Isolation by time during an arctic phytoplankton spring bloom

TY - JOUR

T1 - Isolation by time during an arctic phytoplankton spring bloom

AU - Tammilehto, Anna

AU - Watts, Phillip C.

AU - Lundholm, Nina

PY - 2017/3/1

Y1 - 2017/3/1

N2 - The arctic phytoplankton spring bloom, which is often diatom-dominated, is a key event that provides the high latitude communities with a fundamental flux of organic carbon. During a bloom, phytoplankton may increase its biomass by orders of magnitude within days. Yet, very little is known about phytoplankton bloom dynamics, including for example how blooming affects genetic composition and diversity of a population. Here, we quantified the genetic composition and temporal changes of the diatom Fragilariopsis cylindrus, which is one of the most important primary producers in the Arctic, during the spring bloom in western Greenland, using 13 novel microsatellite markers developed for this study. We found that genetic differentiation (quantified using sample-specific FST) decreased between time points as the bloom progressed, with the most drastic changes in FST occurring at the start of the bloom; thus the genetic structure of the bloom is characterized by isolation by time. There was little temporal variation in genetic diversity throughout the bloom (mean HE = 0.57), despite marked fluctuations in F. cylindrus cell concentrations and the temporal change in sample-specific FST. On the basis of this novel pattern of genetic differentiation, we suggest that blooming behavior may promote genetic diversity of a phytoplankton population.

AB - The arctic phytoplankton spring bloom, which is often diatom-dominated, is a key event that provides the high latitude communities with a fundamental flux of organic carbon. During a bloom, phytoplankton may increase its biomass by orders of magnitude within days. Yet, very little is known about phytoplankton bloom dynamics, including for example how blooming affects genetic composition and diversity of a population. Here, we quantified the genetic composition and temporal changes of the diatom Fragilariopsis cylindrus, which is one of the most important primary producers in the Arctic, during the spring bloom in western Greenland, using 13 novel microsatellite markers developed for this study. We found that genetic differentiation (quantified using sample-specific FST) decreased between time points as the bloom progressed, with the most drastic changes in FST occurring at the start of the bloom; thus the genetic structure of the bloom is characterized by isolation by time. There was little temporal variation in genetic diversity throughout the bloom (mean HE = 0.57), despite marked fluctuations in F. cylindrus cell concentrations and the temporal change in sample-specific FST. On the basis of this novel pattern of genetic differentiation, we suggest that blooming behavior may promote genetic diversity of a phytoplankton population.

U2 - 10.1111/jeu.12356

DO - 10.1111/jeu.12356

M3 - Journal article

C2 - 27543207

SN - 1066-5234

VL - 64

SP - 248

EP - 256

JO - Journal of Eukaryotic Microbiology

JF - Journal of Eukaryotic Microbiology

IS - 2

ER -