CIp10, an efficient and convenient integrating vector for <i>Candida albicans</i>

Abstract

Candida albicans is the major fungal pathogenin humans (Odds, 1994). Despite its medicalimportance, the molecular dissection of thisfungus has progressed relatively slowly. This isbecause (a) it is diploid, (b) a sexual cycle has notbeen elaborated, and (c) the alternative usage ofthe CTG codon renders most reporter genes non-functional (Santos et al., 1993; Magee, 1998). TheC. albicans molecular toolbox has expandedsignificantly within the last 10 years, thanks tothe development of auxotrophic markers, genomicand cDNA libraries, a robust gene disruptiontechnology, specialized reporter genes and regula-table promoters (Smith et al., 1992; Fonzi andIrwin, 1993; Swoboda et al., 1993; Pla et al., 1996;Srikantha et al., 1996; Cormack et al., 1997;Leuker et al., 1997; Care et al., 1999). Further-more, the isolation of C. albicans genes has beenfacilitated by rapid advancements in C. albicansgenome mapping and sequencing (Tait et al.,1997; Chibana et al., 1998; Magee, 1998; http://alces.med.umn.edu:80/bin/genelist?seqs). How-ever, a limited number of reliable and robustplasmids are available to support genetic screensand functional analyses in C. albicans. Here wedescribe a convenient and efficient integratingvector for C. albicans.Most plasmids transform C. albicans veryinefficiently, and genes carried on these vectorstend to be expressed inefficiently (see e.g. Baileyet al., 1996). Also, episomal plasmids tend torearrange or are unstable in C. albicans (Pla et al.,1996). Therefore, we constructed the vector CIp10(Candida integrating plasmid 10). The plasmid isbased on pBluescript KS