Back to Search
Start Over
Evolutionary genomics of the cold-adapted diatom Fragilariopsis cylindrus.
- Source :
-
Nature [Nature] 2017 Jan 26; Vol. 541 (7638), pp. 536-540. Date of Electronic Publication: 2017 Jan 16. - Publication Year :
- 2017
-
Abstract
- The Southern Ocean houses a diverse and productive community of organisms. Unicellular eukaryotic diatoms are the main primary producers in this environment, where photosynthesis is limited by low concentrations of dissolved iron and large seasonal fluctuations in light, temperature and the extent of sea ice. How diatoms have adapted to this extreme environment is largely unknown. Here we present insights into the genome evolution of a cold-adapted diatom from the Southern Ocean, Fragilariopsis cylindrus, based on a comparison with temperate diatoms. We find that approximately 24.7 per cent of the diploid F. cylindrus genome consists of genetic loci with alleles that are highly divergent (15.1 megabases of the total genome size of 61.1 megabases). These divergent alleles were differentially expressed across environmental conditions, including darkness, low iron, freezing, elevated temperature and increased CO <subscript>2</subscript> . Alleles with the largest ratio of non-synonymous to synonymous nucleotide substitutions also show the most pronounced condition-dependent expression, suggesting a correlation between diversifying selection and allelic differentiation. Divergent alleles may be involved in adaptation to environmental fluctuations in the Southern Ocean.
- Subjects :
- Alleles
Carbon Dioxide metabolism
Darkness
Diatoms metabolism
Freezing
Gene Expression Profiling
Genetic Drift
Ice Cover
Iron metabolism
Mutation Rate
Oceans and Seas
Phylogeny
Recombination, Genetic
Transcriptome genetics
Acclimatization genetics
Cold Temperature
Diatoms genetics
Evolution, Molecular
Genome genetics
Genomics
Subjects
Details
- Language :
- English
- ISSN :
- 1476-4687
- Volume :
- 541
- Issue :
- 7638
- Database :
- MEDLINE
- Journal :
- Nature
- Publication Type :
- Academic Journal
- Accession number :
- 28092920
- Full Text :
- https://doi.org/10.1038/nature20803