The effect of polyploidy on crop asexuality

• Grant number: 24/22410-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: August 01, 2025
• End date: July 31, 2027
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal Investigator: Pepijn Wilhelmus Kooij
• Grantee: Matheus Custodio Sarkis Cardozo
• Host Institution: Instituto de Biociências (IB). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil
• Associated research grant: 19/22329-0 - The role of asexuality in mutualism stability, AP.JP

Abstract

The first topic of the Project "The role of asexuality in mutualism stability" is the role of polyploidy in the maintenance of an asexual fungal crop. In general, polyploidy can lead to asexuality due to problems in mitosis (e.g., chromosome loss) and meiosis (e.g., unequal division of chromosomes) as well as conflicts in gene expression. Similar to many human-domesticated plant crops, the multinucleate leaf-cutting ant cultivar is polyploid, an unusual condition in mushroom-forming fungi. Polyploidy is often related to crop improvement in plants, by increasing yield and/or the size of fruits, but can also lead to crop asexuality. We hypothesize that if polyploidy influences mushroom production and spore germination of the leaf-cutting ant crop, then reproductive genes should be supressed in or conflicting between the individual genomes and diploid strains should regain the ability to grow basidiomes with viable spores. Haploid strains will be created through protoplasting techniques and recombined in various levels of ploidy.Each strain will then be grown on a mushroom growth inducing medium (Oatmeal Agar) and assessed on basidiome formation and subsequent spore germination. Polyploidy levels will be checked through microsatellite analyses. Furthermore, using laser dissection, single nuclei will be extracted and sequenced using the Oxford Nanopore Technologies MinION, to investigate the genome distribution. This project will contribute to the understanding of the coevolution of this enigmatic mutualism as well as to the evolution of mutualisms in general. It will also provide insights in the evolution of crop polyploidy and asexuality. (AU)