Details of Award
NERC Reference : NE/J013218/1
Crossing the divide: population genomics of adaptation to salinity in a model protist.
Grant Award
- Principal Investigator:
- Dr PC Watts, University of Liverpool, Institute of Integrative Biology
- Grant held at:
- University of Liverpool, Institute of Integrative Biology
- Science Area:
- Marine
- Overall Classification:
- Marine
- ENRIs:
- Biodiversity
- Global Change
- Science Topics:
- Population Ecology
- Evolution & populations
- Microbial
- Population Genetics/Evolution
- Responses to environment
- Abstract:
- Single celled organisms (microbes) are extremely important to the health and function of global ecosystems. In particular, marine microbes assure the production of about 50% of the planetary oxygen, thus are as important as the world's rainforests, and fuel the marine food web, thereby maintaining the fisheries that are essential to mankind. It is clearly important to understand the dynamics of marine microbial populations-for example, to know the sizes and boundaries of microbial populations, the factors that determine these populations, and what environmental features affect dispersal between areas. However, becase of their small size it is almost impossible to directly track marine microbes in the natural environment and study these parameters and this aspect of their ecology and evolution remains understudied. Rather, because free-living marine microbes are assumed to have broad distributions and large population sizes, and there are a lack of obvious barriers to dispersal in most seas, there is the common assumption that marine microbial populations are widespread and also genetically diverse and homogeneous over large distances. However, this model of population structure is too simplistic: recent studies have discovered that marine microbes have complex population structures, for example, determined by the ocean currents. In many marine species, especially well-studied groups such as fish, there is evidence that the environment (e.g. salinity) has a strong effect upon what constitutes a distinct population, particularly by selecting for a specific amount and type of genetic diversity present. Such adaptation to the environment can prevent individuals from successfully moving elsewhere (i.e. to an environment that they are not suited to) and conversely prevent immigration by individuals from other areas that have different environments. Hence, understanding population adaptation to the enviroment is crucial to predict response to disturbance and future environment change. Indeed, the question of "how efficient is the environment in selecting for certain types of genetic diversity (i.e. driving population adaptation)?" has not been studied for any species of marine microbe: this represents a fundamental gap in our knowledge. We propose to collect samples of the free-living, marine microbe, Oxyrrhis marina, across the North Sea-Baltic Sea transition zone, where salinity changes along a 500 km transect from saline (~32 psu) conditions to brackish water (<10 psu). We selected this region as environmental gradients are an efficient means of studying adaptative divergence and also because salinity is one of the most important abiotic drivers for evolution in the oceans: many studies have revealed strong genetic differences between marine fish populations in the North Sea and the Baltic Sea, as well as a typical reduction in genetic diversity in Baltic Sea populations. By sequencing our samples at a large number of genes (350), we can quantify how the amount and type of genetic diversity changes along this environmental gradient. Not only do these data allow us to determine the potential for marine microbes have specific population boundaries, but they indicate how marine microbial populations, and even how specific regions of DNA, can be directly affected by the environment conditions. This will provide a better understanding of the dynamics and evolutionary mechanisms of marine microbial populations, and their capacity to withstand environment change.
- NERC Reference:
- NE/J013218/1
- Grant Stage:
- Completed
- Scheme:
- Small Grants (FEC)
- Grant Status:
- Closed
- Programme:
- Small Grants
This grant award has a total value of £33,710
FDAB - Financial Details (Award breakdown by headings)
| DI - Other Costs | Indirect - Indirect Costs | DA - Investigators | DA - Estate Costs | DI - Staff | DI - T&S | DA - Other Directly Allocated |
|---|---|---|---|---|---|---|
| £4,222 | £10,385 | £1,364 | £3,908 | £11,827 | £1,554 | £451 |
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