有性生殖在病原性念珠菌的宿主环境适应中起重要作用，也是致病性和耐药性快速进化的推动力。Rab家族成员Vps21是一种单体GTP酶，是囊泡运输的重要调节因子，参与内体成熟的过程并且对白念珠菌环境适应和菌丝的发育具有调控作用。我们的初步实验数据发现，Vps21在白念珠菌交配态opaque细胞的形成和有性生殖过程中扮演着重要角色。本项目将通过研究Vps21在白念珠菌opaque细胞形成以及有性生殖发生过程中的作用，探索囊泡运输途径在有性生殖过程中的功能，揭示其分子调控机理；并结合Ste11-Hst7-Cek1/2介导的MAPK信息素响应和pH应答途径，解析白念珠菌在对环境因素应答时，多条信号途径如何协同调控有性生殖过程。本项目从一个新角度认识单体GTP酶Vps21及相关信号途径与有性生殖之间关系，将提升我们对白念珠菌有性生殖和致病性形成的认识，为寻找抗念珠菌新途径提供思路。

Sexual reproduction plays a critical role in the adaptation of Candida spp. pathogens to fluctuating environments, and promotes the evolution of pathogenesis and drug resistance. Vps21, a monomeric small GTPases of the Rab family, which is required for endosomal trafficking. It regulates the process of endosome maturation, stress resistance, and hyphal growth in Candida alibcans. Our preliminary data demonstrates that Vps21 functions in the regulation of opaque cell formation and sexual reproduction. In this study, we are going to focus on the regulatory mechanism of the Vps21 in the process of opaque formation and sexual reproduction in C. albicans. We will investigate the function and mechanism of endosomal trafficking pathway in the regulation of sexual reproduction and analyze how the cells coodinate the Rim101-mediated pH-responding signaling and Ste11-Hst7-Cek1/2-mediated pheromone-responding pathway to respond to environmental changes (such as pH) and thus to initiate the sexual reproduction process. This study will shed new lights on the regulatory mechanism of C.albicans sexual reproduction upon environmental pH changes from a novel angle of view. The improvement of our understanding of the sexual reproduction and pathogenicity of C.albicans will also provide new strategies for the control of fungal infections.