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| Titel |
Genotyping an Emiliania huxleyi (prymnesiophyceae) bloom event in the North Sea reveals evidence of asexual reproduction |
| VerfasserIn |
S. A. Krueger-Hadfield, C. Balestreri, J. Schroeder, A. Highfield, P. Helaouët, J. Allum, R. Moate, K. T. Lohbeck, P. I. Miller, U. Riebesell, T. B. H. Reusch, R. E. M. Rickaby, J. Young, G. Hallegraeff, C. Brownlee, D. C. Schroeder |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 11, no. 18 ; Nr. 11, no. 18 (2014-09-29), S.5215-5234 |
| Datensatznummer |
250117613
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| Publikation (Nr.) |
 copernicus.org/bg-11-5215-2014.pdf |
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| Zusammenfassung |
| Due to the unprecedented rate at which our climate is changing, the ultimate
consequence for many species is likely to be either extinction or migration
to an alternate habitat. Certain species might, however, evolve at a rate
that could make them resilient to the effects of a rapidly changing
environment. This scenario is most likely to apply to species that have large
population sizes and rapid generation times, such that the genetic variation
required for adaptive evolution can be readily supplied. Emiliania
huxleyi (Lohm.) Hay and Mohler (Prymnesiophyceae) is likely to be such a
species, as it is the most conspicuous extant calcareous phytoplankton species
in our oceans with growth rates of 1 day−1. Here we report on a
validated set of microsatellites, in conjunction with the coccolithophore
morphology motif genetic marker, to genotype 93 clonal isolates collected
from across the world. Of these, 52 came from a single bloom event in the
North Sea collected on the D366 United Kingdom Ocean Acidification cruise in
June–July 2011. There were 26 multilocus genotypes (MLGs) encountered only
once in the North Sea bloom and 8 MLGs encountered twice or up to six times.
Each of these repeated MLGs exhibited Psex values of less than
0.05, indicating each repeated MLG was the product of asexual reproduction and
not separate meiotic events. In addition, we show that the two most
polymorphic microsatellite loci, EHMS37 and P01E05, are reporting on regions
likely undergoing rapid genetic drift during asexual reproduction. Despite
the small sample size, there were many more repeated genotypes than
previously reported for other bloom-forming phytoplankton species, including
a previously genotyped E. huxleyi bloom event. This study
challenges the current assumption that sexual reproduction predominates
during bloom events. Whilst genetic diversity is high amongst extant
populations of E. huxleyi, the root cause for this diversity and
ultimate fate of these populations still requires further examination.
Nonetheless, we show that certain CMM genotypes are found everywhere, while
others appear to have a regional bias. |
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