Evolutionary Genomics of Immunoglobulin-Encoding Loci in Vertebrates

• Type of Material: Article
• Authors: Sabyasachi Das, Emory University; Masayuki Hirano, Emory University; Rea Tako, California State University Fullerton; Chelsea McCallister, California State University Fullerton; Nikolas Nikolaidis, California State University Fullerton
• Language: English
• Date: 2012-04-01
• Publisher: Bentham Science Publishers
• Publication Version: Final Published Version
• Copyright Statement: © 2012 Bentham Science Publishers.
• License: Creative Commons Attribution 2.5 Generic
• Final Published Version (URL): http://dx.doi.org/10.2174/138920212799860652
• Title of Journal or Parent Work: Current Genomics
• ISSN: 1389-2029
• Volume: 13
• Issue: 2
• Start Page: 95
• End Page: 102
• Grant/Funding Information: CM is supported by the Bradshaw Scholarship in Immunology and a grant from the FDC at California State University Fullerton (CSUF).; NN is supported by start-up funds from CSUF, a Faculty-Student research Grant from CSUPERB, and a state-mini grant from CSUF.; RT is supported by a grant from FDC at CSUF.; SD and MH are supported by a grant from the National Institute of Health (NIH) to Max D. Cooper.
• Keywords: ADAPTIVE IMMUNITY; JAWED VERTEBRATES; Antibodies; microRNA; RAJA-ERINACEA; JAWLESS VERTEBRATES; ANOLIS-CAROLINENSIS; cladistic markers; GENETICS & HEREDITY; genomic organization; BIOCHEMISTRY & MOLECULAR BIOLOGY; HEAVY-CHAIN LOCUS; CONSTANT-REGION GENES; Life Sciences & Biomedicine; comparative genomics; EUTHERIAN MAMMALS; Biochemistry & Molecular Biology; gnathostomes; Science & Technology; Genetics & Heredity; MULTIGENE FAMILIES; IMMUNE-SYSTEM
• Research Categories: Biology, General; Health Sciences, Pathology

Abstract

Immunoglobulins (or antibodies) are an essential element of the jawed vertebrate adaptive immune response system. These molecules have evolved over the past 500 million years and generated highly specialized proteins that recognize an extraordinarily large number of diverse substances, collectively known as antigens. During vertebrate evolution the diversification of the immunoglobulin-encoding loci resulted in differences in the genomic organization, gene content, and ratio of functional genes and pseudogenes. The tinkering process in the immunoglobulin-encoding loci often gave rise to lineage-specific characteristics that were formed by selection to increase species adaptation and fitness. Immunoglobulin loci and their encoded antibodies have been shaped repeatedly by contrasting evolutionary forces, either to conserve the prototypic structure and mechanism of action or to generate alternative and diversified structures and modes of function. Moreover, evolution favored the development of multiple mechanisms of primary and secondary antibody diversification, which are used by different species to effectively generate an almost infinite collection of diverse antibody types. This review summarizes our current knowledge on the genomics and evolution of the immunoglobulin-encoding loci and their protein products in jawed vertebrates.