Dhiman, A. | Search bioRxiv

bioRxiv2018

PBRM1 regulates stress response in epithelial cells

Polybromo1 (PBRM1) is a chromatin remodeler subunit highly mutated in cancer, particularly renal clear cell carcinoma. PBRM1 is a member of the SWI/SNF subcomplex, PBAF (PBRM1-Brg1/Brm Associated Factors) and is characterized by six tandem bromodomains. Here we establish a role for PBRM1 in epithelial cell maintenance through the expression of genes involved in cell adhesion, metabolism, stress response, and apoptosis. In support of a general role for PBRM1 in stress response and apoptosis, we observe that loss of PBRM1 results in an increase in reactive oxygen species generation and a decrease in cellular viability under stress conditions. We find that loss of PBRM1 promotes cell growth under favorable conditions but is required for cell survival under conditions of cellular stress.

cell biology↗

bioRxiv2017

Pathogen Dependent Phenotypic But No Genetic Correlation Between Sexual Activity And Immunity In Male Drosophila melanogaster Subjected To Differential Sexual Selection

The theory of trade-off suggest that limited resources should lead to trade-off in resource intensive traits such as immunity related and sexually selected traits in males. Alternatively, sexual exaggerations can also act as an honest indicator of underlying immunocompetence, leading to positive correlations between these traits. Several studies have addressed this question using experimental evolution. However, they have rarely used ecologically relevant pathogens and fitness measurement (e.g., measuring post-infection survivorship) to find correlations between sexual selection and immunity. Here we attempt to address this caveat by evolving populations of Drosophila melanogaster under differential sexual selection. After more than hundred generations, we infected virgin and mated males from each population with three pathogenic bacteria: Pseudomonas entomophila (Pe), Staphylococcus succinus (Ss) and Providentia rettgeri (Pr). Fitness was measured as either post-infection survivorship (Pe and Ss) or bacterial clearance ability (Pr). Contrary to expectations, sexual selection had no evolutionary effect on male fitness against any of the pathogens. Moreover, mating had a beneficial effect against Pe and Pr, but no effect against Ss, suggesting pathogen specific phenotypic correlations between mating and immunity. Following these results, we discuss the significance of using ecologically relevant pathogens and quantifying host fitness while studying sexual selection-immunity correlations.

evolutionary biology↗