Project description:Investigation of transcriptomic changes in M.luteus at 12hrs and 24hrs. Differences in fatty acid profiles of M. luteus at exponential and stationary phase is attributed to transcriptional changes of branched amino acid biosynthesis and degradation genes. This study is described by Pereira, J.H., E.B. Goh, J.D. Keasling, H.R. Beller and P.A. Adams in Crystal structure of FabH and factors affecting the distribution of branched fatty acids in Micrococcus luteus, which has been submitted to Acta Crystallographica Section D A 6 microarray study using total RNA recovered from six separate control cultures of Micrococcus luteus NCTC2665 strain with 3 harvested after 12hrs of growth and the other 3 after 24hrs of growth. Each chip measures the expression level of 2,374 ORF based on the draft genome sequence of Micrococcus luteus with ten 60-mer probe pairs (PM/MM) per gene, with 3-fold technical redundancy.
Project description:Objective: Aspergillus flavus aflR, a gene encoding a Zn(II)2Cys6 DNA-binding domain, is an important transcriptional regulator of the aflatoxin biosynthesis gene cluster. Our previous results of GO analysis for the binding sites of AflR in A. flavus suggest that AflR may play an integrative regulatory role. This study aimed to investigate the integrative function of the aflR gene in A. flavus. Design: In this study, we used Aspergillus flavus NRRL3357 as a wild-type strain (WT) and constructed a knockout strain of A. flavus ΔaflR by homologous recombination. Based on the transcriptomics technology, we investigated the metabolic effects of aflR gene on growth, development and toxin synthesis of A. flavus, and discussed the overall regulation mechanism of aflR gene on A. flavus at the transcriptional level. Results: The disruption of aflR severely affected the aflatoxin biosynthetic pathway, resulting in a significant decrease in aflatoxin production. In addition, disrupted strains of the aflR gene produced relatively sparse conidia and a very small number of sclerotia. However, the biosynthesis of cyclopiazonic acid (CPA) was not affected by aflR gene disruption. Transcriptomic analysis of the ΔaflR strain grown on potato dextrose agar (PDA) plates at 0 h, 24 h, and 72 h showed that expression of clustering genes involved in the biosynthesis of aflatoxin was significantly down-regulated. Meanwhile, the ΔaflR strain showed significant expression differences in genes involved in spore germination, sclerotial development, and carbohydrate metabolism compared to the WT strain. Conclusions: The results showed that the A. flavus aflR gene also played a positive role in the growth and development of fungi.
Project description:RNA-seq was used to compare differential gene expressions for Aspergillus flavus wild type strain and ASPES transcription factor deletion strains.The goals of this study are to explore the aflatoxin regulation pathway in A. flavus.
