Genetic basis for coordination of meiosis and sexual structure maturation in Cryptococcus neoformans

Many microbes that cause disease form spores to survive during and between infections. These include the fungus Cryptococcus neoformans, which is the leading cause of fungal meningitis worldwide. This fungus produces spores via sexual reproduction, meaning the genes from two living strains of the fungi combine to create new lives with unique genetics. By diversifying the fungus’s genetics, sexual reproduction in Cryptococcus is considered to accelerate drug resistance. Several processes must be coordinated for Cryptococcus to reproduce sexually. Genetic information recombines through a process called meiosis, the spore-making cell (known as the sexual structure) matures and later spores are produced. Scientists have identified many genes involved in each of these processes. Yet it is not known how these processes are coordinated to ensure the proper sequence of events. Liu, He, Chen et al. studied the physical changes in Cryptococcus cells when they lost certain genes. Two genes, which the researchers named CSA1 and CSA2, were found to regulate the parallel progression of meiosis and maturation of the sexual structure. Both processes need to be complete before spore production begins. Further investigation showed that these genes are important across various strains of infectious Cryptococcus. This research highlights sexual reproduction as a target to stop Cryptococcus forming spores and starting infections. The results also show that these processes change little through evolution within a large group of fungi. The next step will be to see how these systems operate across species and the effect this has on spore production.