AGRICULTURAL RESEARCH COMMUNICATION CENTRE www.arccjournals.com *Corresponding author’s e-mail: dibyendu_vet40@yahoo.co.in. Agricultural Reviews, 37 (3) 2016 : 250-254 Print ISSN:0253-1496 / Online ISSN:0976-0539 Growth Hormone Receptor (GHR) gene and its applications in livestock: A review Anamika, Dibyendu Chakraborty*, D. Kumar, Peer Mohd. Azhar, S. Gurdeep Singh, Simran singh and Aakriti Sudan Division of Animal Genetics & Breeding, FVSc&AH, SKUAST-Jammu, R. S. Pura-181 102, Jammu, India. Received: 29-02-2016 Accepted: 03-09-2016 DOI: 10.18805/ag.v37i3.3541 ABSTRACT The Growth Hormone Receptor (GHR) gene provides instructions for making a protein called the growth hormone receptor. The GHR mediates biological actions of growth hormone on target cells by transducing the growth hormone (GH) signal across the cell membrane and inducing transcription of many genes, including insulin-like growth factor-1 (IGF1). The gene coding for bovine GHR gene consists of nine exons. In exon 8 of the bovine GHR gene, T/A nucleotide variation results in to change in tyrosine from phenylalanine in the transmembrane domain of the GHR protein, has been reported to be associated with a major effect on milk yield in cows. GHR (growth hormone receptor) gene has been shown to harbor a causal mutation of a QTL influencing milk yield and composition GHR gene is a polymorphic gene and the polymorphisms are related to different economic traits of different species. The GHR gene influences physical traits and helps to selection of animals. The lengths of the variable TG-repeats in the P1 promoter of the bovine GHR gene are associated with growth rates in young Angus cattle. Due to various functions of GHR are viewed as promising candidate markers for selection purposes in cattle. Thus GHR gene could be a candidate gene for application in marker assisted selection (MAS). Key words: Economic traits, Growth hormone receptor gene (GHR), Polymorphism. In mammals and birds, the growth and development are primarily regulated by the somatotropicaxis. The somatotropic axis, also named neurocrine axis or hypothalamus-pituitary growth axis, consists of essential compounds such as growth hormone (GH), growth hormone releasing hormone (GHRH), insulin-like growth factors (IGF1 and 2), somatostatin (SS), their associated carrier proteins and receptors, and other hormones like insulin, leptin and glucocorticoids or thyroid hormones. GHR is a member of the cytokine/hematopoietin receptor superfamily (Maj et al., 2006) and consists of three functional domains of the extracellular (ligand-binding) domain, the trans-membrane domain and the cytoplasmic domain (signal transducing). The GHR gene provides instructions for making a protein called the growth hormone receptor. This receptor is embedded in the outer membrane of cells throughout the body and is most abundant in liver cells. The growth hormone receptor has three major parts: An extracellular region that sticks out from the surface of the cell, a trans-membrane region that anchors the receptor to the cell membrane, and an intracellular region that transmits signals to the interior of the cell. The extracellular region attaches (binds) to a substance called growth hormone, fitting together like a lock and it’s key. The binding of growth hormone triggers signalling via the intracellular region of the receptor that stimulates the growth and division of cells.This signalling also leads to the production, primarily by liver cells, of another important growth-promoting hormone called insulin- like growth factor I (IGF-I). Organization of GHR gene: The bovine GHR gene has been mapped to BTA 20, between TGLA126 andGMBT41 (Moody et al.,1995). The gene coding for bovine GHR consists of nine exons (numbered 2 to 10) in the translated part and a long 5’-noncoding region that includes nine un-translated exons- 1A through 1I (Jiang and Lucy, 2001). Among them, only exons 1A, 1B and 1C are well characterised; the existence of exons 1D to 1I is based on RACE (Rapid Amplification of cDNA End) analyses only. Exons from the un-translated regions are spliced alternatively resulting in mRNAs differing in the 5’-untranslated region (5’-UTR). Exon 2 encodes a single peptide, exons 3-7 encode the extracellular GH- binding domain, exon 8 encodes the transmembrane domain and exons 9-10 encode an intracellular domain. The GHR gene is used in animals as a nuclear DNA phylogenetic marker (Gonzalez et al., 2007). The exon 10 had first been experienced to explore the phylogeny of the major groups of Rodentia asreported by Adkins et al. (2001) and Blanga- Kanfi et al. (2009). Applications of GHR gene  The GHR gene is used in animals as a nuclea r DNA phylogenetic marker.