Regulatory mechanism for selective expression of silent paralogous genes in filamentous fungi

2013 Fiscal Year Final Research Report

• Project/Area Number: 23658065
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Applied microbiology
• Research Institution: Tohoku University
• Principal Investigator: GOMI Katsuya 東北大学, (連合)農学研究科(研究院), 教授 (60302197)
• Project Period (FY): 2011 – 2012
• Keywords: 糸状菌 / 遺伝子クラスター / トランスポーター / 転写因子 / ホモログ遺伝子 / アミラーゼ生産 / マルトース資化

Research Abstract

Two paralogous gene clusters that are deduced to be involved in maltose assimilation exist in the genome of Aspergillus oryzae. These clusters are both consisting of three genes that each encodes a transporter, alpha-glucosidase, and a transcription factor, respectively, and one of them is functional but the other seems to be transcptionally silent. However, interestingly, these silent genes are induced to be transcribed when the functional genes are disrupted. The paralogous transporter gene was proved to encode a functional maltose transporter by complementation experiment. Double disruption of the transporter genes did not result in the defect in growth on maltose medium and also in alpha-amylase production, probably due to a significantly low transcription level of the pralogous transporter gene.