First record of Calomys cerqueirai (Rodentia: Phyllotini) in Espírito Santo (Brazil) with description of the 2n=36, FNA=66 karyotype
| Autor: | Valéria Fagundes, Victor Hugo Colombi |
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| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | Mammalia. 79 |
| ISSN: | 1864-1547 0025-1461 |
| DOI: | 10.1515/mammalia-2014-0076 |
| Popis: | Two karyotypes have been reported for Calomys cerqueirai: 2n=38, with 15 biarmed and three acrocentric pairs, medium submetacentric X and small acrocentric Y; and 2n=36, with no further description. Previous studies pointed out that diploid number is diagnostic at the species level in Calomys, since cryptic species have been correctly discriminated by karyotypes. Herein, we describe the 2n=36 karyotype of a specimen of C. cerqueirai from a new locality in Espirito Santo/Brazil, raising questions about the species identity and increasing the species range 140 km to the north. We used the cytb gene sequence to calculate the genetic divergence and evaluate the relationships of this specimen to other Calomys samples available. We found 0.5% genetic distance between 2n=36 and 2n=38 specimens, suggesting intraspecific variation. The 2n=36/FNA=66 karyotype is composed of 16 biarmed and one small acrocentric pairs, and one medium-sized submetacentric X pair. Comparative analysis of 2n=36/FNA=66 and 2n=38/FNA=66 suggests that centric fusion of medium acrocentrics (pairs 16 and 17 from 2n=38) originated a large submetacentric (pair 9 in 2n=36) or vice versa in a centric fission scenario. Polymorphisms in Calomys is here reported for the first time, but the proposal of species-specific karyotypes in this genus is reinforced because both 2n=36/FNA=66 and 2n=38/FNA=66 occur only in C. cerqueirai. |
| Databáze: | OpenAIRE |
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