Immunoglobulin D (IgD) is an ancient antibody with dual membrane-bound and fluid-phase
antigen receptor functions. The biology of secreted IgD remains elusive. Here, we …

Immunoglobulin D (IgD) has remained a mysterious antibody class for almost half a century.
IgD was initially thought to be a recently evolved Ig isotype expressed only by some …

Recent discoveries of IgD in ancient vertebrates suggest that IgD has been preserved in
evolution from fish to human for important immunological functions. A non-canonical form of …

IgD emerged soon after IgM at the time of inception of the adaptive immune system. Despite
its evolutionary conservation from fish to humans, the specific functions of IgD have only …

The gene encoding IgH δ has been found in all species of teleosts studied to date. However,
catfish (Ictalurus punctatus) is the only species of fish in which a secretory form of IgD has …

IgD, previously thought to be a recent addition to the immunoglobulin classes, has long
been considered an enigmatic molecule. For example, it was debated if IgD had a specific …

Channel catfish Ictalurus punctatus express two Ig isotypes: IgM and IgD. Although catfish
IgM has been extensively studied at the functional and structural levels, much less is known …

Teleost fish are the most primitive bony vertebrates that contain immunoglobulins. In contrast
to mammals and birds, these species are devoid of immunoglobulin A (IgA) or a functional …

Immunoglobulins (Igs) are complex glycoproteins that play critical functions in innate and
adaptive immunity of all jawed vertebrates. Given the unique characteristics of mucosal …

Recent years have witnessed a renaissance in the study of fish immune systems. Such
studies have greatly expanded the knowledge of the evolution and diversification of …