Professor Sir David Baulcombe at Cornell and BTI

Here’s a puzzle: if you catch a virus before you’ve had children, and it doesn’t change your DNA, could your grandchildren be genetically different as a result?

While conventional wisdom would say that’s impossible, Professor Sir David Baulcombe, from the Department of Plant Sciences at the University of Cambridge, is in the business of asking questions that push the boundaries of possibility. At the invitation of BTI’s Postgraduate Society and Cornell’s School of Integrative Plant Science, he gave a lecture to a standing-room-only crowd on October 21, 2014.

Dr. Baulcombe’s current work builds on his groundbreaking discovery of small interfering RNA, siRNA for short. When a plant cell recognizes invasive genetic material, siRNA specific to the foreign genes pinpoints those invader genes for silencing with deadly accuracy. This is a good way for cells to ward off viruses and it provides a great tool to researchers, who now use this system to selectively silence genes of interest in the genome of the organism itself.

Not content to just use this new tool, Dr. Baulcombe’s team continues to delve into the heart of the matter: from where in the genome do siRNAs arise? What proteins do they partner with to do their work? Dr. Baulcombe’s group has noted that genomic signatures of the origins of siRNA vary distinctively even in related plant species, and they’ve begun to watch what happens to those parts of the genome in hybrids from edible species of tomato and their wild relatives. Surprisingly, hybrid plants produce much higher levels of siRNAs than their parents do, pointing towards a role for siRNAs in the question of why hybrids can be more vigorous than their parents.

Speaking of siRNA and inheritance through the generations, are you still wondering if catching a virus can really affect your grandchildren? Well, in plants it can! Plants expressing a gene for the green fluorescent protein (GFP) have leaves that glow green and, if infected with a virus that stimulates the production of siRNA to silence GFP, the plant will stop glowing, as you might expect. Remarkably however, Dr. Baulcombe’s group found that though they inherit the gene for GFP and have no contact with the virus, that plant’s offspring will also not glow, nor will the offspring of its offspring.

Dr. Baulcombe has already changed the face of molecular biology and the impact of his work is sure to be felt for generations to come. To follow the progress of Dr. Baulcombe’s team, please visit their website at http://www.plantsci.cam.ac.uk/research/davidbaulcombe .

View the video of Sir David’s talk at Cornell, entitled ‘When genomes meet: RNA silencing and the phenotypes of hybrid plants’: