瘦素在黑线仓鼠能量代谢及季节性繁殖中的作用

发布时间：2018-11-11 17:04

【摘要】：小型哺乳动物季节性繁殖与能量代谢水平之间的相互关系一直是近年来动物生态学领域的研究热点。野生哺乳动物在自然环境下如何对季节性繁殖节律进行调控,能量代谢又是如何作用于繁殖节律的,这些依然是尚未解决的问题。瘦素(Leptin)作为机体能量代谢平衡的调定点信号,能将机体各器官及组织脂肪含量的多少相互联系起来,通过下丘脑的瘦素受体发挥作用,协调各器官的能耗及代谢。促性腺激素释脑Gn RH)是影响季节性繁殖的重要因子,在下丘脑分泌并释丘过下丘脑-腺垂体-性腺轴的作用,调控生殖。瘦素对Gn RH在下丘脑处的表达是否有影响?二者表达模式是否相关?瘦素是否参与小型哺乳动物季节性繁殖节律的调控?为探究以上问题,选择山东省的野生黑线仓鼠(Cricetulus barabensis)种群为实验用动物,通过形态测量、静止代谢率的测定、组织学、免疫组织化学和实时荧光定量PCR方法,研究了不同年龄、不同性别黑线仓鼠的生理多样性,检测了Leptin及受体、Gn RH及受体的蛋白表达以及m RNA表达量的季节性规律,探究了科学评价小型哺乳动物能量代谢及繁殖状况的体质指标。实验内容涉及黑线仓鼠生理多样性的性别、年龄和季节差异,体质指标的优化,瘦素及其受体蛋白、Gn RH及其受体蛋白在大脑和下丘脑内的免疫组化定位及相对定量,外周脂肪组织中OB m RNA的相对表达量的季节性动态等。研究结果表明:①Gn RH阳性细胞在雌雄黑线仓鼠下丘脑中的数量均呈显著的季节性变化,一般在高繁殖季节(春秋季)显著高于低繁殖季节(夏冬季),Gn RH受体阳性细胞数量的则相反。结果提示,下丘脑的Gn RH主要调控繁殖功能,而下丘脑的Gn RH受体可能主要参与Gn RH的负反馈调节作用。②Leptin阳性细胞数量在季节间差异显著,且雌雄规律并非完全相同。雄性个体表现为春秋季夏季冬季;雌性个体,表现为秋季春夏季冬季。Leptin受体阳性细胞在季节间差异显著,且雌雄表达规律相近,均表现为高繁殖季节(春秋季)低繁殖季节(夏冬季)。瘦素基因(OB)m RNA在外周脂肪组织中的表达也有显著性的季节差异,且雌雄表达模式相近,即高繁殖季节(春秋季)低繁殖季节(夏冬季)。结果提示,瘦素在中枢神经系统可能作为启动繁殖的一种允许因子而非启动因子而存在,并在一定程度上抑制其繁殖节律。瘦素受体在低繁殖季节的高表达可以介导瘦素作用,进一步抑制机体的繁殖时的能量支出,而增加能量的贮存。③黑线仓鼠静止代谢率表现显著的性别、年龄和季节性差异,其中雄性显著低于雌性,且随年龄和温度的增加而呈降低的趋势。在体质指标方面,肥满度K值和胴体重两个指标则不存在性别间显著性差异;重长比KWL值存在显著的性别间差异,并表现为随年龄的增加而增加,同时雌雄黑线仓鼠的KWL值均表现为季节间差异显著。结果提示,在衡量小型哺乳动物体质状况时,建议使用重长比作为体质指标较为方便有意义。黑线仓鼠作为北方地区农田鼠害优势种,繁殖力强,种群A原因。因此,控制鼠害的综合防控任重而道远。研究结果有助于在分子水平上理解瘦素对黑线仓鼠能量代谢及繁殖水平方面的影响,初步解释黑线仓鼠繁殖的季节性调控与能量代谢的关系,同时有助于更准确的评价小哺乳动物的体质状况,并为揭示黑线仓鼠种群暴发和季节性波动的分子机制提供借鉴。
[Abstract]:The relationship between the seasonal reproduction of small mammals and the level of energy metabolism has been a hot topic in the field of animal ecology in recent years. How wild mammals regulate the seasonal reproduction rhythm in the natural environment, and how energy metabolism works on the reproduction rhythm is still a problem that has not been solved yet. Leptin, as a point-to-point signal of the balance of energy metabolism in the body, can link the levels of fat in various organs and tissues of the body, and coordinate the energy consumption and metabolism of each organ through the role of the leptin receptor in the hypothalamus. Gonadotropin-releasing (Gn RH) is an important factor that affects the seasonal reproduction and regulates the reproduction of the hypothalamus-pituitary-gonad axis in the hypothalamus. Does leptin have an effect on the expression of Gn RH at the hypothalamus? Is the expression pattern of the two related? Is leptin involved in the regulation of the seasonal reproduction rhythm of small mammals? In order to explore the above problems, the wild black-line hamsters (Cricetulus barbadensis) in Shandong Province were selected as experimental animals, and different ages were studied by means of morphometry, measurement of resting metabolic rate, histology, immunohistochemistry and real-time fluorescence quantitative PCR. The physiological diversity of different sex black-line hamsters, the protein expression of Leptin and receptor, Gn RH and the receptor, and the seasonal regulation of the expression of m-RNA were examined, and the physical indexes of energy metabolism and reproduction of small mammals were studied. the experimental contents relate to the sex, the age and the seasonal difference of the physiological diversity of the black line hamsters, the optimization of the physical index, the immunohistochemical localization and relative quantification of the leptin and its receptor protein, Gn RH and its receptor protein in the brain and the hypothalamus, Seasonal dynamics of the relative expression of OB m RNA in peripheral adipose tissue. The results of the study show that the number of positive cells of Gn RH in the hypothalamus of the male and female black-line hamsters has a significant seasonal variation, and the number of positive cells in the Gn RH receptor is in the opposite direction during the high reproduction season (spring fall) significantly higher than that of the low reproduction season (summer winter). It is suggested that the Gn RH in the hypothalamus can regulate and control the reproductive function, while the Gn RH receptor in the hypothalamus may be involved in the negative feedback regulation of Gn RH. The number of Leptin positive cells was significant in the season, and the male and female law was not the same. The male was presented in the spring and autumn and winter in the summer, and the female was in the winter of the spring and summer in the autumn. Leptin receptor positive cells were significantly different in the season, and the male and female expression patterns were similar, all of which were in the low reproduction season (summer and winter) in the high reproduction season (spring fall). The expression of the leptin gene (OB) m RNA in the peripheral adipose tissue is also significant, and the male and female expression patterns are similar, that is, the high propagation season (spring fall) and the low reproduction season (summer winter). The results suggest that leptin may be present in the central nervous system as an allowable factor and a non-priming factor for the initiation and reproduction of the central nervous system, and to a certain extent inhibit its reproduction rhythm. The high expression of the leptin receptor in the low reproduction season can mediate the action of the leptin, further inhibit the energy expenditure during the reproduction of the body, and increase the storage of the energy. Hamster's resting metabolic rate showed a significant gender, age, and seasonal difference in which males were significantly lower than females and decreased with age and temperature. in that aspect of body constitution, there was no significant difference in the sex between the K value and the carcass weight of the body weight, and there was a significant difference in the gender between the weight length and the KWL value, and the KWL value of both male and female black-line hamsters was significantly different from that of the male and female black-line hamsters. The results suggest that the use of the weight-length ratio is more convenient to measure the physical condition of the small mammals. The black-line hamsters are the dominant species in the northern area, and the breeding force is strong and the cause of the population A. Therefore, the comprehensive prevention and control of the control of the mouse harm is a long way to go. The results of the study help to understand the effect of leptin on the energy metabolism and reproductive level of the black-line hamsters at the molecular level, and to explain the relationship between the seasonal regulation and energy metabolism of the black-line hamsters, and to help to evaluate the physical condition of the small mammals more accurately. and provides a reference for revealing the molecular mechanism of the outbreak and the seasonal fluctuation of the black-line hamsters.
【学位授予单位】：曲阜师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S852.21;S814

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