Laudon, M. | Search bioRxiv

bioRxiv2024

The Chlamydomonas reinhardtii CLiP2 mutant collection expands genome coverage with high-confidence disrupting alleles

Chlamydomonas reinhardtii (Chlamydomonas hereafter) is a powerful model organism for studies of photosynthesis, ciliary motility, and other cellular processes [1-4]. The CLiP library of mapped nuclear random insertion mutants [5,6] has accelerated progress for hundreds of laboratories in these fields by providing mutants in genes of interest. However, its value was limited by its modest coverage of the genome with high-confidence disruption alleles (46% of nuclear protein-coding genes with 1+ high-confidence allele in exons/introns; 12% of genes with 3+ alleles in exons/introns). Here we introduce the CLiP2 (Chlamydomonas Library Project 2) library, which greatly expands the number of available mapped high-confidence insertional mutants. The CLiP2 library includes 71,700 strains, covering 79% of nuclear protein-coding genes with 1+ high-confidence allele in exons/introns and 49% of genes with 3+ alleles in exons/introns. The mutants are available to the community via the Chlamydomonas Resource Center.

plant biology↗

bioRxiv2018

A genome-wide algal mutant library reveals a global view of genes required for eukaryotic photosynthesis

Photosynthetic organisms provide food and energy for nearly all life on Earth, yet half of their protein-coding genes remain uncharacterized1,2. Characterization of these genes could be greatly accelerated by new genetic resources for unicellular organisms that complement the use of multicellular plants by enabling higher-throughput studies. Here, we generated a genome-wide, indexed library of mapped insertion mutants for the flagship unicellular alga Chlamydomonas reinhardtii (Chlamydomonas hereafter). The 62,389 mutants in the library, covering 83% of nuclear, protein-coding genes, are available to the community. Each mutant contains unique DNA barcodes, allowing the collection to be screened as a pool. We leveraged this feature to perform a genome-wide survey of genes required for photosynthesis, which identified 303 candidate genes. Characterization of one of these genes, the conserved predicted phosphatase CPL3, showed it is important for accumulation of multiple photosynthetic protein complexes. Strikingly, 21 of the 43 highest-confidence genes are novel, opening new opportunities for advances in our understanding of this biogeochemically fundamental process. This library is the first genome-wide mapped mutant resource in any unicellular photosynthetic organism, and will accelerate the characterization of thousands of genes in algae, plants and animals.

genomics↗