Diversity of Reptile Sex Chromosome Evolution Revealed by Cytogenetic and Linked-Read Sequencing

Authors

Ze-Xian Zhu, Zhejiang University
Kazumi Matsubara, University of Canberra
Foyez Shams, University of Canberra
Jason Dobry, University of Canberra
Erik Wapstra, University of Tasmania
Tony Gamble, Marquette UniversityFollow
Stephen D. Sarre, University of Canberra
Arthur Georges, University of Canberra
Jennifer A. Marshall Graves, University of Canberra
Qi Zhou, Zhejiang University
Tariq Ezaz, University of Canberra

Document Type

Article

Publication Date

9-2022

Publisher

Kumming Institute of Zoology

Source Publication

Zoological Research

Source ISSN

2095-8137

Original Item ID

DOI: 10.24272/j.issn.2095-8137.2022.127

Abstract

Reptile sex determination is attracting much attention because the great diversity of sex-determination and dosage compensation mechanisms permits us to approach fundamental questions about mechanisms of sex chromosome turnover. Recent studies have made significant progress in better understanding diversity and conservation of reptile sex chromosomes, with however no reptile master sex determination genes identified. Here we describe an integrated genomics and cytogenetics pipeline, combining probes generated from the microdissected sex chromosomes with transcriptome and genome sequencing to explore the sex chromosome diversity in non-model Australian reptiles. We tested our pipeline on a turtle, two species of geckos, and a monitor lizard. Genes identified on sex chromosomes were compared to the chicken genome to identify homologous regions among the four species. We identified candidate sex determining genes within these regions, including conserved vertebrate sex-determining genes pdgfa, pdgfra amh and wt1, and demonstrated their testis or ovary-specific expression. All four species showed gene-by-gene rather than chromosome-wide dosage compensation. Our results imply that reptile sex chromosomes originated by independent acquisition of sex-determining genes on different autosomes, as well as translocations between different ancestral macro- and microchromosomes. We discuss the evolutionary drivers of the slow differentiation and turnover of reptile sex chromosomes.

Comments

Published version. Zoological Research, Vol. 43, No. 5 (September 2022): 719-733. DOI. © 2022 Kunming Institute of Zoology. Used with permission.

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License

Recommended Citation

Zhu, Ze-Xian; Matsubara, Kazumi; Shams, Foyez; Dobry, Jason; Wapstra, Erik; Gamble, Tony; Sarre, Stephen D.; Georges, Arthur; Marshall Graves, Jennifer A.; Zhou, Qi; and Ezaz, Tariq, "Diversity of Reptile Sex Chromosome Evolution Revealed by Cytogenetic and Linked-Read Sequencing" (2022). Biological Sciences Faculty Research and Publications. 935.
https://epublications.marquette.edu/bio_fac/935