Peng Han, Zhang Yi-Lu, Ying Sheng-Hua, Feng Ming-Guang
Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
J Fungi (Basel). 2022 May 25;8(6):558. doi: 10.3390/jof8060558.
FRQ (frequency protein), FRH (FRQ-interacting RNA helicase), and WC1 and WC2 (white collar proteins) are major clock elements that govern the circadian rhythm in . However, deletion of is lethal for the viability of , making it elusive whether FRH is essential or nonessential for the circadian rhythm. This needs clarification in a fungus where deletion is not lethal. Here, the nuclear FRH ortholog proved nonessential for the circadian rhythm of . The nucleocytoplasmic shuttling of FRQ, WC1, and WC2 orthologs was light-dependent. Yeast two-hybrid assay validated interactions of FRQ with FRH and WC1 instead of FRH with WC1 and WC2 or FRQ with WC2. The circadian rhythm well, shown as conidiation rings of tint and dark in 15 d-old plate cultures grown at 25 °C in a light/dark cycle of 12:12, was abolished in the absence of or , partially disturbed in the absence of , but unaffected in the absence of . These results indicate a requirement of either FRQ or WC1 instead of FRH for the fungal circadian rhythm. Further analyses of and mutants revealed the dispensable and the limited roles of FRQ and FRH in the insect-pathogenic lifecycle of , respectively.
FRQ（频率蛋白）、FRH（与FRQ相互作用的RNA解旋酶）以及WC1和WC2（白领蛋白）是控制[具体生物]昼夜节律的主要生物钟元件。然而，缺失[某种物质]对[具体生物]的生存能力是致命的，这使得FRH对于昼夜节律是必不可少还是并非必需难以确定。这需要在一种缺失[该物质]不致死的真菌中加以阐明。在此，核内FRH直系同源物被证明对于[具体生物]的昼夜节律并非必需。FRQ、WC1和WC2直系同源物的核质穿梭是光依赖性的。酵母双杂交试验验证了FRQ与FRH以及WC1之间的相互作用，而非FRH与WC1和WC2之间或FRQ与WC2之间的相互作用。在25℃下以12:12的光/暗周期培养15天的平板培养物中，以浅色和深色分生孢子环表现出的良好昼夜节律，在缺失[某种物质]或[另一种物质]时被消除，在缺失[又一种物质]时部分受到干扰，但在缺失[再一种物质]时未受影响。这些结果表明，真菌昼夜节律需要FRQ或WC1而非FRH。对[具体生物]和[具体生物]突变体的进一步分析分别揭示了FRQ和FRH在[具体生物]昆虫致病生命周期中可有可无和有限的作用。
