Open AccessA 180 Myr-old female-specific genome region in sturgeon reveals the oldest known vertebrate sex determining system with undifferentiated sex chromosomes
Author(s) -
Heiner Kuhl,
Yann Guiguen,
Christin Höhne,
Eva Kreuz,
Kang Du,
Christophe Klopp,
Céline Lopez-Roques,
Elena Santidrián Yebra-Pimentel,
Mitică Ciorpac,
Jörn Geßner,
Daniela Holostenco,
Wibke Kleiner,
Klaus Kohlmann,
Dunja K. Lamatsch,
Dmitry Prokopov,
Anastasia Bestin,
Emmanuel Bonpunt,
Bastien Debeuf,
Pierrick Haffray,
Romain Morvezen,
Pierre Patrice,
Radu Suciu,
Ron P. Dirks,
Sven Wuertz,
Werner Kloas,
Manfred Schartl,
Matthias Stöck
Publication year - 2021
Publication title -
philosophical transactions - royal society. biological sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.753
H-Index - 272
eISSN - 1471-2970
pISSN - 0962-8436
DOI - 10.1098/rstb.2020.0089
Subject(s) - biology , vertebrate , evolutionary biology , genetics , chromosome , sturgeon , y chromosome , lineage (genetic) , gene , zoology , fishery , fish <actinopterygii>
Several hypotheses explain the prevalence of undifferentiated sex chromosomes in poikilothermic vertebrates. Turnovers change the master sex determination gene, the sex chromosome or the sex determination system (e.g. XY to WZ). Jumping master genes stay main triggers but translocate to other chromosomes. Occasional recombination (e.g. in sex-reversed females) prevents sex chromosome degeneration. Recent research has uncovered conserved heteromorphic or even homomorphic sex chromosomes in several clades of non-avian and non-mammalian vertebrates. Sex determination in sturgeons (Acipenseridae) has been a long-standing basic biological question, linked to economical demands by the caviar-producing aquaculture. Here, we report the discovery of a sex-specific sequence from sterlet ( Acipenser ruthenus ). Using chromosome-scale assemblies and pool-sequencing, we first identified an approximately 16 kb female-specific region. We developed a PCR-genotyping test, yielding female-specific products in six species, spanning the entire phylogeny with the most divergent extant lineages ( A. sturio, A. oxyrinchus versus A. ruthenus, Huso huso ), stemming from an ancient tetraploidization. Similar results were obtained in two octoploid species ( A. gueldenstaedtii, A. baerii ). Conservation of a female-specific sequence for a long period, representing 180 Myr of sturgeon evolution, and across at least one polyploidization event, raises many interesting biological questions. We discuss a conserved undifferentiated sex chromosome system with a ZZ/ZW-mode of sex determination and potential alternatives. This article is part of the theme issue ‘Challenging the paradigm in sex chromosome evolution: empirical and theoretical insights with a focus on vertebrates (Part I)’.