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1. Chlamydomonas

   https://doi.org/10.1016/j.cub.2024.05.039  

   Tulin, Frej; Clark-Cotton, Manuella R; Onishi, Masayuki (July 2024, Current Biology)

   Tulin et al. introduce Chlamydomonas, a unicellular green alga commonly used as a microbial reference system for plants and animals. 

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2. Assembly and Repair of Photosystem II in Chlamydomonas reinhardtii

   https://doi.org/10.3390/plants13060811  

   Mehra, Himanshu S; Wang, Xiaozhuo; Russell, Brandon P; Kulkarni, Nidhi; Ferrari, Nicholas; Larson, Brent; Vinyard, David J (March 2024, Plants)

   Oxygenic photosynthetic organisms use Photosystem II (PSII) to oxidize water and reduce plastoquinone. Here, we review the mechanisms by which PSII is assembled and turned over in the model green alga Chlamydomonas reinhardtii. This species has been used to make key discoveries in PSII research due to its metabolic flexibility and amenability to genetic approaches. PSII subunits originate from both nuclear and chloroplastic gene products in Chlamydomonas. Nuclear-encoded PSII subunits are transported into the chloroplast and chloroplast-encoded PSII subunits are translated by a coordinated mechanism. Active PSII dimers are built from discrete reaction center complexes in a process facilitated by assembly factors. The phosphorylation of core subunits affects supercomplex formation and localization within the thylakoid network. Proteolysis primarily targets the D1 subunit, which when replaced, allows PSII to be reactivated and completes a repair cycle. While PSII has been extensively studied using Chlamydomonas as a model species, important questions remain about its assembly and repair which are presented here. 

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3. Cyclic electron flow (CEF) and ascorbate pathway activity provide constitutive photoprotection for the photopsychrophile, Chlamydomonas sp. UWO 241 (renamed Chlamydomonas priscuii)

   https://doi.org/10.1007/s11120-021-00877-5  

   Stahl-Rommel, Sarah; Kalra, Isha; D’Silva, Susanna; Hahn, Mark M.; Popson, Devon; Cvetkovska, Marina; Morgan-Kiss, Rachael M. (March 2022, Photosynthesis Research)
4. Systematic characterization of gene function in the photosynthetic alga Chlamydomonas reinhardtii

   https://doi.org/10.1038/s41588-022-01052-9  

   Fauser F, Vilarrasa-Blasi J (May 2022, Nature genetics)

   Most genes in photosynthetic organisms remain functionally uncharacterized. Here, using a barcoded mutant library of the model eukaryotic alga Chlamydomonas reinhardtii, we determined the phenotypes of more than 58,000 mutants under more than 121 different environmental growth conditions and chemical treatments. A total of 59% of genes are represented by at least one mutant that showed a phenotype, providing clues to the functions of thousands of genes. Mutant phenotypic profiles place uncharacterized genes into functional pathways such as DNA repair, photosynthesis, the CO2-concentrating mechanism and ciliogenesis. We illustrate the value of this resource by validating phenotypes and gene functions, including three new components of an actin cytoskeleton defense pathway. The data also inform phenotype discovery in land plants; mutants in Arabidopsis thaliana genes exhibit phenotypes similar to those we observed in their Chlamydomonas homologs. We anticipate that this resource will guide the functional characterization of genes across the tree of life. 

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5. Draft genome sequence of the Antarctic green alga Chlamydomonas sp. UWO241

   https://doi.org/https://doi.org/10.1016/j.isci.2021.102084  

   Zhang, Xi; Cvetkovska, Marina; Morgan-Kiss, Rachael; Hüner, Norman PA; Smith, David R (January 2021, iScience)

   null (Ed.)

   Antarctica is home to an assortment of psychrophilic algae, which have evolved various survival strategies for coping with their frigid environments. Here, we explore Antarctic psychrophily by examining the ∼212 Mb draft nuclear genome of the green alga Chlamydomonas sp. UWO241, which resides within the water column of a perennially ice-covered, hypersaline lake. Like certain other Antarctic algae, UWO241 encodes a large number (≥37) of ice-binding proteins, putatively originating from horizontal gene transfer. Even more striking, UWO241 harbors hundreds of highly similar duplicated genes involved in diverse cellular processes, some of which we argue are aiding its survival in the Antarctic via gene dosage. Gene and partial gene duplication appear to be an ongoing phenomenon within UWO241, one which might be mediated by retrotransposons. Ultimately, we consider how such a process could be associated with adaptation to extreme environments but explore potential non-adaptive hypotheses as well. 

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