2005-08-012024-05-16https://scholars.lib.ntu.edu.tw/handle/123456789/666982摘要：生物為了生存，須能因應環境的變化，調整本身的生理狀態。而在自然環境中，光為一重要因子，除了為能量來源，光線的變化也調控自然界中各式生物的生長及發育。在真菌光反應的研究中，Neurospora crassa為主要的研究模式，N. crassa只可感受藍光，藍光除了調控其無性產孢外，還會調控菌絲類胡蘿蔔素之合成，促進原子囊殼的形成，以及子囊殼頸的向光性。在N. crassa的研究中得知，WC-1及WC-2基因為N. crassa光反應主要之調控因子， 2002年發表於”科學”雜誌期刊之兩篇報導，更進一步被証實WC1是其藍光的光接受器，此乃真菌第一個被證實之光反應接受器。隱球菌(Cryptococcus neoformans)，為一伺機性人體病原真菌，具良好的分子生物學研究系統，適合進行真菌致病性、生理及發生學之分子調控機制之探討。研究隱球菌有性生殖之費洛蒙調控機轉中，吾人發現隱球菌有性生殖之雙核菌絲之形成與生長，受光線抑制。在本計畫93年度執行期間，吾人已成功界定隱球菌光反應之光譜範圍，其在可見光譜中亦只可感受藍光。為進一步探討隱球菌光反應之分子調控機制，吾人已於隱球菌中找到N. cras<br> Abstract: In order to survive in nature, all organisms must make appropriate physiological adjustments in response to the environmental changes. Among environmental factors, light has profound effects on lives. Light not only is the major source of energy on earth, and the fluctuation of light also regulates the growth and differentiation of various organisms. In fungi, Neurospora crassa has been the model for studying the molecular mechanism of light response. N. crassa only can sense blue light, and blue light regulates asexual sporulation, induces the production of carotenoids in the vegetative cells, stimulates the development of protoperithecia and the number of perithecia formed, positively attracts the perithecial beaks, and also acts as a signal to entrain the circadian rhythm. In N. crassa, WC1 and WC2 gene have been shown to be the central regulators of the blue light responses. In 2002, two articles published in “Science” demonstrated that WC-1 is the blue light photoreceptor in N. crassa. This is the first photoreceptor identified in fungi. Cryptococcus neoformans is an opportunistic human fungal pathogen with well established molecular biology systems for studying the molecular mechanism of fungal pathogenesis, physiology and differentiation. Studies of the C. neoformans genes involved in the mating process, we observed that production of the dikaryotic filaments during the mating process is influence by light. In studies supported by NSC in 2004, we have determined that C. neoformans also only perceive blue light in the visible light spectrum. To further dissect the molecular mechanism of blue light response in C. neoformans, we have identified the N. crassa WC1 and WC2 homologues in the C. neoformans genome and named the genes CWC1 and CWC2 respectively. Sequence analyses revealed that similar domains are found in Cwc1 and Cwc2, and however, the organization and location are slightly different among these proteins. To dissect their roles in C. neoformans, we have made the cwc1 and cwc2 gene deletion mutants and demonstrated that they both involve in the regulation of photoresponse in C. neoformans. The proposed study is to further dissect the molecular mechanisms regulated by Cwc1 and Cwc2, and also identify the downstream light response pathway in C. neoformans. Specific aims include: functional domains analyses of Cwc1 and Cwc2; determine if Cwc1 is the photoreceptor of C. neoformans; determine the cellular localization of Cwc1 and Cwc2 and if they form complex in vivo; identify other downstream components of light responses in C. neoformans. To the end, we hope to understand the molecular mechanisms of blue light photoresponses in C. neoformans, and finally generate the molecular scheme of blue light signaling in fungi when compared with N. crassa.隱球菌CWC1基因CWC2基因光反應分子機制Cryptococcus neoformansCWC1CWC2light responsemolecular mechanism