scholarly journals Evolution of sex determination and heterogamety changes in section Otites of the genus Silene

2018 ◽  
Author(s):  
Veronika Balounova, ◽  
Roman Gogela ◽  
Radim Cegan ◽  
Patrik Cangren ◽  
Jitka Zluvova ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Sex Determination ◽  
Sex Chromosome ◽  
The Other ◽  
Close Relative ◽  
Sequence Analyses ◽  
Female Heterogamety ◽  
Genus Silene ◽  
Plant Sex ◽  
Male Heterogamety

AbstractSwitches in heterogamety occasionally occur both in animals and plants, although plant sex determination systems are mostly more recently evolved than those of animals, and have had less time for switches to occur. However, our previous research revealed a switch in heterogamety in section Otites of the plant genus Silene.Here we analyse in detail the evolution of genetic sex determination in section Otites, which is estimated to have evolved about 0.55 MYA. Our study confirms female heterogamety in S. otites and newly reveals female heterogamety in S. borysthenica. Sequence analyses and genetic mapping show that the sex-linked regions of these two species are the same, but the region in S. colpophylla, a close relative with male heterogamety, is different. The sex chromosome pairs of S. colpophylla and S. otites each correspond to an autosome of the other species, and both differ from the XY pair in S. latifolia, in a different section of the genus. Our phylogenetic analysis suggests a possible change from female to male heterogamety within Silene section Otites, making these species suitable for detailed studies of the events involved.

Weak male-determining genes and female heterogamety in Chironomus tentans

1984 ◽  
Vol 26 (6) ◽  
pp. 748-751
Author(s):  
Ray Feraday
Keyword(s):  
Sex Determination ◽  
Sex Chromosome ◽  
Chironomus Tentans ◽  
Female Development ◽  
Female Heterogamety ◽  
Dominant Female

Female heterogamety in the midge Chironomus tentans has been previously reported and attributed to a dominant female determiner. Published results are not consistent with the interpretation, and the female heterogamety, if any, can be better explained by a model involving a weakened male determiner. Suggestions are made for crosses between populations with different sex-determining mechanisms that would discriminate between models for the evolution of female heterogamety, and serve to determine whether indeed female development is the norm in the absence of any parental sex chromosomes.Key words: Chironomus, heterogamety, sex determination, sex chromosome.

scholarly journals Do male and female heterogamety really differ in expression regulation? Lack of global dosage balance in pygopodid geckos

2021 ◽  
Vol 376 (1833) ◽  
pp. 20200102 ◽  
Author(s):  
Michail Rovatsos ◽  
Tony Gamble ◽  
Stuart V. Nielsen ◽  
Arthur Georges ◽  
Tariq Ezaz ◽  
...  
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Gene Dosage ◽  
Regulatory Mechanisms ◽  
Gene Copy ◽  
Male And Female ◽  
Gene Dose ◽  
Female Heterogamety ◽  
Dosage Balance ◽  
Male Heterogamety

Differentiation of sex chromosomes is thought to have evolved with cessation of recombination and subsequent loss of genes from the degenerated partner (Y and W) of sex chromosomes, which in turn leads to imbalance of gene dosage between sexes. Based on work with traditional model species, theory suggests that unequal gene copy numbers lead to the evolution of mechanisms to counter this imbalance. Dosage compensation, or at least achieving dosage balance in expression of sex-linked genes between sexes, has largely been documented in lineages with male heterogamety (XX/XY sex determination), while ZZ/ZW systems are assumed to be usually associated with the lack of chromosome-wide gene dose regulatory mechanisms. Here, we document that although the pygopodid geckos evolved male heterogamety with a degenerated Y chromosome 32–72 Ma, one species in particular, Burton's legless lizard ( Lialis burtonis ), does not possess dosage balance in the expression of genes in its X-specific region. We summarize studies on gene dose regulatory mechanisms in animals and conclude that there is in them no significant dichotomy between male and female heterogamety. We speculate that gene dose regulatory mechanisms are likely to be related to the general mechanisms of sex determination instead of type of heterogamety. 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)’.

The Persevering Cytotaxonomy: Discovery of a Unique XX/XY Sex Chromosome System in Catfishes Suggests the Existence of a New, Endemic and Rare Species

2018 ◽  
Vol 156 (1) ◽  
pp. 45-55 ◽  
Author(s):  
Dinaíza A. Rocha-Reis ◽  
Karina de Oliveira Brandão ◽  
Lurdes F. de Almeida-Toledo ◽  
Rubens Pazza ◽  
Karine F. Kavalco
Keyword(s):  
Phylogenetic Analysis ◽  
Rare Species ◽  
Species Complex ◽  
Sex Chromosome ◽  
Supernumerary Chromosome ◽  
The Other ◽  
Allopatric Populations ◽  
Sex Chromosome System ◽  
Upper Paraná River ◽  
Upper Paraná River Basin

The genus Hypostomus has a broad geographic distribution in Brazilian rivers and comprises armored catfishes with a very complicated taxonomy due to the absence of morphological autapomorphies. The existence of nearly 10 allopatric populations with different karyotypes suggests that Hypostomusancistroides represents a species complex in the Upper Paraná River basin. In this paper, an unusual karyotype of an isolated H. aff. ancistroides population was investigated. All specimens of this sample have 2n = 66 chromosomes except for 1 male with 2n = 67, most likely due to a supernumerary chromosome. In this population, the sexes are dimorphic, the males are heterogametic, and an XX/XY sex chromosome system is present. Phylogenetic analysis using mitochondrial and nuclear DNAs indicated that this population forms a monophyletic group separate from the other populations of H.ancistroides and may represent an incipient species.

Are there female heterogametic strains of Chironomus tentans Fabricius?

1984 ◽  
Vol 26 (6) ◽  
pp. 743-747 ◽  
Author(s):  
Jon Martin ◽  
B. T. O. Lee
Keyword(s):  
Sex Determination ◽  
Published Data ◽  
Chironomus Tentans ◽  
Adequate Explanation ◽  
Male And Female ◽  
Female Heterogamety ◽  
Male Heterogamety

Although male heterogamety is the generally accepted method of sex determination in Chironomus, female heterogamety has been reported for some strains of Chironomus tentans. Some new data, combined with a reassessment of the published data, indicate that the proposal of female heterogamety rests on inconclusive data, while male heterogamety provides an adequate explanation of sex determination in C. tentans. A cross which would unambiguously discriminate between male and female heterogamety in these strains is proposed, although it is considered unlikely that female heterogamety exists in this species.Key words: sex determination, female heterogamety, Chironomus.

scholarly journals Memoirs: Chromosomes, Heredity and Sex: A Review of the Present State of the Evidence with regard to the Material Basis of Herditary Transmission and Sex-Determination

1914 ◽  
Vol s2-59 (236) ◽  
pp. 487-521
Author(s):  
L. DONCASTER
Keyword(s):  
Sex Determination ◽  
Present State ◽  
Direct Evidence ◽  
Sex Chromosome ◽  
The Other ◽  
The Third ◽  
Material Basis ◽  
Preliminary Account ◽  
Determining Factor

In the first section a summary is given of the main lines of argument leading to the conclusion that "Mendelian characters are determined by chromosomes." Some indication is given of the restrictions which must be placed on the meaning of this phrase in respect of the part played by the cytoplasm in heredity. It is concluded that the arguments in its favour, though very strong indirectly, are not supported by sufficient direct evidence to be regarded by themselves as indisputable. In the second section the chief classes of facts are reviewed which suggest a relation between chromosomes and sex-determination, and a preliminary account is given of a new case of an unpaired "sex-chromosome" in the female, in a strain of the moth Abraxas. It is concluded that the arguments for a relation between chromosomes and sex are much stronger than those counecting chromosomes with Mendelian factors. In the third section the facts of sex-limited inheritance are discussed; these are regarded as strongly reinforcing the arguments of the two preceding sections. Lastly, certain difficulties are considered, and it is concluded that sex cannot be determined directly by the presence or absence of a factor which merely determines whether an ovary or a testis shall develop, but that the determining factor causes a certain type of metabolism, which in turn leads to the production of one sex or the other. If such a metabolism is induced by other causes, an individual of one sex may probably arise from gametes which, in the absence of disturbing causes, would have given rise to the other sex.

Do male and female heterogamety really differ in expression regulation? Lack of global dosage balance in pygopodid geckos

2020 ◽  
Author(s):  
Michail Rovatsos ◽  
Tony Gamble ◽  
Stuart V. Nielsen ◽  
Arthur Georges ◽  
Tariq Ezaz ◽  
...  
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Gene Dosage ◽  
Regulatory Mechanisms ◽  
Gene Copy ◽  
Male And Female ◽  
Gene Dose ◽  
Female Heterogamety ◽  
Dosage Balance ◽  
Male Heterogamety

AbstractDifferentiation of sex chromosomes is thought to have evolved with cessation of recombination and subsequent loss of genes from the degenerated partner (Y and W) of sex chromosomes, which in turn leads to imbalance of gene dosage between sexes. Based on work with traditional model species, theory suggests that unequal gene copy numbers lead to the evolution of mechanisms to counter this imbalance. Dosage compensation, or at least achieving dosage balance in expression of sex-linked genes between sexes, has largely been documented in lineages with male heterogamety (XX/XY sex determination), while ZZ/ZW systems are assumed to be usually associated with the lack of chromosome-wide gene dose regulatory mechanisms. Here we document that although the pygopodid geckos evolved male heterogamety with a degenerated Y chromosome 32-72 million years ago, one species in particular, Burton’s legless lizard (Lialis burtonis), does not possess dosage balance in the expression of genes in its X-specific region. We summarize studies on gene dose regulatory mechanisms in animals and conclude that there is in them no significant dichotomy between male and female heterogamety. We speculate that gene dose regulatory mechanisms are likely to be related to the general mechanisms of sex determination instead of type of heterogamety.

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 Chromosome-scale assembly of the genome of Salix dunnii reveals a male-heterogametic sex determination system on chromosome 7

2020 ◽  
Author(s):  
Li He ◽  
Kai-Hua Jia ◽  
Ren-Gang Zhang ◽  
Yuan Wang ◽  
Tian-Le Shi ◽  
...  
Keyword(s):  
Sex Determination ◽  
Sex Chromosome ◽  
Purifying Selection ◽  
Pericentromeric Region ◽  
Chromosome 7 ◽  
Protein Coding ◽  
Long Reads ◽  
Heterogametic Sex ◽  
Sex Determination System ◽  
Male Heterogamety

AbstractSex determination systems in plants can involve either female or male heterogamety (ZW or XY, respectively). Here we used Illumina short reads, Oxford Nanopore Technologies (ONT) long reads, and Hi-C reads to assemble the first chromosome-scale genome of a female willow tree (Salix dunnii), and to predict genes using transcriptome sequences and available databases. The final genome sequence of 328 Mb in total was assembled in 29 contigs, and includes 31,501 genes. We inferred a male heterogametic sex determining factor on chromosome 7, suggesting that, unlike the female heterogamety of most species in the genus Salix, male heterogamety evolved in the subgenus Salix. The S. dunnii X-linked region occupies about 3.21 Mb of chromosome 7, and is probably in a pericentromeric region. Our data suggest that this region is enriched for transposable element insertions, and about one third of its 124 protein-coding genes were gained via duplications from other genome regions. We detect purifying selection on the genes that were ancestrally present in the region, though some have been lost. Transcriptome data from female and male individuals show more male- than female-biased genes in catkin and leaf tissues, and indicate enrichment for male-biased genes in the pseudo-autosomal regions. Our study provides valuable genomic resources for studying sex chromosome evolution in Salicaceae family.

scholarly journals On the origin of sex chromosomes from meiotic drive

2015 ◽  
Vol 282 (1798) ◽  
pp. 20141932 ◽  
Author(s):  
Francisco Úbeda ◽  
Manus M. Patten ◽  
Geoff Wild
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Meiotic Drive ◽  
The Other ◽  
Evolution Of Sex ◽  
Dioecious Species

Most animals and many plants make use of specialized chromosomes (sex chromosomes) to determine an individual's sex. Best known are the XY and ZW sex-determination systems. Despite having evolved numerous times, sex chromosomes present something of an evolutionary puzzle. At their origin, alleles that dictate development as one sex or the other (primitive sex chromosomes) face a selective penalty, as they will be found more often in the more abundant sex. How is it possible that primitive sex chromosomes overcome this disadvantage? Any theory for the origin of sex chromosomes must identify the benefit that outweighs this cost and enables a sex-determining mutation to establish in the population. Here we show that a new sex-determining allele succeeds when linked to a sex-specific meiotic driver. The new sex-determining allele benefits from confining the driving allele to the sex in which it gains the benefit of drive. Our model requires few special assumptions and is sufficiently general to apply to the evolution of sex chromosomes in outbreeding cosexual or dioecious species. We highlight predictions of the model that can discriminate between this and previous theories of sex-chromosome origins.

scholarly journals Preface

2021 ◽  
Vol 376 (1832) ◽  
pp. 20200088
Author(s):  
Lukáš Kratochvíl ◽  
Matthias Stöck
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Chromosome Evolution ◽  
Sex Chromosome ◽  
Sex Chromosome Evolution ◽  
Evolution Of Sex ◽  
Linkage Groups ◽  
Theme Issue ◽  
Female Heterogamety

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)’.

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