Association of a single nucleotide polymorphism in <it>titin </it>gene with marbling in Japanese Black beef cattle

• Main Authors: Fujita Tatsuo, Morimatsu Fumiki, Murakami Hiroshi, Morita Mitsuo, Takahagi Youichi, Yoshioka Sachiyo, Sukegawa Shin, Sasaki Seiki, Yamada Takahisa, Miyake Takeshi, Sasaki Yoshiyuki
• Format: Article
• Language: English
• Published: BMC 2009-05-01
• Series: BMC Research Notes
• Online Access: http://www.biomedcentral.com/1756-0500/2/78

<p>Abstract</p> <p>Background</p> <p>Marbling defined by the amount and distribution of intramuscular fat is an economically important trait of beef cattle in Japan. We have recently reported that single nucleotide polymorphisms (SNPs) in the <it>endothelial differentiation</it>, <it>sphingolipid G-protein-coupled receptor</it>, <it>1 </it>(<it>EDG1</it>) gene were associated with marbling in Japanese Black beef cattle. As well as <it>EDG1</it>, the <it>titin </it>(<it>TTN</it>) gene, involved in myofibrillogenesis, has been previously shown to possess expression difference in <it>musculus longissimus </it>muscle between low-marbled and high-marbled steer groups, and to be located within genomic region of a quantitative trait locus for marbling. Thus <it>TTN </it>was considered as a positional functional candidate for the gene responsible for marbling. In this study, we explored SNP in <it>TTN </it>and analyzed association of the SNP with marbling.</p> <p>Findings</p> <p>A SNP in the promoter region of <it>TTN</it>, referred to as <it>g.231054C>T</it>, was the only difference detected between high- and low-marbled steer groups. The SNP was associated with marbling in 3 experiments using 101 sires (<it>P </it>= 0.004), 848 paternal half-sib progeny steers from 5 sires heterozygous for the <it>g.231054C>T </it>(<it>P </it>= 0.046), and 820 paternal half-sib progeny steers from 3 sires homozygous for <it>C </it>allele at the <it>g.231054C>T </it>(<it>P </it>= 0.051), in Japanese Black beef cattle. The effect of genotypes of the SNP on subcutaneous fat thickness was not statistically significant (<it>P </it>> 0.05).</p> <p>Conclusion</p> <p>These findings suggest that in addition to the <it>EDG1 </it>SNPs, the <it>TTN </it>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. Further replicate studies will be needed to confirm the allelic association observed here, and to expand the results to evaluate all possible genotypic combinations of alleles.</p>