An undescribed karyotype for Thaptomys (2n = 50) and the mechanism of differentiation from Thaptomys nigrita (2n = 52) evidenced by FISH and Ag-NORs

Ventura, Karen; Silva, Maria José de Jesus; Fagundes, Valéria; Pardini, Renata; Yonenaga‐Yassuda, Yatiyo

doi:10.1080/00087114.2004.10589376

Cited by 17 publications

(19 citation statements)

References 10 publications

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“…(DSP7 and DSP19) and 1 acrocentric of D. kempi (DKE4). Tandem translocation poly- morphisms are considered to be strongly underdominant compared to other chromosomal rearrangements [see Navarro and Barton, 2003;Rieseberg and Livingstone, 2003], but are recurrent in closely related species of sigmodontine rodents belonging to the genera Akodon, Nectomys, Thaptomys, Sigmodon, Juliomys and Rhipidomys [Yonenaga-Yassuda et al, 1988;Silva and Yonenaga-Yassuda, 1998;Volobouev and Catzeflis, 2000;Ventura et al, 2004Ventura et al, , 2006Ventura et al, , 2009Paresque et al, 2009;Swier et al, 2009]. Both Deltamys forms lack the small metacentric pair, which constitutes a karyotypic characteristic that distinguishes Deltamys from its closely related genus Akodon [Fronza et al, 1981].…”

Section: Discussionmentioning

confidence: 99%

A New Allopatric Lineage of the Rodent Deltamys (Rodentia: Sigmodontinae) and the Chromosomal Evolution in Deltamys kempi and Deltamys sp.

Ventura

Fagundes

D’Elı́a

et al. 2011

Cytogenet Genome Res

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Deltamys Thomas 1917 is a poorly studied and rarely collected taxon of Akodontini (Sigmodontinae). The single described species, Deltamys kempi (DKE), has a basic karyotype with a diploid number of 2n = 37 in males and 2n = 38 in females, a fundamental number FN = 38 for both sexes, and an X₁X₁X₂X₂/X₁X₂Y sex determination system. Herein, a new allopatric form, Deltamys sp. (DSP), is reported, based on specimens from southern Brazil, with 2n = 40, FN = 40 and XX/XY sex chromosomes. We describe the karyotype and mechanism of chromosomal differentiation between both Deltamys complements. Phylogenetic analyses, based on the complete sequence (1,140 bp) of the mitochondrial cytochrome b gene, grouped Deltamys sp. as sister species to D. kempi, with up to 12% genetic divergence between them. The GTG-banding patterns show complete autosomal correspondence between D. kempi and Deltamys sp. and identify a tandem rearrangement involving DSP7, DSP19 and DKE4 that is responsible for the differences in 2n and FN. Chromosome painting with Akodon paranaensis chromosome 21 (a small metacentric akodont marker) paint revealed total homology with the smallest acrocentric Deltamys sp. chromosome, DSP19. This suggests the occurrence of a pericentric inversion or centromeric shift when compared to other akodontines, with a posterior tandem rearrangement giving rise to DKE4. In DKE, large blocks of pericentromeric constitutive heterochromatin are present on the autosomes and the X, and the Y/autosome has an entirely heterochromatic short arm. In DSP, small heterochromatic blocks are observed on autosomes and X, and the Y is a very small, mostly heterochromatic acrocentric. The cytogenetic analyses suggest that the Deltamys sp. karyotype is ancestral, with the derived condition resulting from a tandem fusion (DSP7 + DSP19) and the Y/autosome translocation giving rise to the multiple sex chromosome system. The autosomal rearrangements, the differences in CBG-banding patterns and Ag-NOR localization, as well as the presence of X₁X₁X₂X₂/X₁X₂Y and XX/XY sex determination mechanisms, possibly acting as a reproductive barrier, and the phylogenetic position within the Deltamys genus, with high genetic divergence, call for a taxonomic review of the genus.

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Section: Discussionmentioning

confidence: 99%

A New Allopatric Lineage of the Rodent Deltamys (Rodentia: Sigmodontinae) and the Chromosomal Evolution in Deltamys kempi and Deltamys sp.

Ventura

Fagundes

D’Elı́a

et al. 2011

Cytogenet Genome Res

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“…Some studies described interstitial telomeric sites as a result of remaining telomeres of chromosome rearrangements in karyotypes of cervids (Lee et al, 1993;Yang et al, 1997), giraffes (Petit et al, 1994;Vermeesh et al, 1996), rodents (Fagundes et al, 1997;Silva and Yonenaga-Yassuda 1998a;Ventura et al, 2004;Vieira et al, 2004) and lizards (Pellegrino et al, 1999). On the other hand, ITS associated with non-telomeric regions of the chromosomes are common in some groups and hybridization to pericentromeric regions are also frequently observed.…”

mentioning

confidence: 99%

“…Several reports have associated the presence of interstitial telomeric signals (ITS) with the occurrence of structural and/or numerical chromosome changes, such as Robertsonian rearrangements, pericentric inversion and tandem fusion/fission (Fagundes et al, 1997;Silva and Yonenaga-Yassuda, 1998a;Pellegrino et al, 1999;Ventura et al, 2004). Some studies described interstitial telomeric sites as a result of remaining telomeres of chromosome rearrangements in karyotypes of cervids (Lee et al, 1993;Yang et al, 1997), giraffes (Petit et al, 1994;Vermeesh et al, 1996), rodents (Fagundes et al, 1997;Silva and Yonenaga-Yassuda 1998a;Ventura et al, 2004;Vieira et al, 2004) and lizards (Pellegrino et al, 1999).…”

mentioning

confidence: 99%

Non-telomeric sites as evidence of chromosomal rearrangement and repetitive (TTAGGG)n arrays in heterochromatic and euchromatic regions in four species of Akodon (Rodentia, Muridae)

Ventura¹,

Silva²,

Fagundes³

et al. 2006

Cytogenet Genome Res

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Comparative studies among four species – Akodonazarae (2n = 38), A. lindberghi (2n = 42), A. paranaensis (2n = 44) and A. serrensis (2n = 46) – employing classic cytogenetics (C- and G-bands) and fluorescence in situ hybridization with telomeric (TTAGGG)_n sequencesare reported here. Non-telomeric signals in addition to the regular telomeric sites were detected in three species:A. azarae, A. lindberghi and A. serrensis. One interstitial telomeric site (ITS) was observed proximally at the long arm of chromosome 1 of A. azarae. The comparison of G-banding patterns among the species indicated that the ITS was due to a tandem fusion/fission rearrangement. Non-telomeric signals of A. lindberghi and A. serrensis were not related to chromosomal rearrangements; instead, the sequences co-localized with (i) heterochromatic regions of all chromosomes in A. serrensis; (ii) some heterochromatic regions in A. lindberghi, and (iii) both euchromatic and heterochromatic regions in the metacentric pair of A. lindberghi. These exceptional findings revealed that ITS in Akodon can be related to chromosomal rearrangements and repetitive sequences in the constitutive heterochromatin and that the richness of TTAGGG-like sequences in the euchromatin could be hypothesized to be a result of amplification of the referred sequence along the chromosome arms.

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“…O cromossomo X apresentou-se na forma acrocêntrica e grande, uma vez que ambos os indivíduos cariotipados eram fêmeas, não foi possível caracterizar a morfologia do cromossomo Y, mas segundo Paresque et al (2004) Papéis Avulsos de Zoologia, 56(7), 2016Olifiers et al, 2007;Tortato et al, 2014). Porém, Ventura et al (2004) descreveram um carió-tipo de 2n = 50 e NF A = 48 para indivíduos de Una, no estado da Bahia, que possuíam morfologia externa indistinguível de indivíduos 2n = 52. Os autores sugerem que essa variação pertença a uma nova espécie críptica de Thaptomys.…”

Section: Thaptomys Nigrita (Lichtenstein 1829)unclassified

Diversidade, biogeografia, caracterização cariotípica e tricológica dos pequenos mamíferos não voadores do Parque Estadual Rio da Onça, Litoral Sul do Paraná

et al. 2016

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An undescribed karyotype for Thaptomys (2n = 50) and the mechanism of differentiation from Thaptomys nigrita (2n = 52) evidenced by FISH and Ag-NORs

Abstract: (2004) An undescribed karyotype for Thaptomys (2n = 50) and the mechanism of differentiation from Thaptomysnigrita (2n = 52) evidenced by FISH and Ag-NORs,

Cited by 17 publications

References 10 publications

A New Allopatric Lineage of the Rodent <i>Deltamys</i> (Rodentia: Sigmodontinae) and the Chromosomal Evolution in <i>Deltamys kempi</i> and <i>Deltamys</i> sp.

A New Allopatric Lineage of the Rodent <i>Deltamys</i> (Rodentia: Sigmodontinae) and the Chromosomal Evolution in <i>Deltamys kempi</i> and <i>Deltamys</i> sp.

Non-telomeric sites as evidence of chromosomal rearrangement and repetitive (TTAGGG)<sub>n </sub>arrays in heterochromatic and euchromatic regions in four species of <i>Akodon</i> (Rodentia, Muridae)

Diversidade, biogeografia, caracterização cariotípica e tricológica dos pequenos mamíferos não voadores do Parque Estadual Rio da Onça, Litoral Sul do Paraná

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