of choice and may be derived from genes encoding proteins either homologous or heterologous to the host cell for transcription in a fungal host examples of useful promoters are those derived from the gene encoding a oryzae taka amylase rhizomucor miehei aspartic proteinase a niger neutral u03b1 amylase a niger acid stable u03b1 amylase a niger or a awamori glucoamylase glaa rhizomucor miehei lipase a oryzae alkaline protease a oryzae triose phosphate isomerase or a nidulans acetamidase preferred are the taka amylase and glaa promoters the expression vector of the invention may also comprise a suitable transcription terminator and in eukaryotes polyadenylation sequences operably connected to the dna sequence encoding the heterologous gene sequence termination and polyadenylation sequences may suitably be derived from the same sources as the promoter the vector may further comprise a dna sequence enabling the vector to replicate in the host cell in question examples of such sequences are the origins of replication of plasmids puc19 pacyc177 pub110 pe194 pamb1 and pij702 the vector may also comprise a selectable marker e g a gene the product of which complements a defect in the host cell or one which confers antibiotic resistance such as ampicillin kanamycin chloramphenicol or tetracycline resistance examples of aspergillus selection markers include amds pyrg argb niad sc and hygb a marker giving rise to hygromycin resistance preferred for use in an aspergillus host cell are the amds and pyrg markers of a nidulans or a oryzae furthermore selection may be accomplished by co transformation e g as described in wo 91 17243 it is generally preferred that the expression gives rise to a product which is extracellular the protein of interest may thus comprise a preregion permitting secretion of the expressed protein into the.