Stem cells' microenvironment
GSLs are a type of glycolipid. They are found in the cell membranes of organisms from bacteria to humans, and are the major glycans of the vertebrate brain. They play roles in membrane structure, host–pathogen interactions, cell–cell recognition and modulation of membrane protein function. The project 'The role of glycosphingolipids in development' (GSL IN DEVELOPMENT) found that one of the enzymes involved in the synthesis of core GSLs was important in the biology of the stem cell niche of the testis in Drosophila melanogaster males. These males presented an abnormal maintenance of the stem cells forming their testis niche. The homeostasis of self-renewing tissues is dependent on the regulation of stem cells by their microenvironment. Understanding how environmental and physiological changes regulate the activity of stem cells is a key issue. Thus, the scope of the project was redirected to the study of the impact of such changes on the stem cells in the Drosophila testis.Researchers have been able to describe quantitatively the variation and the dynamic of the activity of the testis stem cell niche in various environmental and physiological conditions. During this characterisation, they discovered that Wolbachia pipientis (WP), an alphaproteobacteria, which is a natural endosymbiont of D melanogaster in the wild, affected significantly the testis homeostasis. By analysing the influence of these bacteria on the homeostasis of the testis in wild-type males, they demonstrated that WP likely affected the stem cells' maintenance. In addition, the infection by the bacteria was associated with a better maintenance of somatic and germinal stem cells during the ageing of the males. These results suggest that WP infection might promote a better survival of the infected males. The manuscript with these results has been submitted for publication. This work unveiled a previously unknown impact of the WP endosymbiont on Drosophila testis niche. WP is a common endosymbiont in many different arthropod and worm species on the planet. Recently, Wolbachia has become famous for conferring a resistance of its host to many different parasites and viruses, among which are those responsible for malaria and the lethal Dengue fever. Project work will hopefully inspire new research to understand how bacteria manipulate the immune system of their hosts, and how to impair their ability to spread lethal human pandemic diseases.
Keywords
Glycosphingolipid, Wolbachia pipientis, Drosophila testis, endosymbiont, stem cell
