The origin and evolution of sex in microbial eukaryotes is a significant challenge to understand. This is compounded by the historical exclusion of microbial eukaryotes from discussions, based on the assumption of their primitiveness and asexuality. Recent research has revealed that microbial eukaryotes, including amoeboid lineages, display evidence of sexual like behaviors. While genomic data has begun to shed light on sexual reproduction in some eukaryotic microbes, the precise mechanisms underlying these processes remain elusive. For example, the well-studied microbes such as the slime mold model organism, Dictyostelium discoideum, and the human pathogen, Entamoeba histolytica, their sexual life cycle still remains poorly understood. A significant obstacle in the study of sexual mechanisms in microbial organisms is the limited knowledge of the diverse and often cryptic nature of their life cycles. In this study, we present compelling genomic and cytological evidence of sexual reproduction characterized by distinct life cycles in various microbial eukaryotes belonging to the supergroup Amoebozoa. Our findings not only provide robust genetic support for the presence of sexual processes in seemingly asexual microbes but also hint at the existence of cryptic sexual cycles that are yet to be fully elucidated.
Unveiling Cryptic Sexual Cycles: Genomic and Cytological Insights into Microbial Eukaryotes from the Supergroup Amoebozoa