Skip to main content

Some NLM-NCBI services and products are experiencing heavy traffic, which may affect performance and availability. We apologize for the inconvenience and appreciate your patience. For assistance, please contact our Help Desk at info@ncbi.nlm.nih.gov.

Journal of Bacteriology logoLink to Journal of Bacteriology
. 1982 Jun;150(3):1292–1296. doi: 10.1128/jb.150.3.1292-1296.1982

Genetic and phenotypic characterization of capsule mutants of Cryptococcus neoformans.

E S Jacobson, D J Ayers, A C Harrell, C C Nicholas
PMCID: PMC216353  PMID: 7042689

Abstract

Stable mutants with reduced capacity to produce capsules were isolated from suspensions of Cryptococcus neoformans after treatment of the wild type with a mutagen. The mutants could be assigned one of two phenotypes, hypocapsular or acapsular. Hypocapsular mutants were immunochemically and physicochemically indistinguishable from the wild type, whereas acapsular mutants lacked a major capsular antigen and a negatively charged exterior. In genetic analysis, the mutant trait segregated as a Mendelian gene (1:1) when random basidiospores from an outcross were studied, and analysis of products of single meiotic events from outcrossed mutants was likewise consistent with meiotic segregation. Two-factor crosses yielded the expected four classes of progeny, with recombinants equal to parentals. We concluded that chromosomal genes are responsible for synthesis of the cryptococcal capsule and that random basidiospore analysis represents a useful technique for genetic analysis in this species.

Full text

PDF
1292

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bulmer G. S., Sans M. D. Cryptococcus neoformans. II. Phagocytosis by human leukocytes. J Bacteriol. 1967 Nov;94(5):1480–1483. doi: 10.1128/jb.94.5.1480-1483.1967. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bulmer G. S., Sans M. D., Gunn C. M. Cryptococcus neoformans. I. Nonencapsulated mutants. J Bacteriol. 1967 Nov;94(5):1475–1479. doi: 10.1128/jb.94.5.1475-1479.1967. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Cherniak R., Reiss E., Slodki M. E., Plattner R. D., Blumer S. O. Structure and antigenic activity of the capsular polysaccharide of Cryptococcus neoformans serotype A. Mol Immunol. 1980 Aug;17(8):1025–1032. doi: 10.1016/0161-5890(80)90096-6. [DOI] [PubMed] [Google Scholar]
  4. Jacobson E. S., Ayers D. J. Auxotrophic mutants of Cryptococcus neoformans. J Bacteriol. 1979 Jul;139(1):318–319. doi: 10.1128/jb.139.1.318-319.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Kline M. T., Jacobson E. S. Auxotrophic markers and the cytogenetics of Filobasidiella neoformans. Mycopathologia. 1981 Nov 11;76(2):115–117. doi: 10.1007/BF00443758. [DOI] [PubMed] [Google Scholar]
  6. Kozel T. R., Cazin J., Jr Induction of humoral antibody response by soluble polysaccharide of Cryptococcus neoformans. Mycopathol Mycol Appl. 1974 Oct 15;54(1):21–30. doi: 10.1007/BF02055969. [DOI] [PubMed] [Google Scholar]
  7. Kozel T. R., Cazin J. Nonencapsulated Variant of Cryptococcus neoformans I. Virulence Studies and Characterization of Soluble Polysaccharide. Infect Immun. 1971 Feb;3(2):287–294. doi: 10.1128/iai.3.2.287-294.1971. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Kozel T. R. Non-encapsulated variant of Cryptococcus neoformans. II. Surface receptors for cryptococcal polysaccharide and their role in inhibition of phagocytosis by polysaccharide. Infect Immun. 1977 Apr;16(1):99–106. doi: 10.1128/iai.16.1.99-106.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Kozel T. R., Reiss E., Cherniak R. Concomitant but not causal association between surface charge and inhibition of phagocytosis by cryptococcal polysaccharide. Infect Immun. 1980 Aug;29(2):295–300. doi: 10.1128/iai.29.2.295-300.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Kwon-Chung K. J. A new genus, filobasidiella, the perfect state of Cryptococcus neoformans. Mycologia. 1975 Nov-Dec;67(6):1197–1200. [PubMed] [Google Scholar]
  11. Kwon-Chung K. J. Morphogenesis of Filobasidiella neoformans, the sexual state of Cryptococcus neoformans. Mycologia. 1976 Jul-Aug;68(4):821–833. [PubMed] [Google Scholar]
  12. Kwon-Chung K. J. Nuclear genotypes of spore chains in Filobasidiella neoformans (Cryptococcus neoformans). Mycologia. 1980 Mar-Apr;72(2):418–422. [PubMed] [Google Scholar]
  13. LITTMAN M. L., TSUBURA E. Effect of degree of encapsulation upon virulence of Cryptococcus neoformans. Proc Soc Exp Biol Med. 1959 Aug-Sep;101:773–777. doi: 10.3181/00379727-101-25090. [DOI] [PubMed] [Google Scholar]
  14. Rhodes J. C., Howard D. H. Isolation and characterization of arginine auxotrophs of Cryptococcus neoformans. Infect Immun. 1980 Mar;27(3):910–914. doi: 10.1128/iai.27.3.910-914.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Journal of Bacteriology are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES