环境温度与clock基因对短趾百灵生殖内分泌及生殖行为节律的影响

发布时间：2018-03-31 16:50

本文选题：环境温度　切入点：生殖内分泌节律　出处：《中央民族大学》2017年硕士论文

【摘要】：以昆虫为食的鸟类必须在一年中昆虫食物最丰富的时间繁殖,因此开始繁殖的时间对这些鸟类非常重要。中高纬度地区的鸟类在长期进化中形成了以光周期信号诱导生殖内分泌进而产生生殖行为的生物学机制。然而许多研究发现鸟类的繁殖时间与春季温度密切相关,温度是通过怎样的生理途径影响了鸟类的繁殖时间?同时,在同一年份中,种群中不同个体也存在繁殖时间的差异,这种差异是否通过遗传基因控制生殖内分泌过程而产生?本研究以内蒙古呼伦贝尔草原上的野生亚洲短趾百灵为例回答了以上两个科学问题。我们监测了 2014年到2016年三年亚洲短趾百灵的生殖内分泌启动情况,同时首次通过实时荧光定量PCR的方法探索了温度对鸟类繁殖信号通路上关键基因表达的影响;本研究还探讨了亚洲短趾百灵繁殖行为与其Clock基因Poly-Q片段长度的关系,得到了以下主要结论:1.2014年春季较高的气温使亚洲短趾百灵的LH、T和E2的峰值水平高于2015年和2016年,分泌高峰期早于2015年和2016年。野外监测和实验室温控实验均表明温度影响亚洲短趾百灵的生殖激素内分泌节律。2.温度影响亚洲短趾百灵下丘脑及垂体生殖内分泌通路上TSHβ、DIO2、DIO3、GnRH、GnRHR、LHGCR和FSHR基因的表达,高温上调TSHβ以及DIO2基因的表达,而抑制DIo3的表达,上调的DIO2促进了GnRH、LH以及FSH基因的表达,最终使LH等生殖激素的分泌高峰期提前出现。以上结果说明温度是通过控制下丘脑垂体关键基因的表达进而影响鸟类生殖内分泌节律和生殖行为节律。3.亚洲短趾百灵Clock poly-Q重复片段与其生殖内分泌及生殖行为节律之间存在联系。Clock基因poly-Q重复片段越短,其LH、T和E2到达峰值的时间、产卵开始和幼鸟出壳的时间越早,而poly-Q重复序列越长,生殖激素到达峰值的时间、产卵开始时间和幼鸟出壳的时间越晚。Clock基因通过调控亚洲短趾百灵的生殖内分泌节律进而影响其繁殖行为节律。Clock基因的多态性是亚洲短趾百灵生殖节律个体间差异的遗传基础。4.在全球气候变化的背景下,亚洲短趾百灵的生殖节律可对年度春季温度变化产生响应,同时种群内部存在可遗传的生殖节律差异,表明该物种具有应对气候变化带来的物候变化的微进化潜能。
[Abstract]:Birds that feed on insects must breed at the most abundant times of the year, so the time to start breeding is very important for these birds.In the long term evolution of birds in the middle and high latitudes, the biological mechanism of reproductive endocrine induced by photoperiod signal and reproductive behavior was formed.However, many studies have found that the breeding time of birds is closely related to the spring temperature. How does temperature affect the breeding time of birds?At the same time, in the same year, different individuals in the population also have different reproductive time. Is this difference produced by genetic control of reproductive endocrine process?In this study, the above two scientific questions were answered by taking wild Asian short toe Bailing on Hulunbeir grassland in Inner Mongolia as an example.We monitored the reproductive endocrine priming of the Asian breast-toed paraxyl from 2014 to 2016, and for the first time explored the effect of temperature on the expression of key genes in the reproductive signaling pathway of birds by real-time fluorescent quantitative PCR.The relationship between the reproductive behavior and the Poly-Q fragment length of Clock gene was also studied. The main conclusions were as follows: 1. The peak levels of Clock T and E2 were higher than those in 2015 and 2016 due to the high temperature in spring 2014.The peak period of secretion was earlier than 2015 and 2016.Field monitoring and laboratory temperature control experiments showed that temperature affected the reproductive hormone endocrine rhythm. 2.Finally, LH and other reproductive hormones secretion peak ahead of time.These results suggest that temperature affects reproductive endocrine rhythm and reproductive behavior rhythm of birds by controlling the expression of key genes in hypothalamus and pituitary.There was a relationship between Clock poly-Q repeats and reproductive endocrine and reproductive behavior rhythms. The shorter the poly-Q repeats of the clock gene, the more the peak time of LHT and E2, and the earlier the spawning began and the young birds came out of shell.The longer the poly-Q repeats, the more time the reproductive hormone reaches its peak.The later the spawning time and the later the emergence time of young birds, the later. Clock gene affects the reproductive behavior rhythm by regulating the reproductive endocrine rhythm of the Asian breast-toed larynx, which is the genetic basis of the individual differences in the reproductive rhythm of the Asian breast-toed Bailing. 4.In the context of global climate change, the reproductive rhythm of the Asian breast-toed Bailing can respond to the annual spring temperature change, and there are genetic differences in the reproductive rhythm within the population.This indicates that the species has the microevolutionary potential to cope with the phenological changes caused by climate change.
【学位授予单位】：中央民族大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q492

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