Difference in FKS1 gene sequences between serotypes A and D of Cryptococcus neoformans

Abstract

We compared sequences of the glucan synthase (FKS1) gene in serotypes A and D of Cryptococcus neoformans. Four introns were present in serotype D but not serotype A. PCR with primers that flank these introns permits simple differentiation of serotypes A and D.

FIG. 1.

Sequences and positions of four introns in FKS1 of JEC 21 (serotype D). Positions are relative to the sequence of GenBank accession number AF102882.

FIG. 2.

PCR fragment of the FKS1 gene including the introns found in serotype D. (a) Fragments amplified from cDNA and genomic DNA. (b) Electrophoretic profiles of the predicted 1,003-bp fragment amplified with primers GS and Ha. (c) Southern hybridization of the gel in panel b with serotype A-specific probe. (d) Southern hybridization of the gel in panel b with serotype D-specific probe.