Lloyd Sally S, Steele Edward J, Valenzuela Jose L, Dawkins Roger L
CY O'Connor ERADE Village Foundation, P.O. Box 5100, Canning Vale South, WA 6155, Australia.
Melaleuka Stud, 24 Genomics Rise, Piara Waters, WA 6112, Australia.
Int J Genomics. 2017;2017:6532837. doi: 10.1155/2017/6532837. Epub 2017 Aug 17.
Traditional analyses of a QTL on Bota 19 implicate a surfeit of candidates, but each is of marginal significance in explaining the deposition of healthy, low melting temperature fat within marbled muscle of Wagyu cattle. As an alternative approach, we have used genomic, multigenerational segregation to identify 14 conserved, ancestral 20 Mb haplotypes. These determine the degree and rate of marbling in Wagyu and other breeds of cattle. The melting temperature of intramuscular fat is highly heritable and traceable by haplotyping. Fortunately, for the production of healthy beef, some of these haplotypes are sufficiently penetrant to be expressed in heterozygous crossbreds, thereby allowing selection of sires which will improve the healthiness of beef produced under even harsh climatic conditions. The region of Bota 19 is syntenic to a region of Hosa 17 known to be important in muscle metabolism and in determining susceptibility to a form of human muscular dystrophy.
对牛19号染色体上一个数量性状基因座的传统分析涉及大量候选基因，但在解释和牛大理石花纹肌肉中健康的、低熔点脂肪的沉积方面，每个候选基因的意义都很有限。作为一种替代方法，我们利用基因组多代分离技术鉴定出14个保守的、祖先的20兆碱基单倍型。这些单倍型决定了和牛及其他牛品种大理石花纹的程度和形成速度。肌内脂肪的熔点具有高度遗传性，可通过单倍型分型进行追踪。幸运的是，为了生产健康牛肉，其中一些单倍型具有足够的外显率，能够在杂合杂交后代中表达，从而可以选择种公牛，即使在恶劣气候条件下生产的牛肉也能提高其健康程度。牛19号染色体上的这个区域与猪17号染色体上的一个区域同线，已知该区域在肌肉代谢以及决定人类某种形式的肌肉萎缩症易感性方面很重要。
