| Summary: | 碩士 === 國立陽明大學 === 生命科學系暨基因體科學研究所 === 104 === To survive and reproduce, living organisms must have evolved numerous mechanisms to re-adjust their physiology when encountering adverse situations, for example, drought and famine, which cast severe stress on their physiology. We are interested in these stress-induced physiological changes and have used adult male Caenorhabditis elegans as the model animal to investigate how the stress of food deprivation affects their physiology. Our studies reveal that a short–term starvation (STS) stress at the young age can significantly improve the vitality of the aged male C. elegans, when compared to those unstressed males of the same age. In addition, we found that the stressed aged males have maintained their reproductive activity as do young males, while the un-stressed aged males lose the activity quickly and are no longer reproductive at the same ages examined. The short term starvation stress, particularly at young age, can preserve the number and quality of sperms in the aged male worms, as evidenced by the significantly increased activity of spermatogenesis and the enhanced expression of semen and sperm factors to maintain sperm ability to fertilize. Spermatogenesis involves germ cell proliferation and mitotic/ meiotic division and requires many cell regulators in the surveillance mechanism. We have examined the role of numerous factors, reportedly important for spermatogenesis, by using the reverse genetic strategy to study the spermatogenesis activity in their mutant strains upon starvation treatment. Our results show that the mutant strains defected in APC/C (Anaphase Promoting Complex/ Cyclosome) function fail to respond to starvation stress to enhance their spermatogenesis as found in the wild-type N2 worms, suggesting that the mechanism underlying the starvation-induced spermatogenesis involves the action of the APC/C complex, a conserved ubiquitin-protein ligase E3 complex that functions during cell cycle transition and is crucial in meiosis.
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