Amoebozoans are Secretly but Ancestrally Sexual: Evidence for Sex Genes and Potential Novel Crossover Pathways in Diverse Groups of Amoebae
| Autor: | Yonas I. Tekle, Lydia A. Gorfu, Fiona C. Wood, Laura A. Katz, Mario A Cerón-Romero |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Origin and function of meiosis sexual reproduction Genes Protozoan Genome Asexuality Amoebozoa Evolution Molecular 03 medical and health sciences Meiosis Reproduction Asexual gene inventory life cycle Genetics Amoeba genome Gene Ecology Evolution Behavior and Systematics Polymorphism Genetic biology Synaptonemal Complex biology.organism_classification Sexual reproduction Synaptonemal complex 030104 developmental biology transcriptome Research Article |
| Zdroj: | Genome Biology and Evolution |
| ISSN: | 1759-6653 |
| Popis: | Sex is beneficial in eukaryotes as it can increase genetic diversity, reshuffle their genomes, and purge deleterious mutations. Yet, its evolution remains a mystery. The eukaryotic clade supergroup Amoebozoa encompasses diverse lineages of polymorphic amoeboid forms, including both free-living and parasitic lineages. The group is generally believed to be asexual, though recent studies show that some of its members are implicated in cryptic forms of sexual cycles. In this study, we conduct a comprehensive inventory and analysis of genes involved in meiosis and related processes, in order to investigate the evolutionary history of sex in the clade. We analyzed genomic and transcriptomic data of 39 amoebozoans representing all major subclades of Amoebozoa. Our results show that Amoebozoa possess most of the genes exclusive to meiosis but lack genes encoding synaptonemal complex (SC). The absence of SC genes is discussed in the context of earlier studies that reported ultrastructural evidence of SC in some amoebae. We also find interclade and intrageneric variation in sex gene distribution, indicating diversity in sexual pathways in the group. Particularly, members of Mycetozoa engage in a novel sexual pathway independent of the universally conserved meiosis initiator gene, SPO11. Our findings strongly suggest that not only do amoebozoans possess sex genes in their genomes, but also, based on the transcriptome evidence, the present sex genes are functional. We conclude that Amoebozoa is ancestrally sexual, contrary to the long held belief that most of its members are asexual. Thus, asexuality in Amoebozoa, if confirmed to be present, is a derived-trait that appeared later in their evolution. |
| Databáze: | OpenAIRE |
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