Eurasian brine shrimp (genus Artemia) have closely related sexual and asexual lineages of parthenogenetic females, which produce rare males at low frequencies. Although they are known to have ZW chromosomes, these are not well characterized, and it is unclear whether they are shared across the clade. Furthermore, the underlying genetic architecture of the transmission of asexuality, which can occur when rare males mate with closely related sexual females, is not well understood. We produced a chromosome-level assembly for the sexual Eurasian species Artemia sinica and characterized in detail the pair of sex chromosomes of this species. We combined this new assembly with short-read genomic data for the sexual species Artemia sp. Kazakhstan and several asexual lineages of Artemia parthenogenetica, allowing us to perform an in-depth characterization of sex-chromosome evolution across the genus. We identified a small differentiated region of the ZW pair that is shared by all sexual and asexual lineages, supporting the shared ancestry of the sex chromosomes. We also inferred that recombination suppression has spread to larger sections of the chromosome independently in the American and Eurasian lineages. Finally, we took advantage of a rare male, which we backcrossed to sexual females, to explore the genetic basis of asexuality. Our results suggest that parthenogenesis is likely partly controlled by a locus on the Z chromosome, highlighting the interplay between sex determination and asexuality.
This work was supported by the European Research Council under the European Union’s Horizon 2020 research and innovation program (grant agreement no. 715257) and by the Austrian Science Foundation (FWF SFB F88-10). We thank the Vicoso group for comments on the manuscript and the ISTA Scientific computing team and the Vienna Biocenter Sequencing facility for technical support.
Elkrewi MN, Khauratovich U, Toups MA, et al. ZW sex-chromosome evolution and contagious parthenogenesis in Artemia brine shrimp. Genetics. 2022;222(2). doi:10.1093/genetics/iyac123
Elkrewi, M. N., Khauratovich, U., Toups, M. A., Bett, V. K., Mrnjavac, A., Macon, A., … Vicoso, B. (2022). ZW sex-chromosome evolution and contagious parthenogenesis in Artemia brine shrimp. Genetics. Oxford University Press. https://doi.org/10.1093/genetics/iyac123
Elkrewi, Marwan N, Uladzislava Khauratovich, Melissa A Toups, Vincent K Bett, Andrea Mrnjavac, Ariana Macon, Christelle Fraisse, et al. “ZW Sex-Chromosome Evolution and Contagious Parthenogenesis in Artemia Brine Shrimp.” Genetics. Oxford University Press, 2022. https://doi.org/10.1093/genetics/iyac123.
M. N. Elkrewi et al., “ZW sex-chromosome evolution and contagious parthenogenesis in Artemia brine shrimp,” Genetics, vol. 222, no. 2. Oxford University Press, 2022.
Elkrewi MN, Khauratovich U, Toups MA, Bett VK, Mrnjavac A, Macon A, Fraisse C, Sax L, Huylmans AK, Hontoria F, Vicoso B. 2022. ZW sex-chromosome evolution and contagious parthenogenesis in Artemia brine shrimp. Genetics. 222(2), iyac123.
Elkrewi, Marwan N., et al. “ZW Sex-Chromosome Evolution and Contagious Parthenogenesis in Artemia Brine Shrimp.” Genetics, vol. 222, no. 2, iyac123, Oxford University Press, 2022, doi:10.1093/genetics/iyac123.
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