Inactivation of the HR6B ubiquitin-conjugating DNA repair enzyme in mice causes male sterility associated with chromatin modification

Cell. 1996 Sep 6;86(5):799-810. doi: 10.1016/s0092-8674(00)80154-3.


The ubiquitin-conjugating yeast enzyme RAD6 and its human homologs hHR6A and hHR6B are implicated in postreplication repair and damage-induced mutagenesis. The yeast protein is also required for sporulation and may modulate chromatin structure via histone ubiquitination. We report the phenotype of the first animal mutant in the ubiquitin pathway: inactivation of the hHR6B-homologous gene in mice causes male infertility. Derailment of spermatogenesis becomes overt during the postmeiotic condensation of chromatin in spermatids. These findings provide a parallel between yeast sporulation and mammalian spermatogenesis and strongly implicate hHR6-dependent ubiquitination in chromatin remodeling. Since heterozygous male mice and even knockout female mice are completely normal and fertile and thus able to transmit the defect, similar hHR6B mutations may cause male infertility in man.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Apoptosis
  • Body Weight
  • Chromatin / metabolism*
  • Chromosomal Proteins, Non-Histone / analysis
  • DNA Repair
  • Female
  • Histones / analysis
  • Humans
  • Infertility, Male / genetics*
  • Ligases / genetics*
  • Male
  • Mice
  • Mice, Knockout
  • Molecular Sequence Data
  • Organ Size
  • Phenotype
  • Sperm Count
  • Spermatids / cytology
  • Spermatogenesis / genetics*
  • Spermatozoa / abnormalities
  • Spermatozoa / cytology
  • Testis / chemistry
  • Ubiquitin-Conjugating Enzymes
  • Ubiquitins / metabolism


  • Chromatin
  • Chromosomal Proteins, Non-Histone
  • Histones
  • Ubiquitins
  • spermatid transition proteins
  • UBE2A protein, human
  • UBE2B protein, human
  • Ubiquitin-Conjugating Enzymes
  • Ligases

Associated data

  • GENBANK/X96859