HL: You're listening to a podcast from the Medical Research Council with Hazel Lambert. The genome of a tiny red beetle, the type you might find nestled inside the kitchen flower jar has been published in Nature. Medical Research Council scientist Professor David Sattelle and Dr Andrew Jones who work in the MRC functional genetics unit are part of an international consortium of scientists who together identified every gene. Professor Sattelle, first of all why is sequencing and other animal genomes so important?
DS: Well the publication of any animal genome, which is its entire DNA sequence, is always exciting. It means that another animal joins that small group for which the complete DNA blueprint is known. And this group now includes ourselves and several other vertebrates such as the chimp and the mouse as well as invertebrates such as the fruit fly and the remarkable nematode worm, in fact the first animal genome to be sequenced was that of the worm. So work on simple invertebrate animals has paved the way not only for modern genetics but also for the new exciting field of genomics and this latest invertebrate genome to be sequenced is that of the red flour beetle – Tribolium castaneum and it's familiar to most of us as the unwelcome little visit to the kitchen flour jar. HL: Why did you choose to sequence the genome of this red flour beetle?
DS: Well this particular beetle has been studied for many years by biologists interested in how organisms develop and fascinatingly important genes controlling development are shared by humans and even the simplest of animals. So this new genome is important for the benefits that it will bring to developmental biology. Beetles are arguably the most successful group of animals on the planet; we can recognise more of them than of any other animal group. Charles Darwin was particularly fascinated by them. There are several pages in fact in his classic work, The Descent of Man, which are devoted to beetles. So studies on beetles helped inform Darwin's thinking and his theory of evolution by natural selection is the greatest idea in biology and is at the very heart of all modern genomics research. HL: So Darwin learnt about his theories of evolution looking at beetles, but what have you learnt about this particular beetle after sequencing its genome that you didn't know before? DS: Well many things. The genome reflects how an organism lives its life. We see in this beetle an expansion of receptor molecules and hormones associated with life in an extremely dry environment.
HL: Earlier you mentioned the nematode worm and the fruit fly, and they're both commonly used in genetic research to learn more about how genes influence the development of disease in humans, do you think that the red flour beetle could also be used as a model of the human genome to further study disease in this way? DS: Well this organism's a good model for the study of development and there are many human developmental disorders that are not yet fully understood. As is the case for the worm and the fly, tribolium is well suited to gene knock down studies and this approach helps us to understand gene function and can also be used to mimic aspects of human diseases in invertebrate model organisms. There are a number of diseases that are developmentally regulated, so the contributions it can make to understanding animal development I think will be extremely important. But also being another genome it gives us yet another set of DNA to compare with those that we know already. So I think it has intrinsic interest from that point of view as well as the contributions it can make to understanding disease.
HL: Like many genetic research projects, this one was an international collaboration. Could you describe to me how these collaborations actually work?
DS: Well the internet has proved invaluable for helping to exchange large amounts of DNA sequence and we keep in touch with conference telephone calls on a regular basis.
HL: So no beetles in the post?
DS: We don't need to do that, no. [Laughs] HL: [Laughs] Ok and finally if you divided up the project, which part of the beetle genome did your lab work on? DS: My colleagues and I have done our own beetling around in this and other genomes to learn more about a family of important molecular switch proteins. These are neurotransmitter gater iron channels, they're involved in signally between nerve cells and they're present in the simplest nervous systems as well as our own. So comparisons between the gene family members in different organisms can offer new insights into how these molecular switches work. Subtle differences in their DNA sequence and function can even help us pin down the sites of action of important human drugs being developed for major diseases such as Alzheimer's and other neurodegenerative diseases. So overall it's capturing value from genome sequence for human health benefits that is at the core of what we do. HL: For more news about MRC funded research and discoveries visit the Medical Research Council website at mrc.ac.uk.
HL: Hazel Lambert DS: Professor David Sattelle
