Developmentally controlled and tissue-specific expression of unrearranged VH gene segments. Cell. 1985. 40: 271-281.

摘要

Immunoglobulin (Ig) heavy and light chain variable region genes are somatically assembled from multiple germ-line gene segments during the early stages of the B lymphocyte differentiation pathway (see review by Tonegawa, 1983). The first cell in this pathway to produce detectable Ig is the cytoplasmic ^-positive pre-B cell (Levitt and Cooper, 1980; Siden et al., 1981), which has rearranged its heavy chain genes but not its light chain genes (Coff-man and Weissman, 1983); it is found in fetal liver and in adult bone marrow. Heavy chain gene assembly initiates with the joining of a diversity (D) segment to a joining (JH) segment to form a DJH complex; this occurs on both chromosomes and is followed by the appendage of an upstream variable (VH) segment to form a complete VHDJH variable region gene (Alt et al., 1984). Light chain (kappa and lambda) rearrangement generally occurs only after heavy chain gene assembly is complete (Maki et al., 1980; Perry et al., 1981; Alt et al., 1981) and consists of the joining of a VL segment to a JL segment.