Molecular analysis of Cryptococcus neoformans mitochondrial cytochrome b gene sequences.
Mitochondrial cytochrome b genes (cyt b) of 40 strains of Cryptococcus neoformans were partially sequenced to determine the genetic relations. With the exception of the type strain of C. neoformans var. neoformans, all strains contained introns in their sequences. Analysis of 386 bp of coding sequence from each strain under investigation revealed a total of 27 (6.99%) variable nucleotide sites and categorized isolates of C. neoformans into nine cyt b types. C. neoformans var. gattii included cyt b types I to V, and C. neoformans var. neoformans comprised types VI to IX. cyt b types were correlated with serotypes. All strains with cyt b types I, IV, and V were serotype B. All other strains except IFM 5878 (serotype B) with cyt b types II and III were serotype C. Serotype D strains had cyt b types VI and IX, and serotype A strains were cyt b type VIII. Of four serotype AD strains, one was cyt b type VII and the remaining three were type VIII. The phylogenetic tree based on deduced amino acid sequences divided the strains only into C. neoformans var. neoformans and C. neoformans var. gattii. These results indicate that cyt b sequences are effective for DNA typing as well as phylogenetic analysis of C. neoformans.
Biswas
Swarajit Kumar
SK
Research Center for Pathogenic Fungi and Microbial Toxicoses, Chiba University, Chuo-ku, Chiba 260-8673, Japan.
Wang
Li
L
Yokoyama
Koji
K
Nishimura
Kazuko
K
D001483:Base Sequence; D003455:Cryptococcus neoformans / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D045303:Cytochromes b / Q000235:genetics*; D017931:DNA Primers; D005800:Genes, Fungal; D006801:Humans; D008928:Mitochondria / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D012703:Serotyping / Q000379:methods
D017931:DNA Primers; D045303:Cytochromes b