The objective of this study was to determine associations of small heat shock proteins (sHSPs) in tenderness development of loins from callipyge and normal genotype lambs. Loins (M. longissimus lumborum) from sixteen lambs across four genotypes were collected throughout 9 days of postmortem aging. The loins from callipyge lambs had more intact desmin and troponin T throughout aging periods, as well as less μ-calpain autolysis and more calpastatin compared to loins from other genotypes (P < 0.05). Delayed onset of apoptosis was found in the callipyge loins indicated by less cytochrome c and more inactive procaspase-3 compared to normal lamb loins (P < 0.05). Less degraded HSP27 was also consistently found in the callipyge loins compared with loins from normal lambs (P < 0.001). The results found up-regulation of anti-apoptotic activities coincided with toughness in callipyge loins, which suggest apoptosis is likely involved in postmortem proteolysis and subsequent meat tenderization.

这项研究的目的是确定小热休克蛋白（sHSPs）在来自Callipyge和正常基因型羔羊的腰肉嫩度发育中的关联。在死后的9天中，收集了来自四种基因型的16只羔羊的腰肉（M. longissimus lumborum）。与来自其他基因型的猪相比，来自老茧的羔羊的猪在整个衰老期间具有更完整的结蛋白和肌钙蛋白T，以及更少的μ-钙蛋白酶自溶作用和更多的钙蛋白酶抑制素（P  <0.05）。与正常的羔羊腰肉相比，在愈伤组织腰肉中发现了细胞凋亡的延迟发作，这表明细胞色素c减少和无活性的procaspase-3增多（P <0.05）。与正常羊羔的腰肉相比，在愈伤组织腰肉中也始终发现降解程度较低的HSP27（P  <0.001）。结果发现，抗凋亡活性的上调与Callipyge腰部的韧性相吻合，这表明凋亡可能与死后蛋白水解和随后的肉嫩化有关。