The genome of the polar eukaryotic microalga Coccomyxa subellipsoidea reveals traits of cold adaptation

Year: 2012

Type: article

Abstract: BACKGROUND: Little is known about the mechanisms of adaptation of life to the extreme environmental conditions encountered in polar regions. Here we present the genome sequence of a unicellular green alga from the division chlorophyta, Coccomyxa subellipsoidea C-169, which we will hereafter refer to as C-169. This is the first eukaryotic microorganism from a polar environment to have its genome sequenced. RESULTS: The 48.8 Mb genome contained in 20 chromosomes exhibits significant synteny conservation with the chromosomes of its relatives Chlorella variabilis and Chlamydomonas reinhardtii. The order of the genes is highly reshuffled within synteny blocks, suggesting that intra-chromosomal rearrangements were more prevalent than inter-chromosomal rearrangements. Remarkably, Zepp retrotransposons occur in clusters of nested elements with strictly one cluster per chromosome probably residing at the centromere. Several protein families overrepresented in C. subellipsoidae include proteins involved in lipid metabolism, transporters, cellulose synthases and short alcohol dehydrogenases. Conversely, C-169 lacks proteins that exist in all other sequenced chlorophytes, including components of the glycosyl phosphatidyl inositol anchoring system, pyruvate phosphate dikinase and the photosystem 1 reaction center subunit N (PsaN). CONCLUSIONS: We suggest that some of these gene losses and gains could have contributed to adaptation to low temperatures. Comparison of these genomic features with the adaptive strategies of psychrophilic microbes suggests that prokaryotes and eukaryotes followed comparable evolutionary routes to adapt to cold environments.

Source: Genome biology

DOI: 10.1186/gb-2012-13-5-r39

Institutions: Centre National de la Recherche Scientifique, Aix-Marseille Université, Institut de Microbiologie de la Méditerranée, Laboratoire Information Génomique et Structurale, University of Nebraska–Lincoln, Joint Genome Institute, University of Rostock, Hiroshima University, Georgia Institute of Technology, The Wallace H. Coulter Department of Biomedical Engineering

Language: English

Topic: Polar Research and Ecology

Subfield: Ecology

Field: Environmental Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $5,490

Funders: National Science Foundation, U.S. Department of Energy, Joint Genome Institute, National Institutes of Health, Office of Science, Japan Society for the Promotion of Science, National Human Genome Research Institute, National Center for Research Resources, Office of Experimental Program to Stimulate Competitive Research

OpenAlex ID: W2120807642