Sexual reproduction is a tool used to increase genetic diversity amongst species. Trichosphaerium, a genus of amoeba, is understudied compared to other eukaryotic microbes. This genus was described as sexual consisting of two stages, a gamont (gamete-forming) and schizont (spicule-containing) stage. The genetic basis of the sexual gamount stage has never been investigated. In this study, a genetic approach was taken to identify the presence or absence of specific genes present during the gamont stage of Trichosphaerium species. A sex-related gene inventory analysis, containing eleven meiosis-specific genes and 31 fusion genes, was conducted using a custom-made bioinformatics pipeline searching the transcriptomes of three morphotypes including small, medium, and large Trichosphaerium isolates. It was expected for medium and large amoeba to identify several sex-related genes in their transcriptomes, since the cells and nuclei are more likely to fuse when larger compared to when they are smaller. Results support the presence of several meiosis-specific genes in the transcriptomes of medium and large Trichosphaerium isolates, specifically DMC1, MND1, HOP2, MSH5, and MSH4, which are involved in crossover regulation. In conclusion, the identification of meiosis-specific genes in species part of the genus Trichosphaerium supports the claim that the gamont stage of this species is sexual.
