Sex in protists: A new perspective on the reproduction mechanisms of trypanosomatids

Abstract

The Protist kingdom individuals are the most ancestral representatives of eukaryotes. They have inhabited Earth since ancient times and are currently found in the most diverse environments presenting a great heterogeneity of life forms. The unicellular and multicellular algae, photosynthetic and heterotrophic organisms, as well as free-living and pathogenic protozoa represents the protist group. The evolution of sex is directly associated with the origin of eukaryotes being protists the earliest protagonists of sexual reproduction on earth. In eukaryotes, the recombination through genetic exchange is a ubiquitous mechanism that can be stimulated by DNA damage. Scientific evidences support the hypothesis that reactive oxygen species (ROS) induced DNA damage can promote sexual recombination in eukaryotes which might have been a decisive factor for the origin of sex. The fact that some recombination enzymes also participate in meiotic sex in modern eukaryotes reinforces the idea that sexual reproduction emerged as consequence of specific mechanisms to cope with mutations and alterations in genetic material. In this review we will discuss about origin of sex and different strategies of evolve sexual reproduction in some protists such that cause human diseases like malaria, toxoplasmosis, sleeping sickness, Chagas disease, and leishmaniasis.

Let's talk about sex: Why reproductive systems matter for understanding algae

“…However, for most eukaryotes, sex is not always tied to a reproductive process (see Beukeboom & Perrin, 2014). We are accumulating evidence for the occurrence of sex across taxa with ever‐expanding genomic capabilities, but these observations are nevertheless indirect, such as the identification of functional meiotic genes (Bhattacharya et al., 2013; de Silva & Machado, 2022; see also Beukeboom & Perrin, 2014) or the calculation of population genetic summary statistics (Duminil et al., 2007; Ellegren & Galtier, 2016; Tibayrenc & Ayala, 1991). Our knowledge of sex in nature remains rudimentary outside of taxa of economic, ecological, or epidemiological importance and ease of laboratory‐based cultivation (Aanen et al., 2016).…”