A forward genetic approach in Chlamydomonas reinhardtii as a strategy for exploring starch catabolism

PLoS One. 2013 Sep 3;8(9):e74763. doi: 10.1371/journal.pone.0074763. eCollection 2013.


A screen was recently developed to study the mobilization of starch in the unicellular green alga Chlamydomonas reinhardtii. This screen relies on starch synthesis accumulation during nitrogen starvation followed by the supply of nitrogen and the switch to darkness. Hence multiple regulatory networks including those of nutrient starvation, cell cycle control and light to dark transitions are likely to impact the recovery of mutant candidates. In this paper we monitor the specificity of this mutant screen by characterizing the nature of the genes disrupted in the selected mutants. We show that one third of the mutants consisted of strains mutated in genes previously reported to be of paramount importance in starch catabolism such as those encoding β-amylases, the maltose export protein, and branching enzyme I. The other mutants were defective for previously uncharacterized functions some of which are likely to define novel proteins affecting starch mobilization in green algae.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Chlamydomonas reinhardtii / genetics*
  • Chlamydomonas reinhardtii / metabolism
  • DNA Primers
  • Mutation
  • Polymerase Chain Reaction
  • Starch / metabolism*


  • DNA Primers
  • Starch

Grant support

This work was supported by the Centre National de la Recherche Scientifique (CNRS), the Université des Sciences et Technologies de Lille (USTL) and the Institut Français des Matériaux Agro-Sourcés (IFMAS). pHD grants from the Ministère de la recherche et de l'enseignement supérieur (HT) and the Région Nord Pas de Calais and the Université des Sciences et technologies de Lille (JF). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.