Authors

Discussion

Microsporidia are a group of strict obligate endoparasitic fungi. They are highly successful pathogens that are able to infect a diverse range of hosts, including species of economic significance, and can also cause disease in immunocompromised humans. Trachipleistophora hominis was isolated from HIV/AIDS patients and we use it as a model system to study microsporidia genome and cellular evolution and the molecular basis of host-microsporidia interactions. Here we have investigated the evolution of the parasite and the interplay between host and parasite gene expression using transcriptomics of T. hominis-infected rabbit kidney cells. Highly expressed genes include those involved in growth, replication, defence against oxidative stress, and a large fraction of uncharacterised genes. Host expression suggests a general cellular shutdown upon infection, but ATP, amino sugar and nucleotide sugar production appear enhanced, potentially providing the parasite with substrates it cannot make itself. Expression divergence of duplicated genes, including transporters used to acquire host metabolites, demonstrates ongoing functional diversification during microsporidian evolution. More recently RNASeq time course experiments to follow the infection process are providing more detailed insights into the functional relevance of specific genes during the course of infection and a selection of gene families encoding key metabolite  transporters will be discussed.