Trichophyton rubrum is a dominating superficial dermatophyte, whose conidial germination is corre- lated to pathopoiesis and a highly important developmental process. To investigate the changes of physiology, biochemistry and cytology during the germination, we selected 3364 function identified ESTs from T. rubrum cDNA library to construct cDNA microarrays, and compared the gene expression levels of conidia and germinating phase. Data analysis indicated that 335 genes were up-regulated during the germination, which mainly encoded translated, modified proteins and structural proteins. The constituents of cell wall and cell membrane were synthetized abundantly, suggesting that they are the foundation of cell morphogenesis. The ingredients of the two-component signal transduction sys- tem were up-regulated, presuming that they were important for the conidial germination. Genes of various metabolic pathways were expressed prosperously, especially the genes that participated in glycolysis and oxidative phosphorylation were up-regulated on the whole, demonstrating that in the environment with sufficient oxygen and glucose, conidia obtained energy through aerobic respiration. This paper provides important clues which are helpful to understanding the changes in gene expres- sion, signal conduction and metabolism characteristics during T. rubrum conidial germination, and possess significant meaning to the study of other superficial dermatophytes.
YANG Li1,2, WANG LingLing2, PENG JunPing2, YU Lu2, LIU Tao2, LENG WenChuan2, YANG Jian2, CHEN LiHong2 , ZHANG WenLiang2, ZHANG Qian2, QI YiPeng1 & JIN Qi1,2,3 1 College of Life Sciences, Wuhan University, Wuhan 430072, China
Trichophyton rubrum (T. rubrum) is the most common of the superficial fungi. In an effort to better understand the genetic and biochemical makeup of T. rubrum, we generated cDNA libraries from 3 growth stages and used these to isolate 4002 unique expressed sequence tags (ESTs). Sequence comparisons with the Genbank database allowed 1226 of the ESTs to be assigned putative functions or matched with homologs from other organisms. Of the remaining ESTs, 989 were only weakly similar to known sequences and 1787 had no identifiable functions, suggesting that they represent novel genes. We further analyzed the presence of several im-portant genes involved in the growth, metabolism, signal transduction, pathogenesis and drug resistance in T. rubrum. This information was used to newly elucidate important metabolic path-ways in T. rubrum. Taken together, our results should form the molecular basis for continued re-search on the physiological processes and pathogenic mechanisms of T. rubrum, and may lead to a better understanding of fungal drug resistance and identification of new drug targets.
