Plant epigenetics: do plants have a memory? - Martin Howard

How do organisms remember things that are not in their DNA sequence? Epigenetics, once heretical in biology, are now a mainstream topic of research, vital for understanding cell differentiation and disease. Enormous progress has been made in recent years in elucidating the basis of epigenetic regulation. Our ability to interrogate epigenetic dynamics at a genomic scale, often using sophisticated bioinformatic tools, has been central to this step change. Yet many questions concerning epigenetic memory remain unanswered. Here, Martin Howard presents an alternative approach based on dissecting regulatory control at an individual gene through a fusion of mathematical modelling and cell experiments. This approach has provided novel insights and has allowed us to move beyond the correlative analyses frequently provided by epigenomic approaches. Martin describes how a transient environmental signal (exposure to cold temperatures) can establish a prolonged response in plants. The response continues even after after the signal itself is gone, implying that plants can "remember" they were exposed to cold. Epigenetic regulation explains how this long-term information storage is achieved. 0:00 Introduction to epigenetic inheritance 3:07 The need for modelling 10:17 Applying modelling to epigenetics 11:29 What questions do we want to answer? 13:49 What system can we use to address these questions? 21:39 Epigenetic memory: how is it stored, in trans or in cis? 38:19 Testing the models 48:44 Consequences of integrating cis and trans gene regulation 49:59 Mechanistic dissection of epigenetics Speaker profile: Martin Howard is a Professor at the John Innes Centre in Norwich: "From an early age, I always knew that I wanted to be a scientist. There seemed to be nothing else that could match the excitement of discovering something that no one else knew: 35 years later, I can only agree! At school I studied double maths and physics, before going to Oxford to read physics, where I specialised in the most theoretical areas. I then pursued a PhD and a couple of postdocs in theoretical physics in Copenhagen and Vancouver. However, I was beginning to grow dissatisfied with my research, which although interesting and intellectually demanding, was completely lacking in contact with experiments. I therefore resolved to switch to something more interesting, where I could feel that I was making a difference. I was lucky to find an extremely appropriate first problem (cell division positioning in E. coli), after which I secured a Royal Society University Research Fellowship at Imperial in 2002. Subsequently, I have pioneered a style of research involving long-term close collaboration with experimentalists to accelerate the discovery of fundamental biological mechanism. In 2007, I moved to take up a professorship at the John Innes Centre, where my research interests have moved on to encompass epigenetics, a topic where investigating plants turns out to have unique advantages over other organisms." Filmed at the Gatsby Plant Science Summer School, 2018. #plantscience #epigenetics #genetics