A/Professor Sandie Degnan
Research area - evolutionary and ecological genomics of marine invertebrates.
Animal genomes interact with heterogeneous environments in multiple ways that we are only just beginning to understand. The outcome of these molecular-level interactions during animal development is the evolution across space and time of an astonishing array of phenotypic diversity. Nowhere is this more apparent than on coral reefs. Applying field and laboratory experimental approaches to diverse coral reef invertebrates, we integrate functional genomics and developmental biology with population and behavioural ecology to reveal the pattern and process of evolution in the ocean. We focus on the early life history stages of dispersive embryos and larvae, because the ways in which they sense and respond to their environment are crucial to the survival, connectivity and evolution of marine populations. Analysis of diverse genetic programs – including cell and environmental signalling, innate immunity and circadian rhythms – helps us to better understand how marine species evolve under natural and accelerated environmental change.
Current projects include:
Larval recruitment and local adaptation across heterogeneous habitats. We combine modern genomic techniques with phylogeography and larval behaviour to make evolutionary and ecological inferences about the role of variation in gene expression among individuals, families and populations.
The role of the innate immune system in the origin and regulation of larval settlement. We are exploring the hypothesis that interactions between microbes and the embryos of ancestral animals drove the co-evolution of the innate immune system and the pelagobenthic life cycle.
Origin and evolution of the metazoan pelagobenthic life cycle. We contribute to theoretical discussions on the hypothetical ancestral state of all living animals.
Germ line development, sexual reproduction and sexual differentiation in marine invertebrates. We take a holistic approach to understanding sexual reproduction in the ocean, from developmental origins of the germ line, through to parentage analysis of individual larvae.
Ecological and invasion genomics. We use a native coral reef ascidian, with a penchant for colonising man-made harbour habitats worldwide, as a model for studies of the phenotypic plasticity necessary for recruitment into non-native habitats.
The origin and function of the enigmatic octocoral mitochondrial MutS gene. We are interested in the origin and function of this unique gene, and how its presence might affect deep vs shallow water metabolism in this exclusively marine group of animals.
The essence of being an animal: allorecognition and the evolution of individuality in a basal metazoan, the sponge Amphimedon queenslandica. We integrate genomic, population genetic, immunological and developmental studies to understand how animal cells recognise self from nonself.
Marine biotechnology in aquaculture. We apply genomic and molecular methods to questions of larval settlement, growth and reproduction of commercially important tropical aquaculture and biofouling species.
Hentschel U, Piel J, Degnan SM, Taylor MW. (2012). Genomic Insights into the Marine Sponge Microbiome. Nature Reviews Microbiology 10: 641-654.
Heyland A, Degnan SM and Reitzel A. (2011). Emerging Patterns in the Regulation of Marine Invertebrate Settlement and Metamorphosis. In Mechanisms of Life History Evolution (T Flatt and A Heyland, eds). Oxford Univ Press, Oxford.
Bilewitch JP and Degnan SM. (2011). A unique horizontal gene transfer event has provided the octocoral mitochondrial genome with an active mismatch repair gene that has potential for an unusual self-contained function. BMC Evolutionary Biology 11: 228. doi: 10.1186/1471-2148-11-228
Degnan SM and Degnan BM. (2010). The initiation of metamorphosis as an ancient polyphenic trait and its role in metazoan life cycle evolution. Phil Trans Royal Soc B 365: 641-651
Srivastava M et al. (2010). The genome of the demosponge Amphimedon queenslandica and the evolution of animal complexity. Nature 466: 720-726.