NEW COSMID VECTORS FOR LIBRARY CONSTRUCTION, CHROMOSOME WALKING AND RESTRICTION MAPPING IN FILAMENTOUS FUNGI

New cosmid vectors were constructed for the ascomycete fungus, Magnapo rthe grisea and the basidiomycete fungus, Ustilago maydis. These vecto rs are capable of transforming M. grisea at frequencies of up to 5 tra nsformants/mu g linear DNA and U. maydis at up to 25 transformants/mu g circular DNA for integrative transformation. In addition, 2800 trans formants/mu g DNA are possible when using an autonomously replicating vector. Since the promoters used in these vectors function in other as comycete and basidiomycete fungi, we anticipate that these vectors wil l be widely applicable.