FSHβ Gene Variation Driving Force And Genetic Effects Of FSHR Gene

1. Genetic Signature of Strong Recent Positive Selection at FSHβ Gene in Goats.Follicle stimulating hormone(FSH) is a glycoprotein hormone, secreted by gonadotrophs of the anterior pituitary gland. It regulates the development and functions of gonads and is essential for normal reproductive functions in mammals. Determination of selection is arising as one of the most significant steps in the investigation of multilocus population genetic. This study investigated outlier loci detection using a FST based technique and testing of single nucleotide polymorphisms(SNPs) genotyped in individuals of four goat breeds of China. The utilization of outlier detection approach using SNPs resulted in the identification of the FSHβ to be under selection. Nucleotide sequence of 10 species were also included to determine the evolutionary selection of FSHβ gene and the results showed that this gene previously was under purified selection but recently it is under positive selection. The nucleotide sequence of FSHβ gene of goats showed closer coding sequence similarity to FSHβ gene of ovine(55%), equine(55%) the cattle(54%), rabbit(49%) and human(48%). The outlier loci recognized in this study may be useful to elucidate adaptive variability in the studied species attributed by wide climate variation in their native areas and vigorous import/export which suggest their ability to adapt to a new environment. In conclusion, the FSHβ gene which was previously under purified evolutionary selection is now remarkably under strong positive selection.2. Positive Selection of FSHR Gene, Identification, Characterization of Polymorphisms of FSHR Gene and its effects on Litter Size in Hu Sheep.In this study we exploited the genetic variation of FSHR gene among populations of Hu sheep to discover the previous selection signatures and recent signatures of selection. For this purpose we used Bayesian method for finding differentiated loci based on FST and used it for geographically separated populations of Hu sheep by diverse or identical reproductive goals. We determined the prospect of FST investigation in finding signatures of selection through testing some SNPs in our data set. The outcomes described FST values higher than the expected(P < 10%) for regions of SNP11 i.e(C198T) for exon9 which is hypothesized to be targets for artificial selection. For determining foot prints of selection among species for FSHR gene we used nucleotide database for this gene against 17 species and by using likelihood models for determining selection and found no significant positive selection but we find some positive selection sites 19 S, 329 L, 349 P, and 369 R. We also predicted the protein model of FSHR gene of sheep and located the identified SNPs on the model and we also found SNP C198 T on the conserved domain of the protein structure which can alter its functioning by interacting in the Gn RH pathway. We identified 15 SNPs in FSHR gene 12 from intron and three from exons. Then the identified SNPs were used for the association analysis with litter size and results revealed that three SNPs associated(P<0.1) with litter size from second parity, 2 SNPs(G247T, A249G) from intron and 1 SNP(C198T) from exon9. Intron SNPs from parity two with genotype and frequencies GT(0.18), GG(0.72), TT(0.1) and AG(0.19), AA(0.72), GG(0.09) and for exon9 SNP genotype and frequencies TT(0.63), CT(0.31), and CC(0.06) were identified respectively. For first parity there was no significant association of these SNPs(P<0.1) but for second parity we found the heterozygous ewes with GT and AG genotype had more litter size than the homozygous ewes among SNPs of intron while for second parity in exon9 SNP we found that ewes with TT genotype were having more litter size then the ewes of CT and CC genotypes.