Chlamydomonas genomics: Photosynthesis and acclimation

Carnegie Institution Of Washington, Washington DC

Investigators

Abstract

This award provides continuing support for the development and application of genomic resources for the study of fundamental biological processes in Chlamydomonas, an important model organism. This project will enhance the use of Chlamydomonas for elucidating the regulation of the photosynthetic apparatus with respect to changing environmental conditions. The investigators have the following five goals: (1) Implement a Generic Model Organism Database (GMOD) for Chlamydomonas that will display the genome and its features, including coding regions, ESTs, cDNAs, splice sites, BAC positions, molecular markers and sites of insertion elements in mutant strains. (2) Create a Phase II microarray representing 8,500-10,000 unique genes and supplement the array with an oligonucleotide-based array that will include genes that are defined by whole genome sequencing and that are not included on the Phase II array. Arrays will be used to catalog mechanisms of acclimation to environmental stress, using both wild-type and mutant strains whose biological phenotypes have already been determined; an emphasis will be placed on photosynthetic function. (3) Build an insertional mutant collection saturated for nuclear genes whose products are linked to photosynthetic function. Insertion strains will be challenged with a battery of screens, and the insertion sites of 5,000 strains affected in photosynthetic function will be sequenced and made available to the community. (4) Create high-throughput mapping tools to facilitate gene isolation from mutants that are not tagged by insertions. These will primarily be suppressors of other mutations, or mutations in genes for which a null lesion would be lethal. The mapping will be based on simple sequence repeats, automated and made more rapid by the use of bulked segregant analysis. A mapping service will also be offered to the community. (5) Develop vectors to facilitate RNA interference-mediated reverse genetics. Chlamydomonas reinhardtii, a unicellular haploid green alga, is an important model system for elucidating basic biological processes, especially in plants. The further development of sophisticated genome-wide methodologies for studies of Chlamydomonas will greatly augment its usefulness to the scientific community. This project will also produce extensive data on photosynthesis and acclimation, adding to our knowledge of how photosynthetic organisms sense, respond to, and survive in a rapidly changing environment. It will also enhance Chlamydomonas's usefulness as a 'training' organism in laboratories throughout the world, and provide a new and exciting entry point into research careers for young scientists.