Transgene expression and fitness of hybrids between GM oilseed rape and Brassica rapa

Free access article

Issue		Environ. Biosafety Res. Volume 4, Number 1, January-March 2005


Page(s)		3 - 12
DOI		10.1051/ebr:2005010

Environ. Biosafety Res. 4 (2005) 3-12
DOI: 10.1051/ebr:2005010

Transgene expression and fitness of hybrids between GM oilseed rape and Brassica rapa

Henriette Ammitzbøll, Teis Nørgaard Mikkelsen and Rikke Bagger Jørgensen

Biosystems Department, Risø National Laboratory, P.O. Box 49, 4000 Roskilde, Denmark

(Received March 4, 2005; accepted July 4, 2005)

Abstract
Oilseed rape (Brassica napus) is sexually compatible with its wild and weedy relative B. rapa, and introgression of genes from B. napus has been found to occur over a few generations. We simulated the early stages of transgene escape by producing F₁ hybrids and the first backcross generation between two lines of transgenic B. napus and two populations of weedy B. rapa. Transgene expression and the fitness of the hybrids were examined under different environmental conditions. Expression of the transgenes was analyzed at the mRNA level by quantitative PCR and found to be stable in the hybrids, regardless of the genetic background and the environment, and equal to the level of transcription in the parental B. napus lines. Vigor of the hybrids was measured as the photosynthetic capability; pollen viability and seed set per silique. Photosynthetic capability of first generation hybrids was found to be at the same level, or higher, than that of the parental species, whereas the reproductive fitness was significantly lower. The first backcross generation had a significantly lower photosynthetic capability and reproductive fitness compared to the parental species. This is the first study that examines transgene expression at the mRNA level in transgenic hybrids of B. napus of different genetic background exposed to different environmental conditions. The data presented clarify important details of the overall risk assessment of growing transgenic oilseed rape.

Key words: real time PCR / Fv/Fm / F₀ / heterosis / biosafety

Corresponding author: Rikke Bagger Jørgensen rikke.bagger.jorgensen@risoe.dk

© ISBR, EDP Sciences 2005

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.