Molecular Basis of the Circadian Mechanism

摘要描述了舞毒蛾生殖系统中控制精子释放和成熟的昼夜节律系统。该系统在时间生物学和生理水平上都具有特征，包括其在成人变态过程中的发育时间表。该系统在分子水平上的研究被启动，并导致三个时钟相关（cr）基因的分离，其转录丰度似乎以昼夜节律的方式波动。将确定CR基因是否以及如何参与生物钟机制。在昼夜节律系统的发展过程中，在光或温度重置昼夜节律机制后，以及在破坏节律性的条件下，使用RNAse保护试验和逆转录- pcr来检测三个CR基因丰度的变化。此外，将通过原位杂交研究CR探针对应的mrna的细胞定位。从基因转录到行为，昼夜节律在生物体的各个层次或组织中无处不在。尽管昼夜节律具有根本性的重要性，但驱动昼夜节律的生物钟的分子特性仍然是现代生物学中未解之谜之一。本研究以一种昆虫的简单昼夜节律系统——舞毒蛾雄性生殖道中精子的释放和成熟，来探索生物钟的分子基础。* * *

9407948 Abstract A circadian system was described which controls sperm release and maturation in the make reproductive tract of the gypsy moth. The system was characterized at both the chrono-biological and physiological level, including a time-table for its development during adult metamorphosis. Study of this system at the molecular level was initiated and resulted in the isolation of three clock related(cr) genes whose transcript abundance appear to fluctuate in a circadian fashion. A determination will be made as to whether and how CR genes are involved in the clock mechanism. Changes in the abundance of the three CR genes will be examined during the course of development of circadian system after resetting of the circadian mechanism by light or temperature, and in conditions which disrupt rhythmicity using an RNAse protection assay and reverse transcription-PCR. In addition, cellular localization of mRNAs corresponding to CR probes will be studied by in situ hybridizations. %%% Circadian rhythms are ubiquitous in living organisms at every level or organization, from gene transcription to behavior. Despite the fundamental importance of circadian rhythms, the molecular identity of the clock that drives them remains one of the significant unanswered questions of modern biology. In this study, a simple circadian system of an insect, sperm release and maturation in the male reproductive tract of the gypsy moth, is used to explore the molecular basis of the biological clock. ***