Effects Of Thermo Stress On The Expression Of HSP70 And The Relatively Physical And Biochemical Indexes

As one of the main stressors to animal,thermal restricts the development of animal husbandry.Except for the improvement of feeding condition in the process of production,the selection of tolerant individuals and breeds to thermol is also important to improve animals' adaption to the environment.Thus,researching the change laws of relevant molecule markers and physiological and biochemical indices will makes a big sense,by molecular biology and cell biology methods combined with the exploration of stress physiology and biochemistry.Firstly,105 Sanhe heifers and MDBK cells were treated with various degrees of temperature stress,detected the response mode of HSP70 to cold and heat stress in individuals and cells and analysed the regulating effect of HSF1 gene to HSP70 gene.Our results showed that the expression of HSP70 gene at the transcriptional level was significantly higher(P<0.05)after cold stress in Sanhe Cattle.Short-term cold or heat stress for 0.5 h or 1 h could very significantly up-regulate the HSP70 gene transcriptional expression in cells(P<0.01),but only 42? heat stress for 1 h could significantly increase HSP70 protein expression(P<0.05).HSP70 response patterns to cold and heat stress were different.In addition,HSF1 gene and HSP70 gene both had the same transcriptional up-regulated trend under cell cold stress for 0.5 h or 1 h.However,the response pattern of HSF1 gene and HSP70 gene under short-term heat stress is opposite.Secondly,59 Holstein lactating cows' production data and rectal temperature were collected during summer and autumn to compare the physiological and biochemical changes in different seasons and to analyze the effects of milking,parity and stage of lactation on relatively physiological and biochemical indexes.The results showed that rectal temperature of dairy cattle was very significantly higher than that tested in the optimum temperature(P<0.01),serum ACTH level and COR level were significantly higher than that tested in the optimum temperature(P<0.05 and P<0.01)during heat stress period.And the rectal temperature and COR level of different parities were very significantly different(P<0.01);COR levels of different lactation stages were significantly different(P<0.05)and ACTH levels before and after milking differ significantly(P<0.05)under heat stress.As a conclusion,HSP70 could be selected as one of the important candidate molecular markers to assess cattle response to thermal stress;The rectal temperature,serum ACTH and COR level could be selected as physiological and biochemical indicators for measuring the Holstein cows under heat stress.The combination data of these molecular markers and physiological and biochemical indexes changes,considering the individuals' own conditions,will be more valuable on evaluating thermal stress in cattle and breeding anti-stress breeds.