Cryptic Species in Proechimys goeldii (Rodentia, Echimyidae)? A Case of Molecular and Chromosomal Differentiation in Allopatric Populations

2016 ◽  
Vol 148 (2-3) ◽  
pp. 199-210 ◽  
Author(s):  
Marlyson J. Rodrigues da Costa ◽  
Paulo J. Siqueira do Amaral ◽  
Julio C. Pieczarka ◽  
Maria I. Sampaio ◽  
Rogério V. Rossi ◽  
...  
Keyword(s):  
Cryptic Species ◽  
Sex Chromosome ◽  
Centric Fusion ◽  
Wide Distribution ◽  
Cyt B ◽  
Meiotic Analysis ◽  
Xingu River ◽  
Areas Of Endemism ◽  
Determination System ◽  
Tocantins River

The spiny rats of the genus Proechimys have a wide distribution in the Amazon, covering all areas of endemism of this region. We analyzed the karyotype and cytochrome b (Cyt b) sequences in Proechimys goeldii from 6 localities representing 3 interfluves of the eastern Amazon. A clear separation of P. goeldii into 2 monophyletic clades was observed, both chromosomally and based on Cyt b sequences: cytotype A (2n = 26♀/27♂, NF = 42) for samples from the Tapajos-Xingu interfluve and cytotype B (2n = 24♀/25♂, NF = 42) for samples from the Xingu-Tocantins interfluve and east of the Tocantins River. The karyotypes differ in a pericentric inversion and a centric fusion/fission and an average nucleotide divergence of 6.1%, suggesting cryptic species. Meiotic analysis confirmed the presence of a XX/XY1Y2 multiple sex chromosome determination system for both karyotypes. The karyotypes also vary from the literature (2n = 24, NF = 42, XX/XY). The autosome translocated to the X chromosome is different both in size and morphology to P. cf. longicaudatus, which also has a multiple sex chromosome determination system (2n = 14♀/15♀♂/16♀/17♂, NF = 14). The Xingu River is a barrier that separates populations of P. goeldii, thus maintaining their allopatric nature and providing an explanation for the molecular and cytogenetic patterns observed for the Xingu River but not the Tocantins River.

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)’.

The meiotic behaviour of natural F1 hybrids between Trimerotropis suffusa Scudder and T. cyaneipennis Bruner (Orthoptera: Oedipodinae)

1983 ◽  
Vol 25 (5) ◽  
pp. 467-477 ◽  
Author(s):  
Bernard John ◽  
David C. Lightfoot ◽  
David B. Weissman
Keyword(s):  
Centric Fusion ◽  
Variable Number ◽  
Meiotic Behaviour ◽  
F1 Hybrids ◽  
Genotypic Differences ◽  
Meiotic Analysis ◽  
Sparse Vegetation ◽  
West Texas ◽  
Mendocino County ◽  
Division Spindle

Trimerotropis suffusa Scudder is a species which ranges from the Rocky Mountains to the Californian Sierras and the Cascade Mountains of Oregon. Additionally, to the south, it is found along the coast of California to Mendocino County. Trimerotropis cyaneipennis Bruner has a distribution from West Texas through New Mexico, Arizona, Colorado, Utah, and Nevada to southern Oregon and southern California. These two species are most commonly ecologically isolated from each other, the latter generally occurring in desert regions or those with sparse vegetation whereas T. suffusa is found in woodland situations (Strohecker et al. 1968). Even where they approximate in their distributions, the ecotones which separate them are normally broad enough to preclude contact between them. These species have, however, been found in microsympatry in a narrow ecotone in the Pueblo Mountains of Southeast Oregon. Hybrid individuals intermediate in morphology, crepitation, and diploid chromosome number occur within this ecotone. A meiotic analysis of three such hybrid males indicates that the parental species are distinguished by a fixed centric fusion. This difference tends to be obscured in the parental karyotypes which both contain a variable number of metacentric chromosomes, some fixed and some polymorphic, of inversion origin. Meiotic behaviour also identifies two potential sources of infertility in these hybrids. First, irregular segregation of the fusion chromosomes, following either linear orientation of the three-multiple chain or else from failure of the chain to form. Second, pairing failure, usually in one less commonly in two, of the autosomal pairs not involved in the fusion system. The extent of these anomalies varied between the three hybrid individuals indicating that genotypic differences between the parents also play a role in determining multiple orientation and the levels of pairing failure in both the multiple and in the other autosomes which form univalents. The univalents that do form may either segregate at random or may lag on the first division spindle. In the latter event they inhibit cytokinesis at first division, and sometimes also at second division, giving rise to macrospermatids which are, respectively, diploid (2x) or tetraploid (4x). The net result of such an anomalous meiosis is that most of the sperm produced by all three hybrids is either polyploid or aneuploid.

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.

Genomic, chromosomal, and ecological differentiation between the cryptic Eurasian malaria vector-species Anopheles messeae and Anopheles daciae

2019 ◽  
Author(s):  
Anastasia N. Naumenko ◽  
Dmitriy A. Karagodin ◽  
Andrey A. Yurchenko ◽  
Anton V. Moskaev ◽  
Olga I. Martin ◽  
...  
Keyword(s):  
Reproductive Isolation ◽  
Cryptic Species ◽  
X Chromosome ◽  
Malaria Vector ◽  
Genomic Sequence ◽  
Wide Distribution ◽  
Its2 Sequence ◽  
Genetic Introgression ◽  
Nucleotide Substitutions ◽  
Ecological Differentiation

Abstract Background A dominant malaria vector, Anopheles messeae, is a highly polymorphic species with wide distribution throughout Eurasia. Five highly polymorphic inversions associated with the geographical distribution of the species have been reported. A sister species, An. daciae, was described and discriminated from An. messeae based on five fixed nucleotide substitutions in the internal transcribed spacer 2 (ITS2) of ribosomal DNA. However, the levels of genomic divergence, chromosomal variation, and ecological differentiation between these two cryptic species remain unexplored. Results In this study, we sequenced ITS2 and analyzed the inversion frequencies of 289 Anopheles larvae specimens collected from three locations in the Moscow region. We identified a high abundance of both An. messeae and An. daciae in all three locations. Five individual genomes for each species of An. messeae and An. daciae from one location were sequenced. Our study confirmed five previously described nucleotide substitutions in the ITS2 of An. messeae. However, we found that the ITS2 sequence in An. daciae was heterogenic in three of the five positions. Fixed nucleotide differences between An. messeae and An. daciae were found only in the last two positions. One mosquito was identified as a hybrid between An. messeae and An. daciae based on heterogeneous substitutions in all five positions. Although, the genomic sequence comparison demonstrated genome-wide divergence between the two species, which is especially pronounced on the X chromosome, an ADMIXTURE cluster analysis demonstrated the presence of two admixed individuals suggesting ongoing hybridization. Cytogenetic analysis demonstrated that An. messeae and An. daciae significantly differ from each other by their frequency of polymorphic inversions. Inversion X1 was fixed in An. messeae but was polymorphic in all An. daciae populations. The frequency of polymorphic autosomal inversions was higher in An. messeae than in An. daciae. The species composition was different among the studied locations suggesting species-specific ecological preferences. Conclusions Our study demonstrated that An. messeae and An. daciae represent closely related cryptic species with incomplete reproductive isolation that are able to maintain genomic differentiation in sympatry despite ongoing genetic introgression. The X chromosome plays an important role in the reproductive isolation between the species.

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 Do Cryptic Species Exist in Hoplobatrachus rugulosus? An Examination Using Four Nuclear Genes, the Cyt b Gene and the Complete MT Genome

PLoS ONE ◽  
2015 ◽  
Vol 10 (4) ◽  
pp. e0124825 ◽  
Author(s):  
Danna Yu ◽  
Jiayong Zhang ◽  
Peng Li ◽  
Rongquan Zheng ◽  
Chen Shao
Keyword(s):  
Cryptic Species ◽  
Nuclear Genes ◽  
Cyt B ◽  
Cyt B Gene ◽  
Mt Genome

scholarly journals Paracoccidioidomycosis: Current Perspectives from Brazil

2017 ◽  
Vol 11 (1) ◽  
pp. 224-282 ◽  
Author(s):  
Rinaldo Poncio Mendes ◽  
Ricardo de Souza Cavalcante ◽  
Sílvio Alencar Marques ◽  
Mariângela Esther Alencar Marques ◽  
James Venturini ◽  
...  
Keyword(s):  
Latin America ◽  
Cryptic Species ◽  
Geographical Distribution ◽  
Genetic Factors ◽  
Wide Distribution ◽  
Review Article ◽  
Serological Diagnosis ◽  
Cell Mediated Immunity ◽  
First Choice ◽  
Parameters Of Accuracy

Background:This review article summarizes and updates the knowledge on paracoccidioidomycosis.P lutziiand the cryptic species ofP. brasiliensisand their geographical distribution in Latin America, explaining the difficulties observed in the serological diagnosis.Objectives:Emphasis has been placed on some genetic factors as predisposing condition for paracoccidioidomycosis. Veterinary aspects were focused, showing the wide distribution of infection among animals. The cell-mediated immunity was better characterized, incorporating the recent findings.Methods:Serological methods for diagnosis were also compared for their parameters of accuracy, including the analysis of relapse.Results:Clinical forms have been better classified in order to include the pictures less frequently observesiod.Conclusion:Itraconazole and the trimethoprim-sulfamethoxazole combination was compared regarding efficacy, effectiveness and safety, demonstrating that azole should be the first choice in the treatment of paracoccidioidomycosis.

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.

Karyological analysis of an interspecific hybrid between the dioecious Silene latifolia and the hermaphroditic Silene viscosa

Genome ◽  
2006 ◽  
Vol 49 (4) ◽  
pp. 373-379 ◽  
Author(s):  
Michaela Markova ◽  
Martina Lengerova ◽  
Jitka Zluvova ◽  
Bohuslav Janousek ◽  
Boris Vyskot
Keyword(s):  
In Situ Hybridization ◽  
X Chromosome ◽  
Interspecific Hybrid ◽  
Sex Chromosome ◽  
Silene Latifolia ◽  
Meiotic Pairing ◽  
Meiotic Analysis ◽  
Karyological Analysis ◽  
Hybrid Genome

The genus Silene is a good model for studying evolution of the sex chromosomes, since it includes species that are hermaphroditic and dioecious, while maintain a basic chromosome number of 2n = 24. For some combinations of Silene species it is possible to construct interspecific hybrids. Here, we present a detailed karyological analysis of a hybrid between the dioecious Silene latifolia as the maternal plant and a related species, hermaphroditic Silene viscosa, used as a pollen partner. Using genomic probes (the genomic in situ hybridization (GISH) technique), we were able to clearly discriminate parental genomes and to show that they are largely separated in distinct nuclear domains. Molecular GISH and fluorescence in situ hybridization (FISH) markers document that the hybrid genome of somatic cells was strictly additive and stable, and that it had 12 chromosomes originating from each parent, including the only X chromosome of S. latifolia. Meiotic analysis revealed that, although related, respective parental chromosomes did not pair or paired only partially, which resulted in frequent chromosome abnormalities such as bridges and irregular non-disjunctions. GISH and FISH markers clearly document that the larger genome of S. latifolia and its largest chromosome component, the X chromosome, were mostly employed in chromosome lagging and misdivision.Key words: sex chromosome, Silene, interspecific hybrid, meiotic pairing, misdivision.

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