scholarly journals The Amazonian Red Side-Necked Turtle Rhinemys rufipes (Spix, 1824) (Testudines, Chelidae) Has a GSD Sex-Determining Mechanism with an Ancient XY Sex Microchromosome System

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 2088 ◽  
Author(s):  
Patrik F. Viana ◽  
Eliana Feldberg ◽  
Marcelo B. Cioffi ◽  
Vinicius Tadeu de Carvalho ◽  
Sabrina Menezes ◽  
...  
Keyword(s):  
South America ◽  
Sex Determination ◽  
Sex Chromosome ◽  
River Basins ◽  
Molecular Cytogenetic ◽  
Neotropical Species ◽  
Small Streams ◽  
Sex Chromosome System ◽  
Biological Aspects

The Amazonian red side-necked turtle Rhynemis rufipes is an endemic Amazonian Chelidae species that occurs in small streams throughout Colombia and Brazil river basins. Little is known about various biological aspects of this species, including its sex determination strategies. Among chelids, the greatest karyotype diversity is found in the Neotropical species, with several 2n configurations, including cases of triploidy. Here, we investigate the karyotype of Rhinemys rufipes by applying combined conventional and molecular cytogenetic procedures. This allowed us to discover a genetic sex-determining mechanism that shares an ancestral micro XY sex chromosome system. This ancient micro XY system recruited distinct repeat motifs before it diverged from several South America and Australasian species. We propose that such a system dates back to the earliest lineages of the chelid species before the split of South America and Australasian lineages.

scholarly journals Leuciscus (Pisces, Cyprinidae) karyotypes: Transect of Portuguese populations

1998 ◽  
Vol 21 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Maria João Collares-Pereira ◽  
M.I. Próspero ◽  
R.I. Biléu ◽  
E.M. Rodrigues
Keyword(s):  
Chromosome Numbers ◽  
Sex Chromosome ◽  
River Basins ◽  
Supernumerary Chromosome ◽  
Distribution Ranges ◽  
Structural Chromosome ◽  
Karyotype Structure ◽  
Sex Chromosome System ◽  
Submetacentric Pair ◽  
Hydrological Regimes

The presently described Iberian chubs - Leuciscus carolitertii and L. pyrenaicus - sampled throughout their distribution ranges in Portugal were cytogenetically analyzed. Their chromosome numbers were consistently 2n = 50, except for two specimens of L. carolitertii, which exhibited a supernumerary chromosome in some of the metaphases. The karyotypes were found to be highly typical for other Leuciscus taxa, as well as for European leuciscine cyprinids: the chromosome sets are dominated by metacentric and submetacentric elements with a reduced number of acrocentric pairs (three to four); the largest pair of the complements belongs typically to this latter category. The chubs from northern drainages, assignable to L. carolitertii, have apparently a more stable karyotype structure (12M:30S:8A) than the chubs from L. pyrenaicus, which have 12M:32S:6A, but may exhibit in the most southern river basins (Guadiana, Mira, Aljezur, Bordeira and Arade) more variable karyotypes. Besides, these data support the very recent discovery of two genetically distinct Leuciscus taxa in this region of the Iberian Peninsula, suggesting the stochastic fixation of structural chromosome rearrangements in these small and isolated drainages, which may be affected by bottlenecks due to significant variations in hydrological regimes. The NORs were apparently located in one small submetacentric pair of chromosomes and the presence of a heteromorphic sex chromosome system of the ZW/ZZ type was also evidenced for the Iberian endemic chubs.

Characterisation of ATRX, DMRT1, DMRT7 and WT1 in the platypus (Ornithorhynchus anatinus)

2009 ◽  
Vol 21 (8) ◽  
pp. 985 ◽  
Author(s):  
Enkhjargal Tsend-Ayush ◽  
Shu Ly Lim ◽  
Andrew J. Pask ◽  
Diana Demiyah Mohd Hamdan ◽  
Marilyn B. Renfree ◽  
...  
Keyword(s):  
Sex Determination ◽  
Expression Pattern ◽  
Sexual Development ◽  
Sex Chromosome ◽  
Z Chromosome ◽  
Testis Development ◽  
Y Chromosomes ◽  
Evolutionarily Conserved ◽  
Sex Chromosome System ◽  
Conserved Gene

One of the most puzzling aspects of monotreme reproductive biology is how they determine sex in the absence of the SRY gene that triggers testis development in most other mammals. Although monotremes share a XX female/XY male sex chromosome system with other mammals, their sex chromosomes show homology to the chicken Z chromosome, including the DMRT1 gene, which is a dosage-dependent sex determination gene in birds. In addition, monotremes feature an extraordinary multiple sex chromosome system. However, no sex determination gene has been identified as yet on any of the five X or five Y chromosomes and there is very little knowledge about the conservation and function of other known genes in the monotreme sex determination and differentiation pathway. We have analysed the expression pattern of four evolutionarily conserved genes that are important at different stages of sexual development in therian mammals. DMRT1 is a conserved sex-determination gene that is upregulated in the male developing gonad in vertebrates, while DMRT7 is a mammal-specific spermatogenesis gene. ATRX, a chromatin remodelling protein, lies on the therian X but there is a testis-expressed Y-copy in marsupials. However, in monotremes, the ATRX orthologue is autosomal. WT1 is an evolutionarily conserved gene essential for early gonadal formation in both sexes and later in testis development. We show that these four genes in the adult platypus have the same expression pattern as in other mammals, suggesting that they have a conserved role in sexual development independent of genomic location.

Molecular cytogenetic characterization of Rumex papillaris, a dioecious plant with an XX/XY1Y2 sex chromosome system

Genetica ◽  
2008 ◽  
Vol 135 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Rafael Navajas-Pérez ◽  
Trude Schwarzacher ◽  
Manuel Ruiz Rejón ◽  
Manuel A. Garrido-Ramos
Keyword(s):  
Sex Chromosome ◽  
Dioecious Plant ◽  
Molecular Cytogenetic ◽  
Cytogenetic Characterization ◽  
Sex Chromosome System

scholarly journals A derived ZW chromosome system in Amborella trichopoda, the sister species to all other extant flowering plants

2020 ◽  
Author(s):  
Jos Kafer ◽  
Adam Bewick ◽  
Amelie Andres-Robin ◽  
Garance Lapetoule ◽  
Alex Harkess ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Sex Determination ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Chromosome 9 ◽  
Male And Female ◽  
Recent Origin ◽  
Sex Chromosome System ◽  
Genetic And Environmental Factors ◽  
Evo Devo

Sex determination is poorly understood in plants. Amborella trichopoda is a well-known plant model for evo-devo studies, which is also dioecious (has male and female individuals), with an unknown sex determination mechanism. A. trichopoda is a sex switcher, which points to possible environmental factors that act on sex, but populations grown from seed under greenhouse conditions exhibit a 50:50 sex ratio, which indicates the operation of genetic factors. Here, we use a new method (SDpop) to identify sex-linked genes from genotyping data of male and female individuals sampled in the field, and find that A. trichopoda has a ZW sex-chromosome system. The sex-linked genes map to a 4 Mb sex-determining region on chromosome 9. The low extent of ZW divergence suggests these sex chromosomes are of recent origin, which is consistent with dioecy being derived character in the A. trichopoda lineage. Our work has uncovered clearly formed sex chromosomes in a species in which both genetic and environmental factors can influence sex.

scholarly journals Turtle Insights into the Evolution of the Reptilian Karyotype and the Genomic Architecture of Sex Determination

Genes ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 416 ◽  
Author(s):  
Basanta Bista ◽  
Nicole Valenzuela
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Chromosome Evolution ◽  
Sex Chromosome ◽  
Theoretical Models ◽  
Sex Chromosome Evolution ◽  
Ongoing Research ◽  
Genomic Resources ◽  
Genotypic Sex Determination ◽  
Sex Chromosome System

Sex chromosome evolution remains an evolutionary puzzle despite its importance in understanding sexual development and genome evolution. The seemingly random distribution of sex-determining systems in reptiles offers a unique opportunity to study sex chromosome evolution not afforded by mammals or birds. These reptilian systems derive from multiple transitions in sex determination, some independent, some convergent, that lead to the birth and death of sex chromosomes in various lineages. Here we focus on turtles, an emerging model group with growing genomic resources. We review karyotypic changes that accompanied the evolution of chromosomal systems of genotypic sex determination (GSD) in chelonians from systems under the control of environmental temperature (TSD). These transitions gave rise to 31 GSD species identified thus far (out of 101 turtles with known sex determination), 27 with a characterized sex chromosome system (13 of those karyotypically). These sex chromosomes are varied in terms of the ancestral autosome they co-opted and thus in their homology, as well as in their size (some are macro-, some are micro-chromosomes), heterogamety (some are XX/XY, some ZZ/ZW), dimorphism (some are virtually homomorphic, some heteromorphic with larger-X, larger W, or smaller-Y), age (the oldest system could be ~195 My old and the youngest < 25 My old). Combined, all data indicate that turtles follow some tenets of classic theoretical models of sex chromosome evolution while countering others. Finally, although the study of dosage compensation and molecular divergence of turtle sex chromosomes has lagged behind research on other aspects of their evolution, this gap is rapidly decreasing with the acceleration of ongoing research and growing genomic resources in this group.

Chromosomal Evolution in Aspredinidae (Teleostei, Siluriformes): Insights on Intra- and Interspecific Relationships with Related Groups

2020 ◽  
Vol 160 (9) ◽  
pp. 539-553
Author(s):  
Milena Ferreira ◽  
Isac S. de Jesus ◽  
Patrik F. Viana ◽  
Caroline Garcia ◽  
Daniele A. Matoso ◽  
...  
Keyword(s):  
Evolutionary Dynamics ◽  
Sex Chromosome ◽  
Chromosomal Evolution ◽  
Nucleotide Sequencing ◽  
Molecular Cytogenetic ◽  
System A ◽  
The Family ◽  
Sex Chromosome System ◽  
Acrocentric Chromosomes ◽  
Systematic Relationships

The family Aspredinidae comprises a clade of complex systematic relationships, both from molecular and morphological approaches. In this study, conventional and molecular cytogenetic studies coupled with nucleotide sequencing were performed in 6 Aspredininae species (<i>Amaralia hypsiura</i>, <i>Bunocephalus</i> cf. <i>aloikae</i>, <i>Bunocephalus amaurus</i>, <i>Bunocephalus</i> aff. <i>coracoideus</i>, <i>Bunocephalus verrucosus</i>, and <i>Platystacus cotylephorus</i>) from different locations of the Amazon hydrographic basin. Our results showed highly divergent diploid numbers (2n) among the species, ranging from 49 to 74, including the occurrence of an XX/X0 sex chromosome system. A neighbor-joining phylogram based on the cytochrome <i>c</i> oxidase I (<i>COI</i>) showed that <i>Bunocephalus coracoideus</i> is not a monophyletic clade, but closely related to <i>B. verrucosus.</i> The karyotypic data associated with <i>COI</i> suggest an ancestral karyotype for Aspredinidae with a reduced 2n, composed of bi-armed chromosomes and a trend toward chromosomal fissions resulting in higher diploid number karyotypes, mainly composed of acrocentric chromosomes. Evolutionary relationships were discussed under a phylogenetic context with related species from different Siluriformes families. The karyotype features and chromosomal diversity of Aspredinidae show an amazing differentiation, making this family a remarkable model for investigating the evolutionary dynamics in siluriforms as well as in fish as a whole.

scholarly journals A ZZ/ZW Sex Chromosome System in Cephalochordate Amphioxus

Genetics ◽  
2020 ◽  
Vol 214 (3) ◽  
pp. 617-622
Author(s):  
Chenggang Shi ◽  
Xiaotong Wu ◽  
Liuru Su ◽  
Chaoqi Shang ◽  
Xuewen Li ◽  
...  
Keyword(s):  
Sex Determination ◽  
Mutant Strain ◽  
Sex Chromosome ◽  
Female Offspring ◽  
Phylogenetic Position ◽  
Z Chromosome ◽  
Transcription Activator ◽  
Sex Chromosome System ◽  
Female Specific ◽  
Determination Mechanism

Sex determination is remarkably variable among animals with examples of environmental sex determination, male heterogametic (XX/XY) and female heterogametic (ZZ/ZW) chromosomal sex determination, and other genetic mechanisms. The cephalochordate amphioxus occupies a key phylogenetic position as a basal chordate and outgroup to vertebrates, but its sex determination mechanism is unknown. During the course of generating Nodal mutants with transcription activator-like effector nucleases (TALENs) in amphioxus Branchiostoma floridae, serendipitously, we generated three mutant strains that reveal the sex determination mechanism of this animal. In one mutant strain, all heterozygous mutant offspring over three generations were female and all wild-type descendants were male. This pattern suggests the Nodal allele targeted is on a female-specific W chromosome. A second mutant showed the same W-linked inheritance pattern, with a female heterozygote passing the mutation only to daughters. In a third mutant strain, both male and female offspring could be heterozygous, but a female heterozygote passed the mutation only to sons. This pattern is consistent with the targeted allele being on a Z chromosome. We found an indel polymorphism linked to a Nodal allele present in most females, but no males in our cultured population. Together, these results indicate that Nodal is sex chromosome-linked in B. floridae, and that B. floridae has a ZZ/ZW sex chromosome system.

scholarly journals The Diversity and Evolution of Sex Chromosomes in Frogs

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 483
Author(s):  
Wen-Juan Ma ◽  
Paris Veltsos
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Chromosome Evolution ◽  
Sex Chromosome ◽  
Comparative Genomic ◽  
Ancestral State ◽  
Heteromorphic Sex Chromosomes ◽  
Genomic Studies ◽  
Evolutionary Trajectories ◽  
Heterogametic Sex

Frogs are ideal organisms for studying sex chromosome evolution because of their diversity in sex chromosome differentiation and sex-determination systems. We review 222 anuran frogs, spanning ~220 Myr of divergence, with characterized sex chromosomes, and discuss their evolution, phylogenetic distribution and transitions between homomorphic and heteromorphic states, as well as between sex-determination systems. Most (~75%) anurans have homomorphic sex chromosomes, with XY systems being three times more common than ZW systems. Most remaining anurans (~25%) have heteromorphic sex chromosomes, with XY and ZW systems almost equally represented. There are Y-autosome fusions in 11 species, and no W-/Z-/X-autosome fusions are known. The phylogeny represents at least 19 transitions between sex-determination systems and at least 16 cases of independent evolution of heteromorphic sex chromosomes from homomorphy, the likely ancestral state. Five lineages mostly have heteromorphic sex chromosomes, which might have evolved due to demographic and sexual selection attributes of those lineages. Males do not recombine over most of their genome, regardless of which is the heterogametic sex. Nevertheless, telomere-restricted recombination between ZW chromosomes has evolved at least once. More comparative genomic studies are needed to understand the evolutionary trajectories of sex chromosomes among frog lineages, especially in the ZW systems.

scholarly journals Evolution of a Multiple Sex-Chromosome System by Three-Sequential Translocations among Potential Sex-Chromosomes in the Taiwanese Frog Odorrana swinhoana

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 661
Author(s):  
Ikuo Miura ◽  
Foyez Shams ◽  
Si-Min Lin ◽  
Marcelo de Bello Cioffi ◽  
Thomas Liehr ◽  
...  
Keyword(s):  
Sex Chromosomes ◽  
Rare Case ◽  
Sex Chromosome ◽  
Sex Chromosome System ◽  
Brown Frog ◽  
Male Specific

Translocation between sex-chromosomes and autosomes generates multiple sex-chromosome systems. It happens unexpectedly, and therefore, the evolutionary meaning is not clear. The current study shows a multiple sex chromosome system comprising three different chromosome pairs in a Taiwanese brown frog (Odorrana swinhoana). The male-specific three translocations created a system of six sex-chromosomes, ♂X1Y1X2Y2X3Y3 -♀X1X1X2X2X3X3. It is unique in that the translocations occurred among three out of the six members of potential sex-determining chromosomes, which are known to be involved in sex-chromosome turnover in frogs, and the two out of three include orthologs of the sex-determining genes in mammals, birds and fishes. This rare case suggests sex-specific, nonrandom translocations and thus provides a new viewpoint for the evolutionary meaning of the multiple sex chromosome system.

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