Mitogen-activated protein kinase (MAPK) cascades have a universal cell signaling mechanism in eukaryotes. A typical MAPK signal transduction module comprises three kinds of sequentially phosphorylated protein kinases: MAPK, Mitogen-activated protein kinase kinase (MAPKK), and Mitogen-activated protein kinase kinase kinase (MAPKKK). However, little is known regarding the genes involved in MAPK cascades in Ophiocordyceps sinensis. Nine genes (three MAPK, three MAPKK, and three MAPKKK) were identified in this study. The MAPK, MAPKK, and MAPKKK genes were divided into three subfamilies, according to the phylogenetic analysis. TEY and TGY represented the activation domains of the MAPKs; the corresponding domains in MAPKKs were SDIWS and SDVWS, and those in the MAPKKs were GSVFYWMAPEV and GTPMYMSPEV. Transcription data analysis and quantitative real-time polymerase chain reaction showed that the MAPK cascade was related to the growth of the fruiting body. This is the first study to report a genome-wide identification of the MAPK, MAPKK, and MAPKK gene families in O. sinensis.

丝裂原活化蛋白激酶 (MAPK) 级联在真核生物中具有通用的细胞信号传导机制。一个典型的MAPK信号转导模块包括三种依次磷酸化的蛋白激酶：MAPK、丝裂原活化蛋白激酶激酶（MAPKK）和丝裂原活化蛋白激酶激酶（MAPKKK）。然而，关于在冬虫夏草中参与 MAPK 级联的基因知之甚少。在该研究中鉴定了九个基因（三个 MAPK、三个 MAPKK 和三个 MAPKKK）。根据系统发育分析，MAPK、MAPKK 和 MAPKKK 基因分为三个亚家族。TEY 和 TGY 代表 MAPK 的激活域；MAPKKs 中对应的域为 SDIWS 和 SDVWS，MAPKKs 中对应的域为 GSVFYWMAPEV 和 GTPMYMSPEV。转录数据分析和实时定量聚合酶链反应表明，MAPK级联与子实体的生长有关。这是第一项报告在O. sinensis中对 MAPK、MAPKK 和 MAPKK 基因家族进行全基因组鉴定的研究。