The role of asexuality in mutualism stability

• Grant number: 19/22329-0
• Support Opportunities: Research Grants - Young Investigators Grants
• Start date: February 01, 2023
• End date: January 31, 2028
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Pepijn Wilhelmus Kooij
• Grantee: Pepijn Wilhelmus Kooij
• Host Institution: Instituto de Biociências (IB). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil
• Associated researchers: André Rodrigues ; Mauricio Bacci Junior
• Associated scholarship(s): 24/20805-8 - Ant crop fungus gene expression and transposable elements, BP.MS; 22/14456-5 - The role of asexuality in mutualism stability, BP.JP

Abstract

This project aims to understand the maintenance of mutualistic symbioses. Partners in a mutualism are in a constant conflict, with each gaining the highest benefit when the partner allocates the most resources for the least costs. In mutualisms, sexual reproduction is often controlled by the host via unknown mechanisms. Asexuality occurs frequently among polyploid organisms, such as human fruit crops, arbuscular mycorrhizal fungi and the fungus grown by ants. The fungus-growing ant mutualism is an obligate relationship where each partner is dependent on the other for survival, which parallels human crop domestication. By keeping the fungal symbiont asexual, ants are able to keep it genetically stable, preventing the integration of recombined DNA, and avoiding resource allocation to the sexual organs of the fungus. The aim is to analyze the regulation of asexuality in the fungus grown by ants as influenced by polyploidy and the presence of a third party, a mycovirus, as mycoviruses have been shown to castrate human cultivated fungi. This project will combine high-throughput sequencing tools with in vitro experiments to determine the degree to which genetic diversity in the fungus correlates to efficiency as a mutualist (i.e. the tendency for the fungus not to divert energy into sexual reproduction). It will also analyze the degree to which the ants are able to affect rates and targets of methylation of fungal genes which effectively turns sets of genes on and off. Finally, it will investigate the presence and role of mycoviruses in asexuality. (AU)