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- First report of major histocompatibility complex class II loci from the Amazon pink river dolphin (genus Inia)
- M. Martínez-Agüero1, S. Flores-Ramírez2 and M. Ruiz-García1
- 1Unidad de Genética (Grupo de Genética de Poblaciones Molecular y Biología Evolutiva),
- Departamento de Biología, Facultad de Ciencias, Pontifica Universidad Javeriana,
- Bogotá, DC, Colombia
- 2Laboratorio de Ecología Molecular y Genética Aplicada a la Conservación,
- Departamento de Biología Marina, Área de Ciencias del Mar,
- Universidad Autónoma de Baja California Sur, La Paz, Baja California Sur, Mexico
- Corresponding author: M. Ruiz-García
- E-mail: [email protected]
- Genet. Mol. Res. 5 (3): 421-431 (2006)
- Received December 7, 2005
- Accepted June 9, 2006
- Published July 3, 2006
ABSTRACT. We report the first major histocompatibility complex (MHC) DQB1 sequences for the two species of pink river dolphins (Inia geoffrensis and Inia boliviensis) inhabiting the Amazon and Orinoco River basins. These sequences were found to be polymorphic within the Inia genus and showed shared homology with cetacean DQB-1 sequences, especially, those of the Monodontidae and Phocoenidae. On the other hand, these sequences were shown to be divergent from those described for other riverine dolphin species, such as Lipotes vexillifer, the Chinese river dolphin. Two main conclusions can be drawn from our results: 1) the Mhc DQB1 sequences seem to evolve more rapidly than other nuclear sequences in cetaceans, and 2) differential positive selective pressures acting on these genes cause concomitant divergent evolutionary histories that derive phylogenetic reconstructions that could be inconsistent with widely accepted intertaxa evolutionary relationships elucidated with other molecular markers subjected to a neutral dynamics.
Key words: Mhc DQB1 sequences, Inia, Molecular evolution, River dolphins
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