Molecular Mechanism And Cellular Immunoregulation In Heat Shock Dairy Cows

This study is aimed at molecular mechanism and cellular immunoregulation in heat shock.dairy cows. The blood indexes at different daily mean temperatures( 37.5°C, 26.5°C, 5.5°C) were analyzed by automatic analyzer of blood. The cell phase and the rate of apoptosis of lymphocytes in peripheral blood of dairy cattle at different daily mean temperature were analyzed by FCM. The abundances of HSP70mRNA, HSFlmRNA, BcI-2mRNA and Bax- α mRNA at different daily mean temperature were analysed by relative quantitative RT-PCR. The single-strand conformation polymorphism (PCR-SSCP) method was used to analyze for SNPs at the 5'-flanking region of the hsp70 gene. BHSP70 protein was successfully expressed in Ecoli. DE3. The results indicated that the four genes mentioned above might be attributed to the apoptosis of lymphocytes. The analysis of SNPs indicated that ac genotype could be acted as a molecular marker for selection of anti-stress dairy cows.1 The heat shock effect on the blood indexes in peripheral blood of dairycowsThe blood indexes at different daily mean temperatures( 37.5 °C, 26.5 °C, 5.5°C) were analyzed by automatic analyzer of blood. The blood indexes included as follows: white blood cell, WBC, lymphocyte, LYMPH, granulocyte, GRAN, mid-cell, MID, LYMPH%, MID%, GRAN%, red blood cell, RBC, hemoglobin, HGB, mean corpuscular volume, MCV, hematocrit, HCT, mean corpuscular hemoglobin, MCH, mean corpuscular hemoglobin concentration, MCHC, red cell distribution width, RDW, platelet count, PLT, mean platelet volume, MPV and platelet-crit, PCT. The results were shown as follows: White blood cell (14.75*10⁹/L) and red blood cell ( 3.85*10¹2 /L) were lowest at 37.5°C, increasing with the temperature drop. MCH and MCHC were higher than that in the control.2 The heat shock effect on the cell phase and the rate of apoptosis oflymphocytes in peripheral blood of dairy cattleThe DNA content, cell phase and the rate of apoptosis of lymphocytes in peripheral blood of dairy cattle at different daily mean temperature were analyzed by FCM. The results were shown as follow: (l)The cell ratios at G₂/M phase were 0.40% at 5.5 °C, which was significantly different from the other two daily mean temperatures(P<0.05). The PI of lymphocytes decreased accompanying with the decrease of the daily mean temperature, the PI (1.10±0.23) at 5.5°Cwere lowest, which was significantly different from those of the other two daily mean temperatures(P<0.05). (2) The rate of apoptosis of lymphocytes was 10.60% at 26.5°C, which was the highest among three groups. The rate of apoptosis of lymphocytes was 2.70% at 5.5°C, which was the lowest and significantly different from the other two groups(P<0.05).3 The Effects of Heat Shock on Expressions of HSP70mRNA, HSFlmRNA, Bcl-2mRNA, Bax- a mRNA and Blood Indexes inlymphocytes in peripheral blood of dairy cowsThe abundances of HSP70mRNA, HSFlmRNA, Bcl-2mRNA and Bax- α mRNA at different daily mean temperature were analysed by relative quantitative RT-PCR. The DNA content, cell phase and the rate of apoptosis of lymphocytes in peripheral blood of dairy cattle at different daily mean temperature were analysed by FCM. The blood indexes were analysed by automatic analyzer of blood. (l)The abundance of HSP70mRNA at 37.5°Cwas which was greatly different from the other two daily mean temperatures(P<0.01). The expression levels of HSP70mRNA and Bcl-2mRNA decreased with the temperature, but HSFlmRNA on the contrary, the abundance of HSFlmRNA at 5.5°C was highest. The Bax-α mRNA abundance was highest at 26.5°C significantly different from the other two daily mean temperatures(P<0.05). The ratio of Bcl-2mRNA/Bax-α mRNA was lowest at 26.5°C and and significantly different from the other two daily mean temperatures(P<0.05). It is concluded that these four genes might be attributed to the apoptosis of lymphocytes.4 Polymorphism of the promoter region of hsp70 gene and its relationship with mRNA level of apoptosis-related genes in lymphocytes in peripheral blood of heat shock dai...