TAC-1, a regulator of microtubule length in the C. elegans embryo

Curr Biol. 2003 Sep 2;13(17):1499-505. doi: 10.1016/s0960-9822(03)00577-3.


Regulation of microtubule growth is critical for many cellular processes, including meiosis, mitosis, and nuclear migration. We carried out a genome-wide RNAi screen in Caenorhabditis elegans to identify genes required for pronuclear migration, one of the first events in embryogenesis requiring microtubules. Among these, we identified and characterized tac-1 a new member of the TACC (Transforming Acidic Coiled-Coil) family [1]. tac-1(RNAi) embryos exhibit very short microtubules nucleated from the centrosomes as well as short spindles. TAC-1 is initially enriched at the meiotic spindle poles and is later recruited to the sperm centrosome. TAC-1 localization at the centrosomes is regulated during the cell cycle, with high levels during mitosis and a reduction during interphase, and is dependent on aurora kinase 1 (AIR-1), a protein involved in centrosome maturation. tac-1(RNAi) embryos resemble mutants of zyg-9, which encodes a previously characterized centrosomal protein of the XMAP215 family and was also found in our screen. We show that TAC-1 and ZYG-9 are dependent on one another for their localization at the centrosome, and this dependence suggests that they may function together as a complex. We conclude that TAC-1 is a major regulator of microtubule length in the C. elegans embryo.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / metabolism
  • Cell Cycle / physiology*
  • Centrosome / metabolism
  • Gene Expression Profiling
  • Genomic Library
  • Male
  • Microtubule-Associated Proteins / metabolism*
  • Microtubule-Organizing Center / metabolism
  • Microtubules / metabolism*
  • Nuclear Proteins*
  • RNA Interference
  • Spermatozoa / cytology
  • Trans-Activators / metabolism


  • Caenorhabditis elegans Proteins
  • MHC class II transactivator protein
  • Microtubule-Associated Proteins
  • Nuclear Proteins
  • Trans-Activators
  • ZYG-9 protein, C elegans