Cross-Reactivity between Immunoglobulin G Antibodies of Whales and Dolphins Correlates with Evolutionary Distance

• Published in: Clinical and Vaccine Immunology
• Main Authors: Nollens, Hendrik H., Ruiz, Carolina, Walsh, Michael T., Gulland, Frances M. D., Bossart, Gregory, Jensen, Eric D., McBain, James F., Wellehan, James F. X.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Society for Microbiology 2008
• Subjects: baleen whale; Killer Whale; Orca; Orcinus orca; toothed whales; Killer whale
• Online Access: http://dx.doi.org/10.1128/cvi.00219-08; https://journals.asm.org/doi/pdf/10.1128/CVI.00219-08

ABSTRACT Growing morphological and molecular evidence indicates that the porpoises, dolphins, and whales evolved within the even-toed ungulates, formerly known as Artiodactyla. These animals are now grouped in the Cetartiodactyla. We evaluated the antigenic similarity of the immunoglobulin G (IgG) molecules of 15 cetacean species and the domestic cow. The similarity was scored using three distinct antibodies raised against bottlenose dolphin ( Tursiops truncatus ) IgG in a Western blot, an indirect enzyme-linked immunosorbent assay (ELISA), and a competitive ELISA format. A score was generated for the genetic distance between each species and T. truncatus using the cytochrome b sequence. Each antibody displayed a distinct pattern of reactivity with the IgG antibodies of the various species. The monoclonal antibody (MAb) specific for the γ heavy chain of T. truncatus was reactive with all monodontids, delphinids, and phocoenids. The light-chain-specific MAb reacted with IgG of delphinoid and phocoenid species and one of the two mysticete species tested. The polyclonal antibody was broadly cross-reactive across all cetaceans and the domestic cow. Using the MAb specific for the γ heavy chain, the degree of IgG cross-reactivity ranged from less than 17% for the mysticetes to 106% for killer whale Orcinus orca . The IgG in beaked whale and baleen whale sera was significantly less cross-reactive with bottlenose dolphin IgG than sera from other toothed whales. A strong negative correlation was demonstrated between antigenic cross-reactivity of IgG molecules and the genetic distance of their hosts. The data generated will be useful for the development of clinical serodiagnostics in diverse cetacean species.