27. Subcellular basis of climate change resilience in oysters

Priscila Goncalves (1,2)*, Emma L. Thompson (1,2), David A. Raftos (1,2)

1 Department of Biological Sciences, Macquarie University, NSW 2109, Australia.
2 Sydney Institute of Marine Science, Chowder Bay, NSW 2088, Australia.

Background
Climate change is increasing the acidity and temperature of the world’s oceans. This changing ocean is particularly damaging to oysters because the integrity of their shells and other energy-demanding processes are hampered by shifts in water chemistry. Although adaptation to climate change is possible for many marine species, the molecular basis of heritable climate change resilience is largely unknown. My PhD research aims to discover the biological mechanisms that provide heritable protection against the deleterious effects of climate change in oysters.

Methods
I am exploring the differential responses to climate change stressors of two genetically distinct populations of Sydney rock oysters (Saccostrea glomerata). Selectively bred and wild-type (non-selected) oysters were exposed to elevated (predicted for 2100) or ambient (current) CO2 conditions over one or more generations. After CO2 exposure, their intracellular responses were assessed using- a combination of molecular techniques, including transcriptomics (RNA sequencing and qPCR) and proteomics.

Findings
I have identified biological processes affected by ocean acidification that might also be associated with adaptation to these conditions. Single and transgenerational exposures to CO2 stress altered the expression and abundance of a number of genes and proteins involved in multiple cellular functions. Such adaptive responses differ between oyster populations.

Conclusions
As a result, this project provides a functional framework to explain the molecular basis of acclimation to ocean acidification in oysters. Our findings reveal the biological functions that may enable marine calcifiers to cope with such stressful conditions in the face of climate change.