Presented by Dr Erin Hahn & Dr Clare Holleley

CSIRO National Research Collections Australia

Recorded Wednesday 28 June 2023



Gene expression plasticity enables organisms to rapidly respond to changes in their environment. The degree to which such plasticity contributes to species’ resilience or vulnerability to change is currently unknown and this knowledge gap is hindering uptake of gene expression data in ecosystem monitoring. Historical gene expression data spanning the last century would accelerate study of how gene expression shifts might be involved in response to environmental factors. Museum specimens represent phenotypic snapshots spanning the last 150 years – a period of rapid environmental change. Unfortunately most specimens, especially those older than 20-30 years, were not preserved with RNA retention in mind. Therefore, we must seek alternative measures to infer historical gene expression to generate long-term time series data.



Drs Hahn and Holleley will share new capabilities they have developed from an unlikely source – formalin-preserved museum specimens. While formalin-fixation is generally viewed as a hindrance to analysing historical genomes, they have developed two complementary methods which harness historical fixation to characterise preserved epigenomes through measuring chromatin accessibility. These methods provide new capabilities to track the trajectory of temporal gene expression trends and increase the utility of formalin-preserved specimens that were previously considered sub-optimal genomic resources.

Pre-print of the study, Century-old chromatin architecture preserved with formaldehyde, is now available here: https://www.biorxiv.org/content/10.1101/2023.07.26.550239v1