James and the Giant Corn Rotating Header Image

August 2nd, 2010:

Variation in Gene Expression and Hybrid Vigor

Don’t you just love creative commons licensed images?

Cover image from Rosas et al 2010 PLoS Biology. (Click the image to view it in its original context)

In this case the story behind the image in a paper on hybrid vigor, another subject close to the heart of any biologist who has ever worked with corn, although this group worked with snapdragon, a species that is used as a model system for flower morphology. Snapdragon flowers are interesting genetically because they are only symmetric along one axis. The genes behind this trait have been studied for quite some time and have names like Cycloidea, Radialis and Divaricata. <– Snapdragon folks generally come up with classier sounding names for their genes than the communities for many other model species.

Snapdragon flowers can be symmetrically folder over one axis, but not the other. (Modified from the image above).

The authors of this paper found that the expression* of a number of these genes varied between different species within the snapdragon genus (Antirrhinum). So far so good, but the really exciting bit of this paper is that the authors use the version of these genes from different species (with significantly different levels of expression) to show that while the changes in expression observed between different species don’t make much of a difference to the final shape of snapdragon flowers, being stuck with a low expression version of a gene to begin with means a snapdragon plant has a much more altered shape when one of the copies of that gene is completely broken. (more…)