Comparison of the single nucleotide polymorphisms and expression of FSHβ and LHβ genes between prolific and non-prolific goat breeds of Kerala

Abstract

Attappady Black and Malabari breeds of goats are native to Kerala, a southern state of India. Attappady Black is a low prolific breed whereas Malabari breed is highly prolific. Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) are the gonadotropins which are considered to be the central hormones controlling prolificacy. The present study aimed to detect presence of SNPs in exonic regions of FSHβ and LHβ and the expression of these gonadotropins in both these breeds. Blood samples were collected from ten does five each from Attappady Black and Malabari goats and the genomic DNA was extracted. Multiple primers were designed based on Ensembl Genome Browser sequences to cover the entire exonic regions of both the genes for SNP detection. Pooled PCR products of FSHβ and LHβ separately from the two breeds were sequenced. Nucleotide sequencing showed synonymous single nucleotide polymorphism T → C, in FSHβ coding sequence, at position 413 (as per FSHβ ENSCHIG00000022859), in both Attappady Black and Malabari goats. Numerous other SNPs both novel and reported were detected in the non-coding regions of FSHβ. In LHβ of Attappady Black goat, an SNP was found at exonic position 455 (G → A) as per LHβ ENSCHIT00000012663.1. This transition resulted in replacement of amino acid arginine (R) with glutamine (Q). Upon individual sequencing of ten each of single birth and multiple birth Attappady Black goat samples, three animals with single birth and five animals with multiple birth showed G → A change in the LHβ transcript at position 455. Pituitary samples were collected from 6 animals each from both the breeds and expressions of both the genes were quantified using qRT-PCR technique. There was no significant difference in pituitary FSHβ expression between breeds. However, there was a significant difference (P < 0.01) in LHβ expression between the two breeds with an increase in expression of 2.61 folds in Attappady Black breed. This study forewarn a main role for LH in the genetic network controlling prolificacy in these goat breeds and this necessitates further investigation with larger sample size and also in other goat breeds.