Association analysis between variants in KISS1 gene and litter size in goats

Xiaopeng An,Teng Ma,Jinxing Hou,Binyun Cao,Peng Han,Yan Yan,Yunxuan Song,Fang Fang,Haibo Zhao,Jiangang Wang

doi:10.1186/1471-2156-14-63

Abstract

BackgroundKisspeptins are the peptide products of KISS1 gene, which operate via the G - protein-coupled receptor GPR54. These peptides have emerged as essential upstream regulators of neurons secreting gonadotropin-releasing hormone (GnRH), the major hypothalamic node for the stimulatory control of the hypothalamic–pituitary– gonadal (HPG) axis. The present study detected the polymorphisms of caprine KISS1 gene in three goat breeds and investigated the associations between these genetic markers and litter size.ResultsThree goat breeds (n = 680) were used to detect single nucleotide polymorphisms (SNPs) in the coding regions with their intron–exon boundaries and the proximal flanking regions of KISS1 gene by DNA sequencing and PCR–RFLP. Eleven novel SNPs (g.384G>A, g.1147T>C, g.1417G>A, g.1428_1429delG, g.2124C>T, g.2270C>T, g.2489T>C, g.2510G>A, g.2540C>T, g.3864_3865delCA and g.3885_3886insACCCC) were identified. It was shown that Xinong Saanen and Guanzhong goat breeds were in Hardy-Weinberg disequilibrium at g.384G>A locus (P < 0.05). Both g.2510G>A and g.2540C>T loci were closely linked in Xinong Saanen (SN), Guanzhong (GZ) and Boer (BG) goat breeds (r2 > 0.33). The g.384G>A, g.2489T>C, g.2510G>A and g.2540C>T SNPs were associated with litter size (P<0.05). Individuals with AATTAATT combinative genotype of SN breed (SC) and TTAATT combinative genotype of BG breed (BC) had higher litter size than those with other combinative genotypes in average parity. The results extend the spectrum of genetic variation of the caprine KISS1 gene, which might contribute to goat genetic resources and breeding.ConclusionsThis study explored the genetic polymorphism of KISS1 gene, and indicated that four SNPs may play an important role in litter size. Their genetic mechanism of reproduction in goat breeds should be further investigated. The female goats with SC1 (AATTAATT) and BC7 (TTAATT) had higher litter size than those with other combinative genotypes in average parity and could be used for the development of new breeds of prolific goats. Further research on a large number of animals is required to confirm the link with increased prolificacy in goats.

Highlights

Kisspeptins are the peptide products of KISS1 gene, which operate via the G - protein-coupled receptor GPR54
These peptides have emerged as essential upstream regulators of neurons secreting gonadotropinreleasing hormone (GnRH), the major hypothalamic node for the stimulatory control of the hypothalamic–pituitary– gonadal (HPG) axis [1]
To their prominent expression at hypothalamic levels, fragmentary evidences suggest that KISS1 and/or KISS1R mRNAs or proteins are present in several peripheral reproductive tissues including the ovary [9,10], oviduct [11] and testes [12]

Summary

Introduction

Kisspeptins are the peptide products of KISS1 gene, which operate via the G - protein-coupled receptor GPR54 These peptides have emerged as essential upstream regulators of neurons secreting gonadotropin-releasing hormone (GnRH), the major hypothalamic node for the stimulatory control of the hypothalamic–pituitary– gonadal (HPG) axis. Kisspeptins are the peptide products of KISS1 gene, which operate via the G - protein-coupled receptor GPR54 ( known as KISS1R) These peptides have emerged as essential upstream regulators of neurons secreting gonadotropinreleasing hormone (GnRH), the major hypothalamic node for the stimulatory control of the hypothalamic–pituitary– gonadal (HPG) axis [1]. They are potent elicitors of gonadotropin secretion in various species and physiological settings. These findings indicate that KISS1 gene is an excellent candidate gene for reproductive traits in human and livestock

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