Publication Date:
2019-03-08
Description:
Coccolithophores have influenced the global climate for over 200
million years1. These marine phytoplankton can account for 20 per
cent of total carbon fixation in some systems2. They form blooms
that can occupy hundreds of thousands of square kilometres and
are distinguished by their elegantly sculpted calcium carbonate exoskeletons
(coccoliths), rendering themvisible fromspace3.Although
coccolithophores export carbon in the form of organic matter and
calcite to the sea floor, they also release CO2 in the calcification
process. Hence, they have a complex influence on the carbon cycle,
driving either CO2 production or uptake, sequestration and export
to the deep ocean4. Here we report the first haptophyte reference
genome, from the coccolithophore Emiliania huxleyi strain
CCMP1516, and sequences from 13 additional isolates. Our analyses
reveal a pan genome (core genes plus genes distributed variably
between strains) probably supported by an atypical complement
of repetitive sequence in the genome. Comparisons across strains
demonstrate thatE. huxleyi, which has long been considered a single
species, harbours extensive genome variability reflected in different
metabolic repertoires. Genome variability within this species
complex seems to underpin its capacity both to thrive in habitats
ranging from the equator to the subarctic and to form large-scale
episodic blooms under a wide variety of environmental conditions.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
