Characterization of the immunoglobulin A heavy chain gene of the Atlantic bottlenose dolphin (Tursiops truncatus).

Immunoglobulin constant region heavy chain genes of the dolphin (Tursiops truncatus) have been described for IgM and IgG but not for IgA. Here, the heavy chain sequence of dolphin IgA has been cloned and sequenced as cDNA. RT-PCR amplification from blood peripheral lymphocytes was carried out using degenerate primers and a single sequence was detected.

Enhancer and promoter activity in the JH to IGHM intron of the Pekin duck, Anas platyrhynchos.

A transcriptional enhancer, Emu, was defined in the IGH locus of the Pekin duck, Anas platyrhynchos. Regions of DNA from the JH to IGHM intron were cloned into reporter constructs containing the SV40 promoter and transiently transfected into chicken B and T lymphocytes. A strong transcriptional activity, of several hundred-fold greater than that of a reporter construct with the promoter alone, was localized to a 281bp region that contains 2 E-box motifs, CAGCTG.

The Immunoglobulin G Heavy Chain (IGHG) genes of the Atlantic bottlenose dolphin, Tursiops truncatus.

Dolphin Immunoglobulin G Heavy Chain (IGHG) sequences were obtained by PCR amplification of cDNA from peripheral blood leukocytes using degenerate primers. Analysis of full-length sequences indicated the presence of two expressed isotypes, IGHG1 and IGHG2 that differ mainly in the hinge region of the molecule. Genomic Southern blot analysis indicated that the IGHG1 and IGHG2 genes are most likely present in single copies.

Evolution of antibody class switching: identification and transcriptional control of an Inu exon in the duck (Anas platyrhynchos).

Immunoglobulin class switching is characteristic to the tetrapod lineage, but the nature of this process has been elucidated only in mammals, where I-exon transcription initiates and directs the recombination in the IgH locus. Here, it is shown that an I-exon occurs 5' of the nu (IgY constant region) gene of the duck (Anas platyrhynchos): it is longer than mammalian I-exons and comprised primarily of tandem repeats. The Inu promoter was identified and shown to be responsive to stimulation with IL-4 but not LPS.

Immunoglobulins of the non-galliform birds: antibody expression and repertoire in the duck.

Galliform and non-galliform birds express three immunoglobulin isotypes, IgM, IgA and IgY. Beyond this we should not generalize because differences in gene organization may have functional consequences reflected in the immune response. At present, studies on non-galliform birds are largely restricted to ducks.

Regulation of immunoglobulin gene transcription in a teleost fish: identification, expression and functional properties of E2A in the channel catfish.

The function of the transcriptional enhancer, Emu3', of the IgH locus of the channel catfish, Ictalurus punctatus, involves the interaction of E-protein and Oct family transcription factors. The E-proteins [class I basic helix-loop-helix (bHLH) family] are encoded in mammals by three genes: E2A (of which E12/E47 are alternatively spliced products), HEB, and E2-2. An E2A homologue has been identified in a catfish B-cell cDNA library and contains regions homologous to the bHLH and activation domains of mammalian and other vertebrate E2A proteins.

Evolution of transcriptional control of the IgH locus: characterization, expression, and function of TF12/HEB homologs of the catfish.

The transcriptional enhancer (Emu3') of the IgH locus of the channel catfish, Ictalurus punctatus, differs from enhancers of the mammalian IgH locus in terms of its position, structure, and function. Transcription factors binding to multiple octamer motifs and a single muE5 motif (an E-box site, consensus CANNTG) interact for its function. E-box binding transcription factors of the class I basic helix-loop-helix family were cloned from a catfish B cell cDNA library in this study, and homologs of TF12/HEB were identified as the most highly represented E-proteins.

Enhanced bacterial disease resistance of transgenic channel catfish Ictalurus punctatus possessing cecropin genes.

The cecropin B gene from the moth Hyalophora cecropia, driven by the cytomegalovirus promoter, was transferred to the channel catfish Ictalurus punctatus. Transgenic individuals (P1) were mated to produce individuals (F1) that exhibited enhanced disease resistance and survival when challenged with pathogenic bacteria. During the epizootic of Flavobacterium columnare in an earthen pond, the percentage of transgenic individuals containing preprocecropin B construct that survived (100%) was significantly greater (P <0.

Oct2 transcription factor of a teleost fish: activation domains and function from an enhancer.

Oct2 transcription factors of the catfish (Ictalurus punctatus) are expressed as alternatively spliced alpha and beta isoforms. Functional analysis revealed an N-terminal glutamine (Q)-rich transactivation domain common to both isoforms of catfish Oct2. A C-terminal proline, serine, threonine (PST)-rich activation domain was identified exclusively in the beta isoform.

Cloning of the IgM heavy chain of the bottlenose dolphin (Tursiops truncatus), and initial analysis of VH gene usage.

Clones encoding the dolphin IgM heavy (micro) chain gene were isolated from a cDNA library of peripheral blood leukocytes. Genomic Southern blot analyses showed that the dolphin IGHM gene is most likely present in a single copy, and its sequence shows greatest similarity to those of the IGHM gene of the sheep, pig and cow, evolutionarily related artiodactyls. The transmembrane (TM) form of the IGHM chain was isolated by 3' RACE.