Sequence Determination of the Heavy-Chain Constant Region in Four Immunoglobulin Classes of Mongolian Gerbils (<i>Meriones unguiculatus</i>)

Abstract

Abstract:We determined partial cDNA sequences of four immunoglobulin (Ig) classes-IgM, IgG1, IgE, and IgA-of Mongolian gerbil (Meriones unguiculatus). Each deduced Ig heavy-chain constant (IGHC) region-Cµ, Cγ1, Cε, and Cα-is structurally similar to its counterparts in the mouse and rat, and phylogenetic analysis suggests that the gerbil Igs are evolutionarily close to their counterparts. In spite of the high sequence homology to the other rodent Cγ sequences, the gerbil Cγ1 sequence differs from our previously reported Cγ2. This result indicates that the gerbil has at least two IgG subclasses. These four gerbil IGHC cDNA sequences will be useful for determining gerbil Ig isotypes and examining the expression of gerbil Ig mRNAs in response to parasitic and bacterial infections.

Isotype analysis of gerbil–mouse heterohybridomas by RT-PCR

“…In contrast, whereas expression analysis of heterohybridomas B5-3 and D5 identified Cγ2, the kit identified Cγ3. We previously determined two gerbil Cγ IGHC sequences and named them Cγ1 and Cγ2 for their homology to other rodent Cγ sequences (Ukaji et al, 2012). Gerbil Cγ2 had the highest homology to mouse Cγ2a (IgG2).…”

“…Each IGHC mRNA was amplified with specific primers (Table 1). Each gerbil IGHC primer set (for Cμ, Cγ1, Cγ2, Cε, and Cα) was designed from the cDNA sequence identified in our previous studies (Ukaji et al, 2011b(Ukaji et al, , 2012. The PCR products were electrophoresed in 1.5% agarose gels and stained with ethidium bromide.…”

“…Thus, mAbs specific to gerbil Igs would be useful for estimating humoral immunity in gerbils. We determined the cDNA sequences of genes encoding the Ig heavy-chain constant region (IGHC) of five gerbil Igs-IgM, IgG1, IgG2, IgE, and IgA (Ukaji et al, 2011b(Ukaji et al, , 2012-and established gerbil-mouse heterohybridomas that secrete gerbil mAb to keyhole limpet hemocyanin (KLH) (Ukaji et al, 2011a). Gerbil Igs secreted by heterohybridomas would be suitable as antigens for the production of mouse anti-gerbil Ig mAbs.…”

Phylogeny and Comparative Physiology of Mucosal Immunoglobulins

“…A single structural gene for IgA has been identified in three species of the eutherian order Rodentia, mouse (Mus musculus) (Auffray et al, 1981), rat (Rattus norvegicus) (unpublished; GenBank accession number AJ510151), and gerbil (Meriones unguiculatus) (Ukaji et al, 2012). Among eutherian mammalians, the gene for rodent IgA is phylogenetically most distant from the human and is closest to the corresponding IgA genes in marsupials and monotremes, suggesting a common ancestor prior to the divergence of eutherians (Figure 2).…”

Coevolution of Mucosal Immunoglobulins and the Polymeric Immunoglobulin Receptor: Evidence That the Commensal Microbiota Provided the Driving Force

“…In contrast to the platypus, only one IgA gene was identified in another monotreme, the echidna (Tachyglossus aculeatus), and in several species of marsupials [76][77][78][79][80]. Similarly, a single structural gene for IgA has been identified in 3 species of the eutherian order Rodentia, mouse (Mus musculus) [81], rat (Rattus norvegicus) (unpublished; Genbank accession number AJ510151), and gerbil (Meriones unguiculatus) [82]. By contrast, the IGH locus in the European rabbit (Oryctolagus cuniculus, order Lagomorpha) is unique among mammals, apparently having evolved from a common ancestor 6 ISRN Immunology prior to the divergence of marsupials and monotremes from eutherians.…”