| Animals living in non-tropical areas often face seasonal changes in environmental conditions,and as a result,their physiology and behaviour change seasonally and accordingly.The animal's immune system plays an important role in protecting animals from pathogens such as bacteria,fungi and viruses,thus affecting the survival and suitability of animals and reflecting their viability.The striped hamster(Cricetulus barabeniss)is an agricultural rodent that is mainly distributed in northern China.It lives alone and does not hibernate.Its living environment has obvious seasonal changes,so the reproduction of this species has significant seasonal changes.Animals have an energy and resource cost for both immune response and reproduction.The preliminary work of our research team found that the immune function of striped hamsters has seasonal changes,but the mechanism of its changes is still unclear.Since animal reproduction consumes a lot of energy,the trade-offs between immune function and reproduction may be the cause of seasonal changes in the immune function of striped hamsters.We hypothesized that there is a trade-off between the immune function of the striped hamster and the KiSS-1/GPR54 related genes in different seasons.We predict that the striped hamsters have lower immunity at the end of the spring and early autumn of their breeding,while the expression level of KiSS-1 and GPR54 gene was higher than that in winter and summer,and the striped hamster showed enhanced immunity in winter.In order to determine the trade-off between immune function and reproduction of striped hamsters,we measured the concentration of immunoglobulin G(IgG),immunoglobulin M(IgM)in serum,the total number of white blood cells,immune organs(Spleen and thymus),phytohaemagglutinin(PHA)response,serum corticosterone concentration,serum leptin,sex hormones(Estradiol and testosterone),and concentration of each cytokine to reflect immunity.The ability to express KiSS-1,GPR54,GnRH gene expression in the hypothalamus,KiSS-1,GPR54,and GnRH gene expression in male reproductive organs and female reproductive organs was reflected.The main conclusions and results were as follows:1.The immune function of the striped hamster varies with the season,on the 5th day after KLH stimulation,the total number of white blood cells is significantly affected by the season,of which the highest was in winter and the lowest was in autumn;the effect of cell-mediated immune response(PHA response)at 6h,12 h,48h,was significant,and the summer PHA reaction was the most intense;the natural immunity was not affected by the season;the IgG antibody concentration was highest in winter and the IgM antibody concentration was highest in summer;the blood glucose concentration was highest in summer;the corticosterone concentration was the highest in spring;leptin concentration is not affected by seasonal factors,and hemoglobin content,lymphocyte ratio,mean hemoglobin,mean hemoglobin concentration,mean red blood cell volume,mean platelet volume,platelet distribution width,red blood cell count,red blood cell distribution width and hematocrit were significantly affected by the season.2.The expression of KiSS-1 gene in the hypothalamus showed significant seasonal differences in the expression of gene expression related to the reproduction of striped hamsters.The expression of KiSS-1 gene in the fallopian tubes and uterus was highest in autumn,in the fallopian tubes and uterus.The expression level of GnRH was significantly affected by the season.3.The number of lymphocytes and white blood cells in the striped hamsters were significantly positively correlated in spring,summer,autumn and winter.There was a significant positive correlation between fresh ovary ovary weight and thymus fresh weight in spring and summer,and the hypothalamic GPR54 gene in winter.There was a significant negative correlation between the expression level and the number of white blood cells and lymphocytes.The innate immunity was negatively correlated with the expression of GPR54 gene in the hypothalamus.There was a positive correlation between the expression of GPR54 gene in the hypothalamus and the expression of GnRH in the hypothalamus in summer and autumn.There was a significant positive correlation between the expression level of KiSS-1 gene in the hypothalamus and the expression of GnRH.Different immune responses may be related to the physiological state of the body.Striped hamsters exhibit different physiological states in different seasons,indicating that the immune system has seasonal changes.In the experiment,the leptin concentration of striped hamsters did not change significantly,which may be related to the shorter time of experimental treatment.The total number of white blood cells was the highest in winter,supporting the "winter immunity enhancement hypothesis".The amount of expressions of KiSS-1 gene in fallopian tubes and uterus was highest in the autumn,which was consistent with the increase in the expression of reproductive-related genes in the striped hamsters at the peak of the reproductive period in the early autumn.There was a significant negative correlation between the expression of GPR54 gene in the hypothalamus and the number of white blood cells and lymphocytes in winter.The innate immunity was negatively correlated with the expression of GPR54 gene in the hypothalamus,indicating that there is some trade-offs between the immune function of animals and the reproduction of animals.Therefore,different experimental results indicate that the striped hamsters that were treated under different seasons have a trade-off between immune function and KiSS-1/GPR54 reproductive-related genes in different seasons. |
PDF Full Text Request