Takahisa  Yamada, Bin  Tong, Seiki  Sasaki, Youji  Muramatsu, Takeshi  Ohta, Hiroyuki  Kose, Hideaki  Yamashiro, 
    Polymorphisms in Promoter Regions of <I>MYH1</I> and <I>IRS1</I> Genes Showing Marbling-Associated Expression Changes,
    Journal of Animal and Veterinary Advances,
    Volume 11,Issue 23,
    2012,
    Pages 4441-4445,
    ISSN 1680-5593,
    javaa.2012.4441.4445,
    (https://makhillpublications.co/view-article.php?doi=javaa.2012.4441.4445)
    Abstract: Marbling, defined by the amount and distribution of intramuscular 
  fat is an economically important trait of beef cattle in Japan. Previously, 
  researchers have found that the Myosin Heavy Chain 1 (<I>MYH1</I>) gene coding 
  for an isoform of myosin heavy chain a major contractile protein which converts 
  chemical energy into mechanical energy in muscle which is expressed in slow-twitch 
  oxidative fiber and involved in development of the fiber and Insulin Receptor 
  Substrate 1 (<I>IRS1</I>) gene encoding a signaling adaptor protein which is 
  phosphorylated by insulin receptor and associated with insulin resistance and 
  birth weight, possess expression differences in musculus longissimus muscle 
  between low-marbled and high-marbled steer groups. In the present study, researchers 
  detected Single Nucleotide Polymorphisms (SNPs), g.29850738G&gt;A and g.120947716T&gt;C 
  in the promoter regions of the <I>MYH1 </I>and <I>IRS1</I> genes, respectively 
  between the 2 steer groups. However, the allelic distributions of the 2 SNPs 
  were indistinguishable between Japanese Black sires with extremely high predicted 
  breeding value for marbling and with extremely low one. An unknown SNP in the 
  distal region upstream of ~4 kb proximal promoter regions of the <I>MYH1</I> 
  and <I>IRS1</I> genes might be related to changes in gene expression and/or 
  marbling.
    Keywords: Allelic distribution;gene expression;IRS1;marbling;MYH1;single nucleotide polymorphism