Visualization of a conditionally dispensable chromosome in the filamentous ascomycete Nectria haematococca by fluorescence in situ hybridization

Masatoki Taga, Minoru Murata, Hans D. Vanetten

Research output: Contribution to journalArticle

26 Citations (Scopus)


Supernumerary chromosomes, termed 'conditionally dispensable' (CD) chromosomes, are known in Nectria haematococca. Because these CD chromosomes had been revealed solely by pulsed-field gel electrophoresis, their morphological properties were unknown. In this study, we visualized a 1.6-Mb CD chromosome of this fungus by three different types of fluorescence in situ hybridization. The CD chromosome at mitotic metaphase was similar in its appearance to the other chromosomes in the genome. Heterochromatic condensation was not distinct in the CD chromosome, suggesting that it is primarily euchromatic. It was also evident that the CD chromosome is unique and not a duplicate of other chromosomes in the genome. At interphase and prophase, the CD chromosome was not dispersed throughout the nucleus, but occupied a limited domain. Occasionally, occurrence of two distinct unattached copies of the CD chromosome were observed during interphase and metaphase.

Original languageEnglish
Pages (from-to)169-177
Number of pages9
JournalFungal Genetics and Biology
Issue number3
Publication statusPublished - Apr 1999



  • B chromosome
  • Conditionally dispensable chromosome
  • Supernumerary chromosome

ASJC Scopus subject areas

  • Genetics
  • Microbiology

Cite this