A versatile shuttle cosmid vector for the efficient construction of genomic libraries and for the cloning of fungal genes.

A shuttle cosmid vector, pANsCos1, has been constructed for Escherichia coli and filamentous fungi. This vector contains two cos sequences separated by a single XbaI restriction site. pANsCos1 allows the efficient construction of representative genomic libraries from as little as 15-20 micrograms of genomic DNA. Due to the presence of a functional hygromycin B phosphotransferase gene (hph) transformation of fungal protoplasts with pAN-sCos1, or derivatives of it, results in the formation of hygromycin B-resistant transformants. The T7 and T3 RNA polymerase promoter sequences flanking the cloning site, in combination with two adjacent NotI sites facilitate genomic walking and the rapid construction of restriction maps of cloned inserts.