2020 Hutton Medal: Understanding the biology of 'mother’s curse', sex change in fish and the tuatara genome
Distinguished Professor Neil Gemmell has been been awarded the Hutton Medal by Royal Society Te Apārangi for his research that is fundamentally changing our understanding of animal ecology and evolution and is driving the development of new approaches for conservation and management of the world’s rarest species.
An evolutionary and reproductive biologist, Neil’s research is multidisciplinary, blending ecology, population biology, conservation and evolutionary theory with cutting-edge genomic technology and analysis.
Neil has consistently devised, adapted, and applied the latest molecular genetic and analytical approaches to address questions relating to the ecology and evolution of a variety of species, including the platypus, New Zealand native and Amazonian frogs, birds, sea mammals, marine invertebrates and most recently, the tuatara. His work has influenced species conservation and management plans of some of the world’s rarest species.
Arguably, Neil’s most influential research has been developing the “mother’s curse” hypothesis and investigating the potential impacts of this phenomenon. Neil has shown how deleterious mitochondrial DNA mutations that affect only males, such as those that impair sperm function, will not be selected against in a population, because mitochondria are passed on solely by the mother. Thus, these mutations can reach high frequencies as long as the fitness of the females with these mutations is maintained. This phenomenon has many implications, for example in helping to explain the commonly observed sex bias in longevity. But, on a more practical level, he has investigated how this can be applied in a novel biocontrol context for the management of a wide variety of pest species, an approach referred to as the “Trojan Female Technique”.
His research team has also been making advances on understanding of one of the most startling transformations in the natural world – the complete reversal of sex that occurs in about 500 species of fish. For example, all bluehead wrasse begin life as females, but can later change to males in a process that takes just 10–21 days from start to finish. The research has revealed that sex change involves a complete genetic rewiring of the gonad: specific genes are turned off and on in the brain and gonad so that sex change can occur.
Neil was lead author on sequencing the tuatara genome, published in Nature in August 2020. This genome is 67 per cent larger than the human genome and possesses a genomic architecture unlike anything previously reported. The research confirms how ancient the tuatara lineage is, showing this species shared a common ancestor with its closet reptilian kin, the snakes and lizards, a staggering 250 million years ago. One area of particular interest is to understand how tuatara, which can live to more than 100 years of age, achieve such longevity. Examination of some of the genes implicated in protecting the body from the ravages of age found that tuatara have more of these genes than any other vertebrate species thus far examined. How this new genetic knowledge can help conserve this living taonga is another important aspect of the project.
Professor Gemmell holds one of the seven Sesquicentennial Distinguished Chairs (Poutoko Taiea) and is the AgResearch Chair of Reproduction and Genomics at the University of Otago. An exceptional science leader, he enables multiple national science infrastructure projects and supports many students. His contributions have been recognised by the MJD White Medal for Excellence in Genetic Research from the Genetics Society of Australasia (2018), University of Otago Research Group Award (2018), a Fulbright Senior Fellowship 2018–19, the New Zealand Society for Biochemistry and Molecular Biology Award for Research Excellence (2019), The Society for Reproductive Biology Founders Lecture and Medal (2020) and his election as a Fellow of the Linnean Society of London (2017).
On receiving the Hutton Medal, Neil said:
“I am deeply humbled to receive the 2020 Hutton Medal from the Royal Society Te Apārangi. I thank those that supported my nomination and ultimately selected me for this honour. I also thank my family and friends for their unwavering support over my career to date, and the students, staff, collaborators, colleagues and mentors that I have worked with in New Zealand and across the globe and I thank the institutions, notably the University of Otago, and numerous funding bodies, that have supported both me and my work over the course of my career.
“In receiving this award, I am mindful of the many accomplishments of the previous winners of this award. Across our country, the collective efforts of many hundreds of researchers working in schools, universities, CRIs, iwi, government and regional bodies, has steadily increased our understanding of the flora, fauna and geology of one of the world’s great treasures – Aotearoa New Zealand. I am proud to be part of that community and to have provided some new insight into our remarkable fauna.
“But there remains much to do. While our understanding of our nation’s biota continues to grow, we must find new solutions to balance the use and protection of our natural systems and find better ways to protect the species that depend on these. In particular it is vital that we start to actively manage the impacts that climate change and other factors that, left unchecked, will result in a rapid deterioration in our natural systems.
“Genetics, my particular area of expertise, has already emerged as an important part of the toolkit for documenting our natural systems, documenting ecological change, and for ameliorating the most pressing effects of the biodiversity crisis. However, as the technology increases in power and portability, while costs decrease, we will see genetics move from the lab to the seashore, riverside, roadside, and kitchen table. Harnessing this revolution in genomic capability with citizen science initiatives will democratise the process of scientific discovery, building a more informed society and future through which we understand, respect, engage and manage our natural systems for the benefit of all. I look forward to a future full of this renewed exploration, led by a team of 5 million, through which I hope we will gain a deeper appreciation for the wonderful complexity of our natural world and, in particular, what makes Aotearoa New Zealand special.” Read full acceptance speech.
For significantly advancing understanding in animal sciences, earth sciences or plant sciences.
To Neil John Gemmell for his research into understanding animal ecology and evolution, and the development of new approaches for the conservation and management of the world’s rarest species.