The persistence and spread of novel genes

A transgenic, that is genetically modified, oilseed rape (Brassica napus) provides the model system with which we have investigated the dynamics of novel genes in local populations. A stochastic, spatially explicit individual based model (IBM) was developed to simulate the dynamics of the transgene introduced into a non-transgenic population. The model combines life-history and management processes with environmental drivers to examine the effect of these on the spread and persistence of the transgene and the conferred trait.

The model has been used to explore a number of features of this system:

Gene flow patch diagramSpread and persistence in patchy populations - Plant populations, including arable weeds, typically exhibit spatial heterogeneity, that is patchiness, in their distribution. Together with the localised nature of plant to plant interactions this has the potential to affect the dynamics of a population and the spread and persistence of the genes they posses. Model simulations have shown that small scale spatial heterogeneity in the distribution of transgenic plants combined with localised pollen dispersal reduces mixing between populations and acts to limit the spread of the gene through the population.

The impact of climate change - The inclusion of temperature and soil moisture as drivers of important life-cycle processes allows the impact of climate change on population and gene dynamics to be considered. For example, simulations show that elevated temperature and soil moisture could lead to a reduction in seedbank densities as the timing of cultivation after harvest becomes less critical making agronomic control easier.

Economic impact of crop impurities - By linking crop prices to simulations of GM impurities in harvested seed we have been able to explore the costs experienced by a farmer when they move a field out of GM oilseed rape production and the financial risk associated with a range of exit strategies.

Follow this link for more information on research into gene flow and persistence at SCRI.

Papers and reports

Begg, G.S., Elliott, M.J, Iannetta, P.P.M., Young, M.W, Squire, G.R. 2007. Localised heterogeneity, gene flow and the persistence of transgenes from genetically modified oilseed rape. Third international conference on co-existence between genetically modified (GM) and non-GM based agricultural supply chains" Seville Spain 20-21 November 2007. Book of Abstracts GMCC-07, 101.

Begg, G.S., Elliott, M.J., Squire, G. R., Copeland, J. 2006. Final report of the DEFRA project: Prediction, sampling and management of GM impurities in fields and harvested yields of oilseed rape, VS0126.

Begg, G.S., Young, M.W., Hawes, C., Squire, G.R. 2004. Persistence and potential impact of GMHT impurity in oilseed rape. Aspects of Applied Biology 74, 211-217.

Begg, G.S., Hawes, C., Marshall, B., D'Hertefeldt, T., Ramsay, G., Young, M.W., Squire, G.R., Wright, G.M. 2002 Dispersal and persistence of feral oilseed rape - mechanisms and consequences. ESF Working Group Meeting: Estimating and Managing Geneflow and Dispersal in GM Crops, Lille, France, 2-3 July 2002.