SUMMARY: Researchers compared the genomes of two ciliates: one known to have sex, and another that has not been observed to have sex under laboratory conditions. Genes for meiosis were found in both classes of ciliates. Also, structures such as the micronuclei and macronuclei indicate that perhaps the ciliates were engaging in secretive sex. Some interesting ways eukaryotic cells have sex include: automixis, diplomixis, and parasexuality.
LESSON COMMENTS: This article will challenge students’ ideas of meiosis and sexual reproduction in eukaryotes. Topics covered include: meiosis, mechanisms of meiosis, differences in nuclei of humans versus protozoa, what enzymes the meiosis genes code for and the function of those enzymes, haploid, diploid, polyploid, various types of sexual cycles (automixis, diplomixis, and parasexuality), and the evolution of these various types of sexual reproduction.
Dunthorn, M., Zufall, R. A., Chi, J., Paszkiewicz, K., Moore, K., & Mahé, F. (2017). Meiotic Genes in Colpodean Ciliates Support Secretive Sexuality. Genome biology and evolution, 9(6), 1781-1787.