The immune system is composed of two subsystems—the innate immune system and the
adaptive immune system. The innate immune system is the first to respond to pathogens and …

The adaptive immune system arose 500 million years ago in ectothermic (cold-blooded)
vertebrates. Classically, the adaptive immune system has been defined by the presence of …

The B cell receptor and secreted antibody are at the nexus of humoral adaptive immunity. In
this review, we summarize what is known of the immunoglobulin genes of jawed …

IgD has remained a mysterious Ig class and a bane to immunology students since its
discovery> 40 years ago. Its spotty occurrence in mammals and birds and the discovery of …

This review discusses evolution of the process of Ig heavy chain class switching, relating it to
the first appearance of somatic hypermutation (SHM) of variable region genes. First, we …

In addition to antibodies with the classical composition of heavy and light chains, the
adaptive immune repertoire of sharks also includes a heavy-chain only isotype, where …

Immunoglobulins (Igs), as one of the hallmarks of adaptive immunity, first arose
approximately 500 million years ago with the emergence of jawed vertebrates. Two events …

Background Shark new antigen receptor variable domain (VNAR) antibodies can bind
restricted epitopes that may be inaccessible to conventional antibodies. Methods Here, we …

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 …

The cartilaginous fish are the oldest phylogenetic group in which all of the molecular
components of the adaptive immune system have been found. Although early studies clearly …