scholarly journals Complex Structure of Lasiopodomys mandarinus vinogradovi Sex Chromosomes, Sex Determination, and Intraspecific Autosomal Polymorphism

Genes ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 374 ◽  
Author(s):  
Svetlana A. Romanenko ◽  
Antonina V. Smorkatcheva ◽  
Yulia M. Kovalskaya ◽  
Dmitry Yu. Prokopov ◽  
Natalya A. Lemskaya ◽  
...  
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
De Novo ◽  
Complex Structure ◽  
X Chromosomes ◽  
Single Chromosome ◽  
Determination System ◽  
Sex Determination System ◽  
Mandarin Vole

The mandarin vole, Lasiopodomys mandarinus, is one of the most intriguing species among mammals with non-XX/XY sex chromosome system. It combines polymorphism in diploid chromosome numbers, variation in the morphology of autosomes, heteromorphism of X chromosomes, and several sex chromosome systems the origin of which remains unexplained. Here we elucidate the sex determination system in Lasiopodomys mandarinus vinogradovi using extensive karyotyping, crossbreeding experiments, molecular cytogenetic methods, and single chromosome DNA sequencing. Among 205 karyotyped voles, one male and three female combinations of sex chromosomes were revealed. The chromosome segregation pattern and karyomorph-related reproductive performances suggested an aberrant sex determination with almost half of the females carrying neo-X/neo-Y combination. The comparative chromosome painting strongly supported this proposition and revealed the mandarin vole sex chromosome systems originated due to at least two de novo autosomal translocations onto the ancestral X chromosome. The polymorphism in autosome 2 was not related to sex chromosome variability and was proved to result from pericentric inversions. Sequencing of microdissection derived of sex chromosomes allowed the determination of the coordinates for syntenic regions but did not reveal any Y-specific sequences. Several possible sex determination mechanisms as well as interpopulation karyological differences are discussed.

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

2021 ◽  
Vol 376 (1832) ◽  
pp. 20200089
Author(s):  
Heiner Kuhl ◽  
Yann Guiguen ◽  
Christin Höhne ◽  
Eva Kreuz ◽  
Kang Du ◽  
...  
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Specific Sequence ◽  
Genome Region ◽  
Acipenser Ruthenus ◽  
Determination System ◽  
Sex Determination System ◽  
Female Specific ◽  
Polyploidization Event

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)’.

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

2020 ◽  
Author(s):  
Heiner Kuhl ◽  
Yann Guiguen ◽  
Christin Höhne ◽  
Eva Kreuz ◽  
Kang Du ◽  
...  
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Specific Sequence ◽  
Genome Region ◽  
Acipenser Ruthenus ◽  
Determination System ◽  
Sex Determination System ◽  
Female Specific ◽  
Polyploidization Event

SummarySeveral 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 a ~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 vs. 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 My 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.

scholarly journals Sex chromosome evolution, heterochiasmy and physiological QTL in the salmonid Brook Charr Salvelinus fontinalis

2017 ◽  
Author(s):  
Ben J. G. Sutherland ◽  
Ciro Rico ◽  
Céline Audet ◽  
Louis Bernatchez
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Genetic Architecture ◽  
Salvelinus Fontinalis ◽  
Sex Chromosome ◽  
Brook Charr ◽  
Determination System ◽  
Males And Females ◽  
Sex Determination System ◽  
Sex Determination Mechanisms

ABSTRACTWhole genome duplication can have large impacts on genome evolution, and much remains unknown about these impacts. This includes the mechanisms of coping with a duplicated sex determination system and whether this has an impact on increasing the diversity of sex determination mechanisms. Other impacts include sexual conflict, where alleles having different optimums in each sex can result in sequestration of genes into non-recombining sex chromosomes. Sex chromosome development itself may involve sex-specific recombination rate (i.e. heterochiasmy), which is also poorly understood. Family Salmonidae is a model system for these phenomena, having undergone autotetraploidization and subsequent rediploidization in most of the genome at the base of the lineage. The salmonid master sex determining gene is known, and many species have non-homologous sex chromosomes, putatively due to transposition of this gene. In this study, we identify the sex chromosome of Brook Charr Salvelinus fontinalis and compare sex chromosome identities across the lineage (eight species, four genera). Although non-homology is frequent, homologous sex chromosomes and other consistencies are present in distantly related species, indicating probable convergence on specific sex and neo-sex chromosomes. We also characterize strong heterochiasmy with 2.7-fold more crossovers in maternal than paternal haplotypes with paternal crossovers biased to chromosome ends. When considering only rediploidized chromosomes, the overall heterochiasmy trend remains, although with only 1.9-fold more recombination in the female than the male. Y chromosome crossovers are restricted to a single end of the chromosome, and this chromosome contains a large interspecific inversion, although its status between males and females remains unknown. Finally, we identify QTL for 21 unique growth, reproductive and stress-related phenotypes to improve knowledge of the genetic architecture of these traits important to aquaculture and evolution.

scholarly journals ZZ/ZW Sex Determination with Multiple Neo-Sex Chromosomes is Common in Madagascan Chameleons of the Genus Furcifer (Reptilia: Chamaeleonidae)

Genes ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1020 ◽  
Author(s):  
Rovatsos ◽  
Altmanová ◽  
Augstenová ◽  
Mazzoleni ◽  
Velenský ◽  
...  
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Comparative Genomic ◽  
Telomeric Sequences ◽  
Female Heterogamety ◽  
Chromosomal Variability ◽  
Determination System ◽  
Hybridization In Situ ◽  
Sex Determination System

Chameleons are well-known, highly distinctive lizards characterized by unique morphological and physiological traits, but their karyotypes and sex determination system have remained poorly studied. We studied karyotypes in six species of Madagascan chameleons of the genus Furcifer by classical (conventional stain, C-banding) and molecular (comparative genomic hybridization, in situ hybridization with rDNA, microsatellite, and telomeric sequences) cytogenetic approaches. In contrast to most sauropsid lineages, the chameleons of the genus Furcifer show chromosomal variability even among closely related species, with diploid chromosome numbers varying from 2n = 22 to 2n = 28. We identified female heterogamety with cytogenetically distinct Z and W sex chromosomes in all studied species. Notably, multiple neo-sex chromosomes in the form Z1Z1Z2Z2/Z1Z2W were uncovered in four species of the genus (F. bifidus, F. verrucosus, F. willsii, and previously studied F. pardalis). Phylogenetic distribution and morphology of sex chromosomes suggest that multiple sex chromosomes, which are generally very rare among vertebrates with female heterogamety, possibly evolved several times within the genus Furcifer. Although acrodontan lizards (chameleons and dragon lizards) demonstrate otherwise notable variability in sex determination, it seems that female heterogamety with differentiated sex chromosomes remained stable in the chameleons of the genus Furcifer for about 30 million years.

scholarly journals Sex-linked markers and microsatellite locus duplication in the cichlid species Oreochromis tanganicae

2008 ◽  
Vol 4 (6) ◽  
pp. 700-703 ◽  
Author(s):  
Avner Cnaani ◽  
Thomas D Kocher
Keyword(s):  
Sex Determination ◽  
Dna Markers ◽  
Microsatellite Dna ◽  
Sex Chromosome ◽  
Inheritance Pattern ◽  
Cichlid Species ◽  
Microsatellite Dna Markers ◽  
Determination System ◽  
Group 3 ◽  
Sex Determination System

Cichlid species of the genus Oreochromis vary in their genetic sex-determination systems. In this study, we used microsatellite DNA markers to characterize the sex-determination system in Oreochromis tanganicae . Markers on linkage group 3 were associated with phenotypic sex, with an inheritance pattern typical of a female heterogametic species (WZ–ZZ). Further, locus duplication was observed for two separate microsatellite markers on the sex chromosome. These results further advance our understanding of the rapidly evolving sex-determination systems among these closely related tilapia species.

scholarly journals Sex-determination and sex chromosomes are shared across the radiation of dioecious Nepenthes pitcher plants

2017 ◽  
Author(s):  
Mathias Scharmann ◽  
T. Ulmar Grafe ◽  
Faizah Metali ◽  
Alex Widmer
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
High Throughput Sequencing ◽  
Silene Latifolia ◽  
Wild Populations ◽  
Sequencing Data ◽  
Pitcher Plants ◽  
Determination System ◽  
Sex Determination System ◽  
Male Specific

AbstractPlants with separate sexes (dioecy) represent a minority but dioecy has evolved multiple times independently in plants. Our understanding of sex determination systems in plants and of the ecological factors and molecular changes associated with the evolution of dioecy remain limited. Here, we study the sex-determination system in dioecious plants that lack heteromorphic sex chromosomes and are not amenable to controlled breeding: Nepenthes pitcher plants. We genotyped wild populations of flowering males and females of three Nepenthes taxa using ddRAD-seq, and sequenced a male inflorescence transcriptome. We developed a novel statistical tool (privacy rarefaction) to distinguish true sex-specificity from stochastic noise in high-throughput sequencing data. Our results support XY-systems in all three Nepenthes taxa and in Silene latifolia which was used as a positive control for its known XY-system. The male-specific region of the Y chromosome showed little conservation among the three Nepenthes taxa, except for the essential pollen development gene DYT1 which was also male-specific in additional taxa. Hence, this homomorphic XY sex-determination system likely has a unique origin older than the crown of the genus Nepenthes at c. 17.7 My. In addition to the characterisation of the previously unknown sex chromosomes of Nepenthes, our work contributes an innovative, highly sensitive statistical method to efficiently detect sex-specific genomic regions in wild populations in general.

Primary sex determination in the nematode C. elegans

Development ◽  
1987 ◽  
Vol 101 (Supplement) ◽  
pp. 5-16 ◽  
Author(s):  
Jonathan Hodgkin
Keyword(s):  
Sex Determination ◽  
X Chromosome ◽  
Germ Line ◽  
X Chromosomes ◽  
C Elegans ◽  
Female Sex ◽  
Determination System ◽  
One Step ◽  
Sex Determination System ◽  
Specific Control

Most nematodes have XO male/XX female sex determination. C. elegans is anomalous, having XX hermaphrodites rather than females. The hermaphrodite condition appears to result from the modification of a basic male/female sex-determination system, which permits both spermatogenesis and oogenesis to occur within a female soma. This modification is achieved by a germ-line-specific control acting at one step in a cascade of autosomal regulatory genes, which respond to X-chromosome dosage and direct male, female, or hermaphrodite development. Mutations of one of these genes can be used to construct artificial strains with ZZ male/WZ female sex determination. Primary sex determination normally depends on the ratio of X chromosomes to autosomes, as in Drosophila, and there appear to be multiple sites on the X chromosome that contribute to this ratio. Also, as in Drosophila, X-chromosome expression is compensated to equalize gene activity in XX and XO animals. Interactions between dosage compensation and sex determination are described and discussed.

scholarly journals A novel sex determination system in a close relative of the house mouse

2009 ◽  
Vol 277 (1684) ◽  
pp. 1049-1056 ◽  
Author(s):  
Frederic Veyrunes ◽  
Pascale Chevret ◽  
Josette Catalan ◽  
Riccardo Castiglia ◽  
Johan Watson ◽  
...  
Keyword(s):  
Sex Determination ◽  
House Mouse ◽  
Sex Chromosome ◽  
High Mobility ◽  
Close Relative ◽  
Mammal Species ◽  
Determination System ◽  
African Pygmy Mouse ◽  
Mus Minutoides ◽  
Sex Determination System

Therian mammals have an extremely conserved XX/XY sex determination system. A limited number of mammal species have, however, evolved to escape convention and present aberrant sex chromosome complements. In this study, we identified a new case of atypical sex determination in the African pygmy mouse Mus minutoides , a close evolutionary relative of the house mouse. The pygmy mouse is characterized by a very high proportion of XY females (74%, n = 27) from geographically widespread Southern and Eastern African populations. Sequencing of the high mobility group domain of the mammalian sex determining gene Sry , and karyological analyses using fluorescence in situ hybridization and G-banding data, suggest that the sex reversal is most probably not owing to a mutation of Sry , but rather to a chromosomal rearrangement on the X chromosome. In effect, two morphologically different X chromosomes were identified, one of which, designated X*, is invariably associated with sex-reversed females. The asterisk designates the still unknown mutation converting X*Y individuals into females. Although relatively still unexplored, such an atypical sex chromosome system offers a unique opportunity to unravel new genetic interactions involved in the initiation of sex determination in mammals.

scholarly journals The African Bullfrog (Pyxicephalus adspersus) genome unites the two ancestral ingredients for making vertebrate sex chromosomes

2018 ◽  
Author(s):  
Robert D. Denton ◽  
Randal S. Kudra ◽  
Jacob W. Malcom ◽  
Louis Du Preez ◽  
John H. Malone
Keyword(s):  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Genomic Sequence ◽  
Gene Dose ◽  
Ancestral Chromosome ◽  
Heteromorphic Sex Chromosomes ◽  
History Of ◽  
Determination System ◽  
Repeated Use ◽  
Sex Determination System

ABSTRACTHeteromorphic sex chromosomes have evolved repeatedly among vertebrate lineages despite largely deleterious reductions in gene dose. Understanding how this gene dose problem is overcome is hampered by the lack of genomic information at the base of tetrapods and comparisons across the evolutionary history of vertebrates. To address this problem, we produced a chromosome-level genome assembly for the African Bullfrog (Pyxicephalus adspersus)—an amphibian with heteromorphic ZW sex chromosomes—and discovered that the Bullfrog Z is surprisingly homologous to substantial portions of the human X. Using this new reference genome, we identified ancestral synteny among the sex chromosomes of major vertebrate lineages, showing that non-mammalian sex chromosomes are strongly associated with a single vertebrate ancestral chromosome, while mammals are associated with another that displays increased haploinsufficiency. The sex chromosomes of the African Bullfrog however, share genomic blocks with both humans and non-mammalian vertebrates, connecting the two ancestral chromosome sequences that repeatedly characterize vertebrate sex chromosomes. Our results highlight the consistency of sex-linked sequences despite sex determination system lability and reveal the repeated use of two major genomic sequence blocks during vertebrate sex chromosome evolution.

scholarly journals Inferring the genetic basis of sex determination from the genome of a dioecious nightshade

2020 ◽  
Author(s):  
Meng Wu ◽  
Gregory J. Anderson ◽  
Matthew W. Hahn ◽  
Leonie C. Moyle ◽  
Rafael F. Guerrero
Keyword(s):  
Sex Determination ◽  
Genetic Basis ◽  
De Novo ◽  
Expression Patterns ◽  
Gene Family Evolution ◽  
Genetic Mechanisms ◽  
Determination System ◽  
Heterogametic Sex ◽  
Sex Determination System ◽  
Evolution Of Dioecy

ABSTRACTDissecting the genetic mechanisms underlying dioecy (i.e. separate female and male individuals) is critical for understanding the evolution of this pervasive reproductive strategy. Nonetheless, the genetic basis of sex determination remains unclear in many cases, especially in systems where dioecy has arisen recently. Within the economically important plant genus Solanum (∼2000 species), dioecy is thought to have evolved independently at least 4 times across roughly 20 species. Here, we generate the first genome sequence of a dioecious Solanum and use it to ascertain the genetic basis of sex determination in this species. We de novo assembled and annotated the genome of S. appendiculatum (assembly size: ∼750 Mb; scaffold N50: 0.92 Mb; ∼35,000 genes), identified sex-specific sequences and their locations in the genome, and inferred that males in this species are the heterogametic sex. We also analyzed gene expression patterns in floral tissues of males and females, finding ∼100 genes that are differentially expressed between the sexes. These analyses, together with observed patterns of gene-family evolution specific to S. appendiculatum, consistently implicate a suite of genes from the regulatory network controlling pectin degradation and modification in the expression of sex. Furthermore, the genome of a species with a relatively young sex determination system provides the foundational resources for future studies on the independent evolution of dioecy in this speciose clade.

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