Isoforms of the CD79 signal transduction component of the macropod B-cell receptor

B cell responses and their concomitant signal transduction pathways are not well understood in marsupial mammals, despite the availability of gene expression data for key immunoglobulin genes and for elements of the CD79a/CD79b heterodimer signalling complex for two model marsupials. Broader studies of factors that influence B cell responses are still hampered by a lack of species-specific reagents and there are few reports of other factors that influence gene expression such as the potential for splice variants in BCR components, which may influence immune signalling pathways. In this study, we characterise CD79a and CD79b genes in the endangered macropod marsupial, Onychogalea fraenata (the bridled nailtail wallaby) and show that domains and residues important for the structural and functional integrity of both monomers are conserved in this species, consistent with results previously reported for the closelyrelated macropod, Macropus eugenii (the tammar wallaby). We extend this work to report the detection of splice variants for CD79a and CD79b in wallaby species; three CD79a isoforms and one CD79b isoform. Of these, two CD79a isoforms and the CD79b isoform have not been reported in any other mammalian species.