USDA, ARS, U.S. Meat Animal Research Center, Clay Center, NE 68933-0166, USA.
Anim Genet. 2009 Oct;40(5):713-21. doi: 10.1111/j.1365-2052.2009.01903.x. Epub 2009 Apr 24.
Genome scans in the pig have identified a region on chromosome 2 (SSC2) associated with tenderness. Calpastatin is a likely positional candidate gene in this region because of its inhibitory role in the calpain system that is involved in postmortem tenderization. Novel single nucleotide polymorphisms (SNP) in calpastatin were identified and used to genotype a population (n = 1042) of Duroc-Landrace-Yorkshire swine for association with longissimus lumborum slice shear force (SSF) measured at days 7 and 14 postmortem. Three genetic markers residing in the calpastatin gene were significantly associated with SSF (P < 0.0005). Haplotypes constructed from markers in the calpastatin gene were significantly associated with SSF (F-ratio = 3.93; P-value = 0.002). The levels of normalized mRNA expression of calpastatin in the longissimus lumborum of 162 animals also were evaluated by real-time RT-PCR and were associated with the genotype of the most significant marker for SSF (P < 0.02). This evidence suggests that the causative variation alters expression of calpastatin, thus affecting tenderness. In summary, these data provide evidence of several significant, publicly available SNP markers associated with SSF that may be useful to the swine industry for marker assisted selection of animals that have more tender meat.
猪的全基因组扫描已经确定了与肉质嫩度相关的第 2 号染色体（SSC2）区域。钙蛋白酶抑制剂是该区域的一个可能的候选基因，因为它在钙蛋白酶系统中起抑制作用，而钙蛋白酶系统参与死后嫩化。在钙蛋白酶抑制剂中鉴定了新的单核苷酸多态性（SNP），并用于对杜洛克-兰德瑞斯-约克夏猪的一个群体（n = 1042）进行基因分型，以关联死后第 7 天和第 14 天测量的最长肌横切力（SSF）。三个位于钙蛋白酶抑制剂基因中的遗传标记与 SSF 显著相关（P < 0.0005）。钙蛋白酶抑制剂基因中的标记构建的单倍型与 SSF 显著相关（F 比= 3.93；P 值= 0.002）。通过实时 RT-PCR 还评估了 162 只动物的最长肌中钙蛋白酶抑制剂的归一化 mRNA 表达水平，并与 SSF 最显著标记的基因型相关（P < 0.02）。这一证据表明，引起变异的因素改变了钙蛋白酶抑制剂的表达，从而影响了嫩度。总之，这些数据提供了与 SSF 相关的几个重要的、公开可用的 SNP 标记的证据，这些标记可能对养猪业有用，可以用于选择肉质更嫩的动物的标记辅助选择。
