Disruption of the Microsomal glutathione S-transferase-like gene reduces life span of Drosophila melanogaster

Microsomal glutathione S-transferase-I (MGST-I) has been thought to be impo rtant for protecting the cell from oxidative damages and/or xenobiotics. We have previously identified the Microsomal glutathione S-transferase-like ( Mgstl) gene, a Drosophila homologue of human MGST-I. To investigate the fun ction of the enzyme using Diosophila as a model system, we examined the exp ression pattern of Mgstl during development, and generated loss-of-function mutants to assess its in-vivo function. Mgstl was expressed in all develop mental stages. It is expressed ubiquitously with the highest expression in the larval fat body, an insect organ thought to be functionally correspondi ng to mammalian liver: while relatively low in the central nervous system. This tissue distribution is consistent with that of MGST-I in humans or Rat s. Mgstl null mutants generated from a P element insertion line showed no o bvious defects in morphology, indicating that it is not essential for the d evelopment. However, their life span was significantly reduced compared to control flies, suggesting that the MGSTL protein is involved in processes s omehow contributing to aging. We found an Mgstl pseudogene, which is appare ntly derived through the reverse transcription of Mgstl mRNA and subsequent integration into the genome. (C) 2000 Elsevier Science B.V. All rights res erved.