>AA>BB>BC>AC. TNB and NBA of AB genetype were 12.07±0.530 and 11.67±0.637, significantly more than 9.87±0.554 and 9.44±0.577 of BB type (P<0.05)...