Enhancement of heat tolerance in mice early embryos by TCZB-culture medium.

【Objective】 The modified CZB medium -TCZB for the development of mouse preimplantation embryos was investigated to find a new medium which could increase the heat tolerance of the embryos. 【Method】 The method of prokaryotic expression was used to get Tat-Hsp70 and this Tat-Hsp70 protein was added to CZB medium to prepare TCZB medium. The embryonic development rate (EDR) and hatching rate (HR) between heat stressed group and control group were compared. 【Result】 There was no significant difference in EDR and HR among groups of CZB,TCZB and control after heat stressed at 39℃; however,after treatment at 41℃,both EDR and HR of the control group (83.7±6.1,75.6±4.5) were significantly higher than tnat of both TCZB group (81.3±4.5,76.5±7.6) (P0.05) and CZB group (80.2±5.4,73.4±6.2) (P0.05),and both EDR and HR in the TCZB group was significantly higher than that of CZB group. 【Conclusion】 TCZB improves both EDR and HR of mouse preimplantation embryos heat stressed at 41℃.