Green Turtles (Chelonia mydas) Have Novel Asymmetrical Antibodies.
Igs in vertebrates comprise equally sized H and L chains, with exceptions such as H chain-only Abs in camels or natural Ag receptors in sharks. In Reptilia, Igs are known as IgYs. Using immunoassays with isotype-specific mAbs, in this study we show that green turtles (Chelonia mydas) have a 5.7S 120-kDa IgY comprising two equally sized H/L chains with truncated Fc and a 7S 200-kDa IgY comprised of two differently sized H chains bound to L chains and apparently often noncovalently associated with an antigenically related 90-kDa moiety. Both the 200- and 90-kDa 7S molecules are made in response to specific Ag, although the 90-kDa molecule appears more prominent after chronic Ag stimulation. Despite no molecular evidence of a hinge, electron microscopy reveals marked flexibility of Fab arms of 7S and 5.7S IgY. Both IgY can be captured with protein G or melon gel, but less so with protein A. Thus, turtle IgY share some characteristics with mammalian IgG. However, the asymmetrical structure of some turtle Ig and the discovery of an Ig class indicative of chronic antigenic stimulation represent striking advances in our understanding of immunology.
U.S. Geological Survey, National Wildlife Health Center-Honolulu Field Station, Honolulu, HI 96850; thierry_work@usgs.gov.
Thierry M
http://orcid.org/0000-0002-4426-9090
TM
Work
U.S. Geological Survey, National Wildlife Health Center-Honolulu Field Station, Honolulu, HI 96850;
Julie
http://orcid.org/0000-0001-5560-9946
J
Dagenais
U.S. Geological Survey, National Wildlife Health Center-Honolulu Field Station, Honolulu, HI 96850;
Renee
R
Breeden
Nano-Imaging Services, Inc., San Diego, CA 92121;
Anette
A
Schneemann
Nano-Imaging Services, Inc., San Diego, CA 92121;
Joyce
J
Sung
Microbiology, Math Science Department, Kapiolani Community College, Honolulu, HI 96816; and.
Brian
B
Hew
National Marine Fisheries Service, Pacific Islands Fisheries Science Center, Honolulu, HI 96818.
George H
GH
Balazs
Microbiology, Math Science Department, Kapiolani Community College, Honolulu, HI 96816; and.
John M
JM
Berestecky
D000818:Animals; D000906:Antibodies / Q000276:immunology; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000276:immunology; D000941:Antigens / Q000276:immunology; D007091:Image Processing, Computer-Assisted; D007143:Immunoglobulin Heavy Chains / Q000276:immunology; D007132:Immunoglobulin Isotypes / Q000276:immunology*; D007147:Immunoglobulin Light Chains / Q000276:immunology; D007136:Immunoglobulins / Q000276:immunology* / Q000648:ultrastructure*; D046529:Microscopy, Electron, Transmission / Q000662:veterinary; D008969:Molecular Sequence Data; D011961:Receptors, Fc / Q000276:immunology; D014426:Turtles / Q000276:immunology*
D000906:Antibodies; D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D000941:Antigens; C016512:IgY; D007143:Immunoglobulin Heavy Chains; D007132:Immunoglobulin Isotypes; D007147:Immunoglobulin Light Chains; D007136:Immunoglobulins; D011961:Receptors, Fc