A 180 My-old female-specific genome region in sturgeon reveals the oldest known vertebrate sex determining system with undifferentiated sex chromosomes

Despite decades of cytogenetic and genomic research of dynamic sex chromosome evolution in teleost fishes, multiple sex chromosomes have been largely neglected. In this review, we compiled available data on teleost multiple sex chromosomes, identified major trends in their evolution and suggest further trajectories in their investigation. In a compiled dataset of 440 verified records of fish sex chromosomes, we counted 75 multiple sex chromosome systems with 60 estimated independent origins. We showed that male-heterogametic systems created by Y-autosome fusion predominate and that multiple sex chromosomes are over-represented in the order Perciformes. We documented a striking difference in patterns of differentiation of sex chromosomes between male and female heterogamety and hypothesize that faster W sex chromosome differentiation may constrain sex chromosome turnover in female-heterogametic systems. We also found no significant association between the mechanism of multiple sex chromosome formation and percentage of uni-armed chromosomes in teleost karyotypes. Last but not least, we hypothesized that interaction between fish populations, which differ in their sex chromosomes, can drive the evolution of multiple sex chromosomes in fishes. This underlines the importance of broader inter-population sampling in studies of fish sex chromosomes. 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 II)’.

Section: Introductionmentioning

confidence: 99%

Multiple sex chromosomes in teleost fishes from a cytogenetic perspective: state of the art and future challenges

Sember

Nguyen

Perez

et al. 2021

“…Using chromosome-scale assemblies and pool-sequencing, an approximately 16 kb female-specific sequence from sterlet ( Acipenser ruthenus ) was detected by Kuhl et al . [84]. A polymerase chain reaction-genotyping test, yielding female-specific products in six sturgeon species, spanning the entire phylogeny with the most divergent extant lineages ( Acipenser sturio, Acipenser oxyrinchus versus Acipenser ruthenus, Huso huso ), stemming from an ancient tetraploidization.…”

Section: Overview Of Current Knowledge About Sex Evolution Across the Vertebrate Phylogenymentioning

confidence: 99%

“…Similar results were obtained in two octoploid species ( Acipenser gueldenstaedtii, Acipenser baerii ). Phylogenetic conservation during 180 Myr of sturgeon evolution and across at least one polyploidization event revealed the oldest known vertebrate system with undifferentiated sex chromosomes, based presumably on a ZZ/ZW-mode of sex determination [84].…”

Section: Overview Of Current Knowledge About Sex Evolution Across the Vertebrate Phylogenymentioning

confidence: 99%

A brief review of vertebrate sex evolution with a pledge for integrative research: towards ‘sexomics’

Stöck

Kratochvíl

Kuhl

et al. 2021

Self Cite

Triggers and biological processes controlling male or female gonadal differentiation vary in vertebrates, with sex determination (SD) governed by environmental factors or simple to complex genetic mechanisms that evolved repeatedly and independently in various groups. Here, we review sex evolution across major clades of vertebrates with information on SD, sexual development and reproductive modes. We offer an up-to-date review of divergence times, species diversity, genomic resources, genome size, occurrence and nature of polyploids, SD systems, sex chromosomes, SD genes, dosage compensation and sex-biased gene expression. Advances in sequencing technologies now enable us to study the evolution of SD at broader evolutionary scales, and we now hope to pursue a sexomics integrative research initiative across vertebrates. The vertebrate sexome comprises interdisciplinary and integrated information on sexual differentiation, development and reproduction at all biological levels, from genomes, transcriptomes and proteomes, to the organs involved in sexual and sex-specific processes, including gonads, secondary sex organs and those with transcriptional sex-bias. The sexome also includes ontogenetic and behavioural aspects of sexual differentiation, including malfunction and impairment of SD, sexual differentiation and fertility. Starting from data generated by high-throughput approaches, we encourage others to contribute expertise to building understanding of the sexomes of many key vertebrate species. 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)’.

“…In Part 1, we gather articles around the following major topics: Sex determination without sex chromosomes and/or governed by epigenetics [5,6];Origin of sex-determining genes [7–9];Reasons for differentiation of sex chromosomes and differences in their rates of differentiation [10–14]. …”

mentioning

confidence: 99%

“…Reasons for differentiation of sex chromosomes and differences in their rates of differentiation [10–14].…”

mentioning

confidence: 99%

Preface

Kratochvíl

Stöck

2021

Self Cite

This preface introduces the two parts of a theme issue on vertebrate sex chromosome evolution (title below). We invited and edited 22 articles concerning the following main topics (Part 1): sex determination without sex chromosomes and/or governed by epigenetics; origin of sex-determining genes; reasons for differentiation of sex chromosomes and differences in their rates of differentiation as well as (Part 2): co-option of the same linkage groups into sex chromosomes; is differentiation of sex chromosomes a unidirectional pathway?; consequences of differentiated sex chromosomes; differences in differentiation of sex chromosomes under male versus female heterogamety; evolution of sex chromosomes under hybridization and polyploidy. 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)’.