Characterisation of mutations in Gonadotropin releasing hormone receptor gene (GnRHR) in Markhoz goats

Markhoz goats are raised in Kurdistan regions of Iran, Iraq and Turkey and are a high- quality mohair producing animals. The population of this breed has been decreased from 22,000 heads in 1996 to less than 1,400 heads in 2017. The variation in the kidding size of Markhoz goats makes them an interesting genetic material to study the underlying genetic mechanism of prolificacy. Reproductive traits have a high economic value in goat breeding, but the heritability of such traits is low; therefore, selective breeding as a traditional method will be a slow process for improvement of the reproductive performance. Alternatively, exploring and discovering of prolificacy genes in goat breeds could effectively increase their reproductive performances through marker assisted selection (MAS) that can propose a clarification for improvement in traits. The hypothalamic gonadotropin-releasing hormone receptor (GnRHR) is a key controller of the reproductive system, which stimulates the synthesis and release of LH and FSH in the pituitary gland. Because of the main role of GnRHR in regulating gonadotropin synthesis and release, the GnRHR gene revealed to be a good candidate for mutations associated with reproductive performance. The present study was aimed to identify mononucleotide mutations in Gonadotropin-releasing hormone (GnRH) receptor gene in markhoz goat breed. Blood samples were taken from forty goats from Markhoz breed. Genomic DNA was extracted from the blood samples. A part of Gonadotropin-releasing hormone receptor gene was amplified using PCR; and sequences of PCR products were determined. Data were analyzed using NCBI_BLAST software package. The obtained sequences were aligned with GnRHR sequence (with access ID NM-001285612) using Clustalw software package. Various types of mutation, inserts and deletions were identified in different haplotypes; and results of sequencing analysis showed that 10 haplotypes, 16 mutations, 3 attachments and 4 omission cases exist in investigated sequence. This research appeared the genetic variations in GnRHR gene in Markhoz goats, these variations should be confirmed and investigated for their possible association with reproductive traits in Markhoz breed.

Keywords:

GnRHR , Mutation , Reproduction , Markhoz Goat