OF ORPHONS AND UHOS - DELIMITATION OF THE GERMLINE REPERTOIRE OF HUMAN-IMMUNOGLOBULIN KAPPA GENES

Two problems in defining the germline repertoire of immunoglobulin kappa-genes were investigated. One concerns putative transposed V(kappa) genes (orphans), the other one weak hybridization signals which may or may not turn out to be V(kappa) genes (UHOs). It was shown by sequencing that the three V(kappa) genes Z2, Z3 and Z4 are very closely related to the Z1 and V118 genes and to two other genes which had been localized on chromosomes 1 and 22, i.e. outside the kappa-locus on chromosome 2. It is therefore likely that also the Z2-Z4 genes are orphans and not part of the kappa-locus. Two UHOs turned out not to contain V(kappa)- like structures. This together with previous results makes it likely that we have detected all germline V(kappa) genes with the available hybridization probes.