New cosmid vectors for library construction, chromosome walking and restriction mapping in filamentous fungi.

New cosmid vectors were constructed for the ascomycete fungus, Magnaporthe grisea and the basidiomycete fungus, Ustilago maydis. These vectors are capable of transforming M. grisea at frequencies of up to 5 transformants/micrograms linear DNA and U. maydis at up to 25 transformants/microgram circular DNA for integrative transformation. In addition, 2800 transformants/microgram DNA are possible when using an autonomously replicating vector. Since the promoters used in these vectors function in other ascomycete and basidiomycete fungi, we anticipate that these vectors will be widely applicable.