Molecular characterization of expressed DQA and DQB genes in the California sea lion ( Zalophus californianus )
| Autor: | William Van Bonn, Brian Aldridge, Frances M. D. Gulland, Robert L. DeLong, Michael L. Johnson, Jeffrey L Stott, Lizabeth Bowen, Jennifer C. Woo |
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| Rok vydání: | 2002 |
| Předmět: |
Zalophus californianus
Pseudogene Molecular Sequence Data Immunology Population Genes MHC Class I Peptide binding Biology Major histocompatibility complex California Species Specificity Genetic variation Genetics Animals Genetic Predisposition to Disease education Gene Alleles education.field_of_study Base Sequence Genetic Variation biology.organism_classification Null allele Sea Lions Vertebrates biology.protein Pseudogenes |
| Zdroj: | Immunogenetics. 54:332-347 |
| ISSN: | 1432-1211 0093-7711 |
| Popis: | To date, there are no published MHC sequences from the California sea lion (Zalophus californianus), a thriving species that, by feeding high on the marine food web, could be a sentinel for disturbances in marine and coastal ecosystems. In this study, degenerate primers and RACE technology were used to amplify near-full-length (MhcZaca- DQB) and full-length (MhcZaca- DQA) expressed class II MHC gene products from the peripheral blood mononuclear cells of two California sea lions in rehabilitation. Five unique Zaca- DQA sequences and eight unique Zaca- DQB sequences, all encoding functional proteins, were identified in the two animals, indicating the presence of multiple DQ- loci in this species. An additional three Zaca- DQB sequences containing features compatible with pseudogenes or null alleles were also identified. Despite the identification of multiple DQA and DQB sequences, the degree of heterogeneity between them was extremely low. To confirm the limited degree of Zaca-DQ nucleotide variation between individuals, we used denaturing gradient gel electrophoresis to examine putative peptide binding region sequences from the peripheral blood leukocyte-derived RNAs of 19 wild-caught California sea lions from physically distinct populations. The pattern of Zaca-DQ sequence migration was identical between individuals and independent of geographical region. This apparent Zaca-DQ sequence identity between sea lions was confirmed by direct sequencing of individual bands. In combination, these findings raise important questions regarding immunogenetic diversity within this thriving species, and should prompt further research into the existence of a highly polymorphic sea lion class II MHC molecule with sequence features that support traditional peptide binding functions. |
| Databáze: | OpenAIRE |
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