Premium
Heavy‐chain variable regions in carcharhine sharks: Development of a comprehensive model for the evolution of V H domains among the gnathanstomes
Author(s) -
SHEN SHAN XIANG,
BERNSTEIN RALPH M,
SCHLUTER SAMUEL F,
MARCHALONIS JOHN J
Publication year - 1996
Publication title -
immunology and cell biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.999
H-Index - 104
eISSN - 1440-1711
pISSN - 0818-9641
DOI - 10.1038/icb.1996.63
Subject(s) - variable (mathematics) , chain (unit) , development (topology) , geography , economic geography , evolutionary biology , mathematics , biology , physics , mathematical analysis , astronomy
Summary We determined the sequence of 18 DNA clones encoding V H regions of sandbar shark and bull shark. All of these sequences exhibit key structural coding features characteristic of known V H genes of higher vertebrates. These V H sequences disclosed considerable diversity, and can be divided into six families according to the criterion of 80% DNA sequence identity. The overlapping of some V H gene clones to two or more families is a particular feature found in carcharhine sharks, which suggests that V H diversification is a continuing process. The basic sequence patterns of heavy‐chain V regions found in all representative gnathanstomes and in V H of the shark heavy immunoglobulin igW provides evidence for selection of canonical residues in all V H structures, Elasmobranch V H sequences can be divided into two classes or clans, one comprising the ‘classical’ V H set and the other comprising V H s related to those of IgW (Vω). Phylogenetic analyses place the V H cluster as the root of all the classic V H s and indicates that the Vω set is most probably that of the primordial heavy chain.