Associate Professor Peter Dearden is a scientist from Otago University in Dunedin, New Zealand. He is a principal investigator of Gravida: National Centre for Growth & Development, and is the Director of Genetics Otago. His research areas of interest include developmental biology (how a being develops from an egg to an adult), epigenetics (of which you'll see more on here later) and insects - specifically bees, and trying to save them. Peter's lab website is here and he has a blog here and is on twitter. You might even have seen Peter in the news or heard him on the radio. Today Peter is going to talk to us about why insects matter.
Insects are important. They are more than just pesky things that bite or sting, or eat things you want to eat. They matter. Around 1/3 of the food we eat requires pollination, most of it from insects. Insects destroy our food, both on the plant and in storage. The most dangerous animal in the world is an insect; mosquitos that carry malaria.
Insects are important, not just good and certainly not just bad. In science, particularly genetics, insects are great. Much of what we know about animal genes and what they do comes from studies of insects. The Fruit Fly, Drosophila melanogaster, has been used for over 100 years in genetics experiments, and has provided information on a huge range of biological issues. Drosophila showed us how chromosome are organised, how they recombine, how they respond to chemical mutagens and radiation; incidentally sparking the fist scientific protests about nuclear weapons. Flies showed us how embryos are built, how genes and cells coordinate to make the body, limbs, brains etc of an animal. Genomics was invented in flies; they were the second animal genome to be sequenced, and one of only two that are fully sequenced. Flies have been the animal model of choice for geneticists since 1910.
So that’s cool, but how does this apply to us? There are two ways to answer that question. Firstly, the basic knowledge of how one animal works, provides a model for other animals. Sure the details will differ, but learning how something works in one system, tells you how it might work in another. The other way to answer this question is more interesting.
While we are very different from flies, we share a lot in common. Our lineage split from the last common ancestor of flies around 750 million years ago. While that is a long time, the last common ancestor of flies and ourselves was not that dissimilar to us. It had a brain, it had a nervous system, it probably had limbs, it had eyes, and most importantly it had a genome containing lots of genes.
Evolution is a conservative process; it doesn’t change things radically, it tinkers over time with the components it has and makes something new with them. Because of this, and because we evolved from a common ancestor, many of the genes in our genome are shared with flies. Indeed, when the draft human genome was published it was suggested that we share 75% of our genes with flies. When you look at the genes that are involved in making an embryo or involved in cells talking to each other or involved in human disease, this figure is higher. We share lots of our biology with flies. In my own field, developmental genetics, the genes and process that make an embryo in flies have all been found in humans. These genes and processes may act at different times and places, but they are the same ones. Studying flies isn’t all about flies, it is often studying genes and processes we know also work in humans.
Combine this genetic similarity to humans to the tools and experiments we can do in flies, and you have a very powerful combination. Fruit flies are heroes of human genetics; they are an effective, cheap and are an insightful way of understanding biology.
Don’t get me wrong, fruit flies don’t tell us everything. Their biology is missing some things, and they are not vertebrates. We need other models for other things; for example I study plasticity in bees because fruit flies don’t do much of it. But bees are equally useful models to understand humans. Other people study zebrafish or mice to look at how what we know from other animals might apply to vertebrates and humans.
Flies provide a start, and fantastic one, that allows us to begin to unravel the biology of animals and ultimately ourselves.