HYBRID-GENE CASSETTE VECTOR

摘要

A cassette vector for use in constructing a hybrid Ai-B' gene where (a) Ai is a polymorphic coding region derived from an Ai-Bi gene in a family of polymorphic A-B genes; (b) B' is derived from a selected A'-B' gene; (c) Ai and A' and Bi and B' are structurally and functionally homologous gene coding regions; and (d) the A and B coding regions and the A' and B' coding regions are separated by introns I and I', respectively. The vector includes a selectable-marker gene which permits selection in a host of a cloning vector which acquires the marker gene by recombination with the cassette vector, the B' coding regions, and, located adjacent the 5' end of said B' coding region, a gene fragment derived from intron I in one of the genes in the A-B gene family. Introduction of the vector, and a library of genomic DNA fragments containing an Ai-intron gene fragment into a recombination permissive host leads to a recombination event which produces the desired Ai-B' gene. A cloning vector containing the hybrid gene is readily selectable by the presence of the cassette vector's selectable marker incorporated into the cloning vector by the recombination event. A lambda phage cloning vector useful for constructing genomic DNA libraries for use with the cassette vectors is also provided.