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Vol. 46 No. 6, 2007
Molecular Characterization of Major Histocompatibility Complex Class II DQB and DRB Genes in Bottlenose Dolphins (Tursiops truncatus and T. aduncus) from the Western Pacific
Wei-Cheng Yang, Lien-Siang Chou, and Jer-Ming Hu*
Institute of Ecology and Evolutionary Biology, National Taiwan University, 1 Roosevelt Rd., Sec. 4, Taipei 106, Taiwan
Wei-Cheng Yang, Jer-Ming Hu, and Lien-Siang Chou (2007)
Variability of the major histocompatibility complex is very suitable
for investigating a wide range of open questions in evolutionary
ecology and conservation because it reflects evolutionarily relevant
and adaptive processes within and between populations. Herein, we
present the first full-length expressed DQB and DRB gene products in
the order Cetacea from 2 species of bottlenose dolphins (genus Tursiops,
family Delphinidae) of the western Pacific that differ in their diet,
microflora, and habitat. These species might represent a natural model
through which we can examine the immunogenetic consequences of
different pathogenic and environmental influences on the MHC of
mammals. Blood samples from 2 T. aduncus (from Taiwan and Indonesia) and 2 T. truncatus (from Taiwan and Japan) were used for RACE-PCR. The presence of 1 DQB locus and 2 DRB loci in this genus was revealed. The presence of TutrDQB, Tuad-DRB, and Tutr-DRB
suggests a functional role for these molecules in pathogen-specific
immune responses. However, several features do not support a
traditional role for Tuad-DQB
molecules in peptide binding, and further study is needed. The
phylogenetic analysis revealed that the sequence divergence of these 2
species might reflect different selective pressures between pathogens
in oceanic (T. truncatus) and coastal (T. aduncus)
waters. This study provides an essential foundation for analyzing
variations in MHC genes and studying infectious disease ecology in
bottlenose dolphins.
Key words: Major histocompatibility complex, Bottlenose dolphins, Tursiops.
*Correspondence:
Jer-Ming Hu and Lien-Siang Chou contributed equally to this work. Tel:
886-2-33662472. Fax: 886-2-33662473. E-mail:jmhu@ntu.edu.tw
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