Genome analysis and polar tube firing dynamics of mosquito-infecting microsporidia

•Review of genome sequences for two microsporidian species that infect mosquitoes.•Largest genome size reported to date for microsporidia, which characteristically have small genomes.•Video of the dynamics of polar tube firing in mosquito-infecting microsporidia.

Microsporidia are highly divergent fungi that are obligate intracellular pathogens of a wide range of host organisms. Here we review recent findings from the genome sequences of mosquito-infecting microsporidian species Edhazardia aedis and Vavraia culicis, which show large differences in genome size, although similar numbers of predicted genes. We also show a video of E. aedis polar tube firing, which is the dramatic mechanism used by microsporidia to deliver the germ cell (sporoplasm) into the host cell to initiate intracellular infection.