The Important Candidate Genes in Goats - A Review

Abstract

A total of 271 candidate genes have been detected in goats. However, comprehensive investigations have been carried out on the polymorphism of some genes, involved in the control of economic traits. Candidate genes have an effect on the physiological pathway, metabolism and expression of phenotypes. For growth traits, growth hormone (GH), growth hormone receptor (GHR), insulin like growth factor I (IGF-I), leptin (LEP), caprine pituitary specific transcription factor-1 (POU1F1), caprine myostatin (MSTN) and bone morphogenetic protein (BMP) genes are necessary for bone formation, birth weight, weaning weight, body condition and muscle growth. For reproduction, forkhead box L 2 (FOXL2), melatonin receptor 1A (MTNR1A), sex determination region of Y chromosome (SRY) and amelogenin (AMEL) genes influence sex determination and proliferation. The major candidate genes for milk yield and milk composition traits are the casein gene and their family. Keratin associated protein (KAP) and melanocortin 1 receptor (MC1R) genes are candidate genes for wool traits. The major histocompatibility complex (MHC) gene is considered important for the immune system and disease resistance traits. The functions of these genes on economically important traits are different. Some genes have synergistic or antagonistic effects in nature for expression of phenotypic traits. On the other hand, some genes could control more than one trait. Also, the producers should be concerned with these effects because selection of a single trait by using only a gene could affect other traits. Therefore, the identification of candidate genes and their mutations which cause variations of gene expression and phenotype of economic traits will help breeders to search some genetic markers for these economic traits. It may be used as an aid in the selection of parent stock at an early age in the future.

Keywords

• Candidate genes
• goats