title: Genetic polymorphisms and protein structures in growth hormone, growth hormone receptor, ghrelin, insulin-like growth factor 1 and leptin in Mehraban sheep.
abstract: The somatotropic axis, the control system for growth hormone (GH) secretion and its endogenous factors involved in the regulation of metabolism and energy partitioning, has promising potentials for producing economically valuable traits in farm animals. Here we investigated single nucleotide polymorphisms (SNPs) of the genes of factors involved in the somatotropic axis for growth hormone (GH1), growth hormone receptor (GHR), ghrelin (GHRL), insulin-like growth factor 1 (IGF-I) and leptin (LEP), using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and DNA sequencing methods in 452 individual Mehraban sheep. A nonradioactive method to allow SSCP detection was used for genomic DNA and PCR amplification of six fragments: exons 4 and 5 of GH1; exon 10 of GH receptor (GHR); exon 1 of ghrelin (GHRL); exon 1 of insulin-like growth factor-I (IGF-I), and exon 3 of leptin (LEP). Polymorphisms were detected in five of the six PCR products. Two electrophoretic patterns were detected for GH1 exon 4. Five conformational patterns were detected for GH1 exon 5 and LEP exon 3, and three for IGF-I exon 1. Only GHR and GHRL were monomorphic. Changes in protein structures due to variable SNPs were also analyzed. The results suggest that Mehraban sheep, a major breed that is important for the animal industry in Middle East countries, has high genetic variability, opening interesting prospects for future selection programs and preservation strategies.
authors.affiliation: Department of Animal Science, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Islamic Republic of Iran. a.bahrami@ut.ac.ir
authors.forename: A
authors.initials: A
authors.lastname: Bahrami
authors.forename: Sh
authors.initials: Sh
authors.lastname: Behzadi
authors.forename: S R
authors.initials: SR
authors.lastname: Miraei-Ashtiani
authors.forename: S-G
authors.initials: SG
authors.lastname: Roh
authors.forename: K
authors.initials: K
authors.lastname: Katoh
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001947:Breeding; D005787:Gene Frequency; D054439:Ghrelin / Q000737:chemistry / Q000235:genetics*; D013006:Growth Hormone / Q000737:chemistry / Q000235:genetics*; D007334:Insulin-Like Growth Factor I / Q000737:chemistry / Q000235:genetics*; D020738:Leptin / Q000737:chemistry / Q000235:genetics*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017354:Point Mutation; D020641:Polymorphism, Single Nucleotide; D018807:Polymorphism, Single-Stranded Conformational; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011986:Receptors, Somatotropin / Q000737:chemistry / Q000235:genetics*; D034561:Sheep, Domestic / Q000235:genetics*
chemical_list: D054439:Ghrelin; D020738:Leptin; D011986:Receptors, Somatotropin; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone
keywords: GH; GHR; GHRL; Ghrelin; Gln; Glu; Growth hormone; Growth hormone receptor; IGF-I; Insulin-like growth factor 1; LEP; Leptin; MAS; PCR–SSCP; Protein structures; QTL; SAS; SNP; Tyr; ghrelin gene; glutamic acid; glutamine acid; growth hormone gene; growth hormone receptor gene; insulin-like growth factor 1 gene; leptin gene; marker-assisted selection; polymerase chain reaction–single-stranded conformation polymorphism; quantitative trait loci; single nucleotide polymorphism; statistical analysis system; tyrosine acid