title: Association of a single nucleotide polymorphism in akirin 2 gene with marbling in Japanese Black beef cattle.
abstract: BACKGROUND
  Marbling defined by the amount and distribution of intramuscular fat, so-called Shimofuri, is an economically important trait of beef cattle in Japan. The c17-25 expressed sequence tag (EST) has been previously shown to possess expression difference in musculus longissimus muscle between low-marbled and high-marbled steer groups, and to be located within genomic region of a quantitative trait locus for marbling. Thus, the akirin 2 (AKIRIN2) gene containing the c17-25 EST sequence was considered as a positional functional candidate for the gene responsible for marbling. In this study, we explored single nucleotide polymorphism (SNP) in the AKIRIN2 and analyzed association of the SNP with marbling.
  
  
  RESULTS
  A SNP in the 3' untranslated region of the AKIRIN2, referred to as c.*188G>A, was the only difference detected between high- and low-marbled steer groups. The SNP was associated with marbling in 3 experiments using 100 sires (P = 0.041), 753 paternal half-sib progeny steers from 4 sires heterozygous for the c.*188G>A (P = 0.005), and 730 paternal half-sib progeny steers from 3 sires homozygous for the A allele at the c.*188G>A (P = 0.047), in Japanese Black beef cattle. The effect of genotypes of the SNP on subcutaneous fat thickness was not statistically significant (P > 0.05).
  
  
  CONCLUSIONS
  These findings suggest that the AKIRIN2 SNP polymorphism is associated with marbling and may be useful for effective marker-assisted selection to increase the levels of marbling in Japanese Black beef cattle.
authors: Maebashi Institute of Animal Science, Livestock Improvement Association of Japan, Maebashi, Gunma 371-0121, Japan. sasakis@liaj.or.jp
authors: Seiki
authors: S
authors: Sasaki
authors: Takahisa
authors: T
authors: Yamada
authors: Shin
authors: S
authors: Sukegawa
authors: Takeshi
authors: T
authors: Miyake
authors: Tatsuo
authors: T
authors: Fujita
authors: Mitsuo
authors: M
authors: Morita
authors: Takeshi
authors: T
authors: Ohta
authors: Youichi
authors: Y
authors: Takahagi
authors: Hiroshi
authors: H
authors: Murakami
authors: Fumiki
authors: F
authors: Morimatsu
authors: Yoshiyuki
authors: Y
authors: Sasaki