Aspergillus niger is among the most important micro-organisms for the industrial production of organic acids and of extracellular enzymes used in the food and feed industry. Until recently, the most common approach for the study of gene function in A. niger was the construction of gene knock-out mutants. Despite its effectiveness, gene knock-out is a time-consuming and laborious method for silencing genes. Furthermore, this method cannot be applied to the study of essential genes. To address this problem, a system for gene knock-down through RNA interference (RNAi) in A. niger was created. As a first step, a destination vector for generation of RNAi clones by recombination reaction was constructed. To test this system, a segment of sequence coding for the xylanolytic regulator XlnR was recombined with the constructed destination vector to yield the corresponding silencing vector. After co-transformation in A. niger, strains were further selected by plate screening on the basis of low xylan-degrading activities. Compared to the wild type, these strains showed lower levels of xlnR transcripts and furthermore two tested genes regulated by XlnR (xyrA and xynB) also presented decreased transcript levels in these co-transformants. Since RNAi has not been applied or described in A. niger, these data show that RNAi constructs effectively work in this fungus. The newly developed system for RNA-mediated gene silencing in A. niger could therefore be efficiently used in functional genomics studies in this fungus.
Full conference title:
9th EUROPEAN CONFERENCE ON FUNGAL GENETICS
- ECFG 9th (2008)