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

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

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...

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Bibliographic Details
Published in:Cytogenetic and genome research Vol. 148; no. 2-3; p. 199
Main Authors: Rodrigues da Costa, Marlyson J, Siqueira do Amaral, Paulo J, Pieczarka, Julio C, Sampaio, Maria I, Rossi, Rogério V, Mendes-Oliveira, Ana C, Rodrigues Noronha, Renata C, Nagamachi, Cleusa Y
Format: Journal Article
Language:English
Published: Switzerland 01-01-2016
Subjects:
Animals
Brazil
Chromosome Inversion
Cytochromes b - genetics
Ecosystem
Evolution, Molecular
Female
Genetic Speciation
In Situ Hybridization, Fluorescence
Karyotype
Male
Phylogeny
Rivers
Rodentia - classification
Rodentia - genetics
Sex Chromosomes - genetics
Species Specificity
Translocation, Genetic
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Summary: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 = 26x2640;/27x2642;, NF = 42) for samples from the Tapajos-Xingu interfluve and cytotype B (2n = 24x2640;/25x2642;, 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 = 14x2640;/15x2640;x2642;/16x2640;/17x2642;, 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.
ISSN:1424-859X
DOI:10.1159/000446562