Immunoglobulin D

Shortened to IgD

IgD

IgD - B. Catchpole, RVC 2008

IgD is present in ruminants, pigs, (dogs) and rodents but has not been identified in horses, cats, rabbits and chickens. It is mainly expressed on the surface of B-cells i.e. it is never secreted.

Structure

IgD is Y-shaped and in rodents it has two heavy chain constant regions, whereas other mammals have three. IgD has a long hinge region and no disulfide bonds.

Function

• IgD is only expressed in association with IgM
• It is important in B-cell development.

---

^{Immunoglobulins: Immunoglobulin A, Immunoglobulin D, Immunoglobulin E, Immunoglobulin G & Immunoglobulin M}