The NOMEGA gene required for female gametophyte development encodes the putative APC6/CDC16 component of the Anaphase Promoting Complex in Arabidopsis

Plant J. 2003 Dec;36(6):853-66. doi: 10.1046/j.1365-313x.2003.01925.x.


Development of the female gametophyte involves several rounds of nuclear divisions during which nuclei are rearranged and finally cellularized to form a mature seven-celled embryo sac. During these nuclear divisions, key proteins involved in the cell cycle need to be degraded quickly in order to facilitate both the metaphase-anaphase transition stage and late anaphase. Here, we report the characterization of an Arabidopsis mutant nomega, which results in arrest of the embryo sac development at the two-nucleate stage. The NOMEGA gene product shows high homology to the APC6/cell division cycle (CDC)16 subunit of the Anaphase Promoting Complex/Cyclosome (APC/C). The phenotype of the nomega mutant is quite different from that of the hobbit mutant, which had suggested a role for the plant APC/C in auxin signalling. We show that nomega mutant embryo sacs are unable to degrade Cyclin B, an important APC/C substrate, providing further evidence of a role for the NOMEGA gene product and the plant APC/C in cell cycle progression during gametophyte development.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Anaphase-Promoting Complex-Cyclosome
  • Animals
  • Apc6 Subunit, Anaphase-Promoting Complex-Cyclosome
  • Arabidopsis / enzymology
  • Arabidopsis / genetics*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Base Sequence
  • Germination / genetics*
  • Humans
  • Molecular Sequence Data
  • Mutagenesis
  • Phenotype
  • Protein Subunits / genetics
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Sequence Homology, Nucleic Acid
  • Ubiquitin-Protein Ligase Complexes / genetics
  • Ubiquitin-Protein Ligase Complexes / metabolism*


  • Anaphase-promoting complex subunit 6 protein, Arabidopsis
  • Apc6 Subunit, Anaphase-Promoting Complex-Cyclosome
  • Arabidopsis Proteins
  • Protein Subunits
  • Ubiquitin-Protein Ligase Complexes
  • Anaphase-Promoting Complex-Cyclosome