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Structure of the catfish IGH locus: analysis of the region including the single functional IGHM gene
- Source :
- Immunogenetics. 58:831-844
- Publication Year :
- 2006
- Publisher :
- Springer Science and Business Media LLC, 2006.
-
Abstract
- The catfish IGH locus is large ( approximately 1 Mb) and complex, having undergone multiple internal duplications and transpositions. To define the structure of the locus that contains the single expressed IGHM gene, two overlapping bacterial-artificial-chromosome (BAC) clones spanning the most 3' end of the channel catfish immunoglobulin heavy (IGH) chain locus have been completely sequenced. The analyses created a contig of 257,153 bp containing 55 VH, 6 D, 12 JH genes and the IGH constant region genes encoding the functional secreted and membrane forms of IgM and the membrane form of IgD. This analysis revealed three major features. First, no C-region genes were found aside from the previously described IGHM1 and IGHD1, with the latter gene being the most 3' C-region gene of the catfish IGH locus. There was no evidence in the region sequenced for genes that could encode an Ig class similar to the IgZ/IgT described in zebrafish, trout and pufferfish. Second, there are a high number of VH pseudogenes, 28 out of 55 (51%). In contrast, the entire zebrafish IGH locus has 40 functional VH genes and eight pseudogenes (17%). Third, an internal duplication of a 52.4-kb block of VH genes has occurred. These observations suggest that the IGH locus of teleost fish varies significantly from species to species in the diversity of C-region genes as well as the numbers of genes encoding V regions.
- Subjects :
- Chromosomes, Artificial, Bacterial
Genes, Immunoglobulin Heavy Chain
Pseudogene
Molecular Sequence Data
Immunology
Gene Dosage
Immunoglobulin Variable Region
Locus (genetics)
Biology
Gene dosage
Gene duplication
Genetics
Animals
Amino Acid Sequence
Gene
Phylogeny
Base Sequence
Contig
Immunoglobulin mu-Chains
Molecular biology
Ictaluridae
Immunoglobulin Joining Region
Immunoglobulin heavy chain
Sequence Alignment
Pseudogenes
Catfish
Subjects
Details
- ISSN :
- 14321211 and 00937711
- Volume :
- 58
- Database :
- OpenAIRE
- Journal :
- Immunogenetics
- Accession number :
- edsair.doi.dedup.....17800f2b7111ca102182a8ce02e1d06b