Sexual reproduction is a tool used to increase genetic diversity amongst species. Previous studies of small eukaryotic microbe life cycles, including Amoebozoa, have assumed these organisms to reproduce asexually. Interestingly, studying the lifecycle of Cochliopodium, a genus of amoeba, and other microbes have exhibited parts of the complete sexual cycle, described as parasexual reproduction. Cochliopodium is of interest due to its unique reproductive cycle containing parts of conventional stages including cellular fusion, karyogamy, and fission. A previous study identified several cytoskeleton intermediate filament proteins in the genomes of some amoeba species, supporting the hypothesis of Amoebozoa and Opisthokonta exhibiting close evolutionary relationship. A gene inventory analysis was conducted using a custom-made bioinformatics pipeline searching the transcriptomes of amoeba species Cochliopodium minus and an undescribed species UK-YT1, in different stages of their life cycles for the sex genes. Our results support the presence of sex genes in the transcriptomes of C. minus and UK-YT1; however, they do not support the presence of intermediate filament proteins in these particular amoebae, indicating a potential difference of the distribution and evolution of these genes in Amoebozoa. In conclusion, the identification of sex genes in these amoebae supports previous claims that Amoebozoa are ancestrally sexual.
