Transposition of human immunoglobulin V kappa genes within the same chromosome and the mechanism of their amplification.
The variable, joining and constant gene segments of the human immunoglobulin kappa locus (V kappa, J kappa and C kappa) are located on the short arm of chromosome 2 at 2p11-2p12. Here we describe a cluster of 11 V kappa genes on the long arm of chromosome 2 at 2cen-q11. By pulsed-field gel electrophoresis, cosmid cloning and DNA sequencing the cluster was shown to consist of four amplified units (amplicons). The amplicons, each 110-160 kb in size, are organized within 650 kb as an array of inverted repeats with short stretches of non-amplified DNA in between. Cloning and sequencing of three different joints between amplified and non-amplified DNA revealed the existence of parts of Alu repeats at each of the analysed joints. It is suggested that during evolution a group of five V kappa genes was transposed from the short to the long arm of chromosome 2 by a pericentric inversion. Three of the five V kappa genes were then amplified in two subsequent steps to yield the structure found in the majority of the present day population. The possible relation of this structure to a pericentric inversion of chromosome 2 that is seen cytogenetically in a small fraction of today's population is discussed.
Zimmer
F J
FJ
Institut für Physiologische Chemie, Universität München, Ulm, FRG.
Hameister
H
H
Schek
H
H
Zachau
H G
HG
D001483:Base Sequence; D002874:Chromosome Mapping; D002889:Chromosomes, Human, Pair 2; D003001:Cloning, Molecular; D004587:Electrophoresis, Agar Gel; D005784:Gene Amplification; D015321:Gene Rearrangement; D005803:Genes, Immunoglobulin / Q000235:genetics*; D015894:Genome, Human; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D008969:Molecular Sequence Data; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
D007145:Immunoglobulin kappa-Chains