Measuring the effects of carbon catabolite repression on the qa-y gene of Neurospora crassa /

Abstract

Neurospora crassa and Saccharomyces cerevisiae prefer glucose (which is easily metabolized) as a carbon source. These organisms are equipped to utilize alternate carbon sources, but these pathways operate only in the absence of glucose. One form of regulation of these pathways is carbon catabolite repression. This gene regulation is well understood in S. cerevisiae, but much is unknown about this in N. crassa. In order to better understand catabolite repression in N. crassa, I used the quinic acid gene cluster as a model system. Based on earlier data (Asch unpublished) I focused on the qa-y gene. To quantify the repression on the qa-y gene, this study grew a constitutive !1qa-lS strain in three different environments; Vogels only, quinic acid only, or glucose + quinic acid. This study successfully isolated the RNA using a new Sigma protocol and it was essentially pure. The RNA was also successfully reverse transcribed, however all attempts at a peR reaction proved futile, most likely due to degradation of the cDNA. However, this research identified a new method to isolate pure RNA, and ultimately the RNA transcripts from the growing conditions described here will provide information on the effects of carbon catabolite repression on the qa-y permease protein.