Phylogenetic analysis of G-banded karyotypes among the South American subterranean rodents of the genus Ctenomys (Caviomorpha: Octodontidae), with special reference to chromosomal evolution and speciation

The chromosomes of subterranean rodents of the South American genus Clenomys are highly variable with diploid numbers ranging from 10 to 70. The Phylogenetic relationships of this group have been analysed cladistically using G-banded karyorypes as have the chromosomal rearrangements involved in its...

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Guardado en:
Detalles Bibliográficos
Publicado: 1995
Materias:
Fossorial rodents - chromosomes - species - cladistic analysis
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00244066_v54_n1_p43_Ortells
http://hdl.handle.net/20.500.12110/paper_00244066_v54_n1_p43_Ortells
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00244066_v54_n1_p43_Ortells
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spelling paper:paper_00244066_v54_n1_p43_Ortells2023-06-08T14:52:16Z Phylogenetic analysis of G-banded karyotypes among the South American subterranean rodents of the genus Ctenomys (Caviomorpha: Octodontidae), with special reference to chromosomal evolution and speciation Fossorial rodents - chromosomes - species - cladistic analysis The chromosomes of subterranean rodents of the South American genus Clenomys are highly variable with diploid numbers ranging from 10 to 70. The Phylogenetic relationships of this group have been analysed cladistically using G-banded karyorypes as have the chromosomal rearrangements involved in its karyotypic differentiation. One group, called the 'Corrientes group', has very variable chromosomes but low allozymic and morphological differentiation among its members. This group has been analysed with respect to chromosomal speciation. Using a member of another subfamily (Octodonlomys gliroides) as an outgroup, the results indicate that karyotypes with low diploid and fundamental numbers are plesiomorphic. The range of diploid numbers studied here is between 22 and 70, while the fundamental numbers are between 40 and 86. It was found that the main chromosomal rearrangement that transforms karyotypes towards higher diploid and fundamental numbers is the acquisition of new chromosomal material via unknown mechanisms, followed by pericentric inversions that generate new chromosomal arms, centric fusions and centric fissions. In spite of their low differentiation regarding allozymic and morphological features, it was found that the karyomorphs of the Corrientes group have enough chromosomal differentiation to consider them as distinct species. Beside the range of diploid and fundamental numbers of this group (42-70 and 80-84 respectively), their pairwise chromosomal differences are high. The most closely related of them differ in one nonhomologous arm, one Robertsonian change and a whole chromosome duplication. The most differentiated taxa differ in 20 arms with lack of homology, 12 Robertsonian changes (one with monobrachial homology), six pericentric inversions and the above mentioned probable arm duplication. For these reasons, it is probable that some kind of chromosomal speciation has occurred in the Corrientes group. © 1995. 1995 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00244066_v54_n1_p43_Ortells http://hdl.handle.net/20.500.12110/paper_00244066_v54_n1_p43_Ortells
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Fossorial rodents - chromosomes - species - cladistic analysis
spellingShingle Fossorial rodents - chromosomes - species - cladistic analysis
Phylogenetic analysis of G-banded karyotypes among the South American subterranean rodents of the genus Ctenomys (Caviomorpha: Octodontidae), with special reference to chromosomal evolution and speciation
topic_facet Fossorial rodents - chromosomes - species - cladistic analysis
description The chromosomes of subterranean rodents of the South American genus Clenomys are highly variable with diploid numbers ranging from 10 to 70. The Phylogenetic relationships of this group have been analysed cladistically using G-banded karyorypes as have the chromosomal rearrangements involved in its karyotypic differentiation. One group, called the 'Corrientes group', has very variable chromosomes but low allozymic and morphological differentiation among its members. This group has been analysed with respect to chromosomal speciation. Using a member of another subfamily (Octodonlomys gliroides) as an outgroup, the results indicate that karyotypes with low diploid and fundamental numbers are plesiomorphic. The range of diploid numbers studied here is between 22 and 70, while the fundamental numbers are between 40 and 86. It was found that the main chromosomal rearrangement that transforms karyotypes towards higher diploid and fundamental numbers is the acquisition of new chromosomal material via unknown mechanisms, followed by pericentric inversions that generate new chromosomal arms, centric fusions and centric fissions. In spite of their low differentiation regarding allozymic and morphological features, it was found that the karyomorphs of the Corrientes group have enough chromosomal differentiation to consider them as distinct species. Beside the range of diploid and fundamental numbers of this group (42-70 and 80-84 respectively), their pairwise chromosomal differences are high. The most closely related of them differ in one nonhomologous arm, one Robertsonian change and a whole chromosome duplication. The most differentiated taxa differ in 20 arms with lack of homology, 12 Robertsonian changes (one with monobrachial homology), six pericentric inversions and the above mentioned probable arm duplication. For these reasons, it is probable that some kind of chromosomal speciation has occurred in the Corrientes group. © 1995.
title Phylogenetic analysis of G-banded karyotypes among the South American subterranean rodents of the genus Ctenomys (Caviomorpha: Octodontidae), with special reference to chromosomal evolution and speciation
title_short Phylogenetic analysis of G-banded karyotypes among the South American subterranean rodents of the genus Ctenomys (Caviomorpha: Octodontidae), with special reference to chromosomal evolution and speciation
title_full Phylogenetic analysis of G-banded karyotypes among the South American subterranean rodents of the genus Ctenomys (Caviomorpha: Octodontidae), with special reference to chromosomal evolution and speciation
title_fullStr Phylogenetic analysis of G-banded karyotypes among the South American subterranean rodents of the genus Ctenomys (Caviomorpha: Octodontidae), with special reference to chromosomal evolution and speciation
title_full_unstemmed Phylogenetic analysis of G-banded karyotypes among the South American subterranean rodents of the genus Ctenomys (Caviomorpha: Octodontidae), with special reference to chromosomal evolution and speciation
title_sort phylogenetic analysis of g-banded karyotypes among the south american subterranean rodents of the genus ctenomys (caviomorpha: octodontidae), with special reference to chromosomal evolution and speciation
publishDate 1995
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00244066_v54_n1_p43_Ortells
http://hdl.handle.net/20.500.12110/paper_00244066_v54_n1_p43_Ortells
_version_ 1768544073026633728

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