Ear fibroblasts derived from Taiwan yellow cattle are more heat resistant than those from Holstein cattle

The objective of this study was to compare the thermotolerances of ear fibroblasts derived from Holstein (H) and Taiwan yellow cattle (Y) and their apoptosis-related protein expressions with (1, 3, 6, 12, and 24 h) or without heat shock treatment. The results showed that the vaginal temperatures of Y (38.4-38.5 °C) were (P<0.05) lower than that of H (38.8 °C) during the hot season. The apoptotic rates of ear fibroblasts derived from Y (6 h: 1.1%; 12 h: 1.6%; 24 h: 2.6%) were lower (P<0.05) than those of cells derived from H (6 h: 1.8%; 12 h: 4.0%; 24 h: 6.9%), respectively, after heat shock (42 °C). The expression level of apoptosis inducing factor (AIF) in ear fibroblasts derived from H was higher (P<0.05) than those derived from Y after the heat shock treatment for 6 h and 12 h, respectively. The level of cytochrome c of ear fibroblasts derived from H was higher (P<0.05) than those derived from Y after the heat shock treatment for 1-12 h, respectively. The abundances of Caspase-3, Caspase-8 and Caspase-9 of ear fibroblasts derived from H were higher (P<0.05) than those of cells derived from Y after 12 h and 24 h of heat shock, respectively; the Bcl-2/Bax ratios of ear fibroblasts derived from H were lower (P<0.05) than those from Y-derived fibroblasts after heated for 1-24 h. The expression level of HSP-70 of Y-derived ear fibroblasts was also higher (P<0.05) than that from H after the same duration of heat shock treatments. Taken together, the thermotolerance of ear fibroblasts derived from Taiwan yellow cattle was better than that of cells derived from Holstein cattle.