Seiki Sasaki

Association of a single nucleotide polymorphism in titin gene with marbling in Japanese Black beef cattle.

BackgroundMarbling 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 endothelial differentiation, sphingolipid G-protein-coupled receptor, 1 (EDG1) gene were associated with marbling in Japanese Black beef cattle. As well as EDG1, the titin (TTN) gene, involved in myofibrillogenesis, 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 TTN was considered as a positional functional candidate for the gene responsible for marbling. In this study, we explored SNP in TTN and analyzed association of the SNP with marbling.FindingsA SNP in the promoter region of TTN, referred to as g.231054C>T, was the only difference detected between high- and low-marbled steer groups. The SNP was associated with marbling in 3 experiments using 101 sires (P = 0.004), 848 paternal half-sib progeny steers from 5 sires heterozygous for the g.231054C>T (P = 0.046), and 820 paternal half-sib progeny steers from 3 sires homozygous for C allele at the g.231054C>T (P = 0.051), in Japanese Black beef cattle. The effect of genotypes of the SNP on subcutaneous fat thickness was not statistically significant (P > 0.05).ConclusionThese findings suggest that in addition to the EDG1 SNPs, the TTN 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.

Association of a single nucleotide polymorphism in ribosomal protein L27a gene with marbling in Japanese Black beef cattle

Marbling, defined by the amount and distribution of intramuscular fat, is an economically important trait of beef cattle in Japan. The c2-11#2 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 ribosomal protein L27a (RPL27A) gene containing the c2-11#2 EST sequence was considered as a positional candidate for the gene responsible for marbling. In the present study, a single nucleotide polymorphism (SNP) in the promoter region of the RPL27A, referred to as g.3109537C>T, was detected between the 2 steer groups. The SNP was associated with the predicted breeding value for beef marbling standard number by the analyses using Japanese Black beef cattle population. The effect of genotypes of the SNP on the predicted breeding value for subcutaneous fat thickness was not statistically significant. These findings suggest that the RPL27A SNP may be useful for effective marker-assisted selection to increase the levels of marbling in Japanese Black beef cattle.

Association of a single-nucleotide polymorphism in myosin-binding protein C, slow-type (MYBPC1) gene with marbling in Japanese Black beef cattle

Bin Tong*, Seiki Sasaki*, Youji Muramatsu, Takeshi Ohta, Hiroyuki Kose, Hideaki Yamashiro*, Tatsuo Fujita and Takahisa Yamada* *Department of Agrobiology, Faculty of Agriculture, Niigata University, Nishi-ku, Niigata 950-2181, Japan; Department of Nutritional Sciences for Well-being, Faculty of Health Sciences for Welfare, Kansai University of Welfare Sciences, Kashiwara, Osaka 582-0026, Japan; Central Pharmaceutical Research Institute, Japan Tobacco, Inc., Takatsuki, Osaka 569-1125, Japan; Department of Life Science, Division of Natural Sciences, International Christian University, Mitaka, Tokyo 181-8585, Japan; Oita Prefectural Institute of Animal Industry, Takeda, Oita 878-0201, Japan

The G allele at the g.70014208A>G in the MYBPC1 gene associated with high marbling in Japanese Black cattle is at a low frequency in breeds not selected for marbling

1Faculty of Agriculture, Department of Agrobiology, Niigata University, Nishi-ku, Niigata 950-2181, Japan 2Faculty of Health Sciences for Welfare, Department of Nutritional Sciences for Well-being, Kansai University of Welfare Sciences, Kashiwara, Osaka 582-0026, Japan 3Central Pharmaceutical Research Institute, Japan Tobacco Inc., Takatsuki, Osaka 569-1125, Japan 4Department of Life Science, Division of Natural Sciences, International Christian University, Mitaka, Tokyo 181-8585, Japan 5Oita Prefectural Institute of Animal Industry, Takeda, Oita 878-0201, Japan