Nuclear DNA degradation during heterokaryon incompatibility in Neurospora crassa

Stephen M. Marek*, Jennifer Wu, N. Louise Glass, David G. Gilchrist, Richard M. Bostock

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

39 Scopus citations


Many filamentous fungi are capable of undergoing conspecific hyphal fusion with a genetically different individual to form a heterokaryon. However, the viability of such heterokaryons is dependent upon vegetative (heterokaryon) incompatibility (het) loci. If two individuals undergo hyphal anastomosis, but differ in allelic specificity at one or more het loci, the fusion cell is usually compartmentalized and self-destructs. Many of the microscopic features associated with vegetative incompatibility resemble apoptosis in metazoans and plants. To test the hypothesis whether vegetative incompatibility results in nuclear degradation, a characteristic of apoptosis, the cytology of hyphal fusions between incompatible Neurospora crassa strains that differed at three het loci, mat, het-c and het-6, and the cytology of transformants containing incompatible het-c alleles were examined using fluorescent DNA stains and terminal deoxynucleotidyl transferase-mediated dUTP-X nick end labeling (TUNEL). Hyphal fusion cells between het incompatible strains and hyphal segments in het-c incompatible transformants were compartmentalized by septal plugging and contained heavily degraded nuclear DNA. Hyphal fusion cells in compatible self-pairings and hyphal cells in het-c compatible transformants were not compartmentalized and rarely showed TUNEL-positive nuclei. Cell death events also were observed in senescent, older hyphae. Morphological features of hyphal compartmentation and death during vegetative incompatibility and the extent to which it is genetically controlled can best be described as a form of programmed cell death.

Original languageEnglish (US)
Pages (from-to)126-137
Number of pages12
JournalFungal Genetics and Biology
Issue number2
StatePublished - Nov 2003


  • Apoptosis
  • Fungi
  • Heterokaryon incompatibility
  • Neurospora crassa
  • Programmed cell death
  • Somatic incompatibility
  • Vegetative incompatibility

ASJC Scopus subject areas

  • Microbiology
  • Genetics

Fingerprint Dive into the research topics of 'Nuclear DNA degradation during heterokaryon incompatibility in Neurospora crassa'. Together they form a unique fingerprint.

Cite this