Abstract: Objective To construct a transformation system of Cryptococcus neoformans.(C-neoformans) capsule deficient strain cap60.Methods and Results The results included:(1) A ura 5 mutant was obtained by screening the C-neoformans cap60 using 5 fluoroorotic acid counter selection method.(2) By electrotransformation and chemical transformation,the ura5 strain was successfully transformed through the plasmid pCntel1-d which contained the ura5 gene from C-neoformans as a selective marker.(3) The plasmid stability test and Southern blot analysis indicated there were two status of plasmid pCntel1-d in C-neoformans transformants:integrated or episomal plasmid.Conclusion A transformation system of C-neoformans cap60 has been established,which provides not only the basis for gene cloning from the species but also for studying gene function and gene expression.

Key words: Cryptococcus neoforman, Transformation