A developmental shift in venom toxin expression underpins a major prey switch in Australian brown snakes.
12 affiliations
- 1Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, United Kingdom.
- 2Institute of Biology Leiden, Leiden University, Leiden, 2333 BE, The Netherlands.
- 3Present address: Howard Hughes Medical Institute and Department of Biology, University of Maryland, College Park, 20742, United States of America.
- 4Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado, Aurora, 80045, United States of America.
- 5Venom Supplies Pty. Ltd., Tanunda, SA, 5352, Australia.
- 6Division of Bioanalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, 1081 HV, The Netherlands.
- 7Department of Biological Sciences, University of Northern Colorado, Greeley, CO, 80639, United States of America.
- 8Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, 117558, Singapore.
- 9Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore.
- 10Department of Cellular, Molecular and Genetic Medicine, Virginia Commonwealth University, Richmond, 23298, United States of America.
- 11Australian Venom Research Unit, Department of Pharmacology and Therapeutics, University of Melbourne, Melbourne, VIC, 3010, Australia. [email protected].
- 12Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, United Kingdom. [email protected].
Abstract
Background
Many animals change traits over the course of their life history. It has been proposed that some of these developmental changes evolve in concert with shifts in ecology, but there are relatively few clear examples, and identifying the underlying molecular changes is challenging. Australian brown snakes (Pseudonaja spp.), one of Australia's most venomous snakes, may provide such an example, as previous work has shown that these species undergo a dietary shift from reptiles to mammals, accompanied by differences in venom activity.Results
We show that the venom composition of adult brown snakes is distinguished by the collective expression of four procoagulant toxin families, which are absent in juvenile life stages, where venom composition is instead dominated by neurotoxins. The developmental onset of expression across all four procoagulant toxins correlates with a functional shift in venom activity to one that disrupts the blood-clotting system of mammalian prey. We further show that this developmental timing in both toxin expression and procoagulant venom activity coincides with a broader ecological transition in which Australian brown snakes begin to prey on mammals. In contrast, we found that the smallest brown snake species, a lizard specialist throughout its lifetime, only expresses neurotoxins and shows no comparable developmental shift in either procoagulant toxin expression or procoagulant activity.Conclusion
Our findings suggest that a coordinated shift in the expression of four procoagulant toxin gene families transitions the venom from a neurotoxic phenotype in lizard-feeding juveniles to a potent procoagulant phenotype in mammal-feeding adults. These results provide a clear example of how the concerted upregulation of multiple genes can drive a functional shift in a key ecological trait, linking changes in toxin gene expression to venom activity and, ultimately, to prey-capture strategy.
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BibTeX
@article{thiel2026developmental,
title = {{A developmental shift in venom toxin expression underpins a major prey switch in Australian brown snakes.}},
author = {Jory van Thiel and Cara F Smith and Taline D Kazandjian and Rohit N Patel and India C Cullen and Stephanie French and Rachael Da Silva and Laura-Oana Albulescu and Nathan Dunstan and Jeroen Kool and Michael K Richardson and Stephen P Mackessy and Nicholas R Casewell and R Manjunatha Kini and Anthony J Saviola and Timothy N W Jackson and Cassandra M Modahl},
journal = {BMC biology},
year = {2026},
month = jul,
doi = {10.1186/s12915-026-02699-0},
url = {https://europepmc.org/article/MED/42928320},
note = {CC BY},
}
RIS
TY - JOUR
TI - A developmental shift in venom toxin expression underpins a major prey switch in Australian brown snakes.
AU - Jory van Thiel
AU - Cara F Smith
AU - Taline D Kazandjian
AU - Rohit N Patel
AU - India C Cullen
AU - Stephanie French
AU - Rachael Da Silva
AU - Laura-Oana Albulescu
AU - Nathan Dunstan
AU - Jeroen Kool
AU - Michael K Richardson
AU - Stephen P Mackessy
AU - Nicholas R Casewell
AU - R Manjunatha Kini
AU - Anthony J Saviola
AU - Timothy N W Jackson
AU - Cassandra M Modahl
PY - 2026
DA - 2026/07/25
JO - BMC biology
DO - 10.1186/s12915-026-02699-0
UR - https://europepmc.org/article/MED/42928320
AB - Background Many animals change traits over the course of their life history. It has been proposed that some of these developmental changes evolve in concert with shifts in ecology, but there are relatively few clear examples, and identifying the underlying molecular changes is challenging. Australian brown snakes (Pseudonaja spp.), one of Australia's most venomous snakes, may provide such an example, as previous work has shown that these species undergo a dietary shift from reptiles to mammals, accompanied by differences in venom activity.Results We show that the venom composition of adult brown snakes is distinguished by the collective expression of four procoagulant toxin families, which are absent in juvenile life stages, where venom composition is instead dominated by neurotoxins. The developmental onset of expression across all four procoagulant toxins correlates with a functional shift in venom activity to one that disrupts the blood-clotting system of mammalian prey. We further show that this developmental timing in both toxin expression and procoagulant venom activity coincides with a broader ecological transition in which Australian brown snakes begin to prey on mammals. In contrast, we found that the smallest brown snake species, a lizard specialist throughout its lifetime, only expresses neurotoxins and shows no comparable developmental shift in either procoagulant toxin expression or procoagulant activity.Conclusion Our findings suggest that a coordinated shift in the expression of four procoagulant toxin gene families transitions the venom from a neurotoxic phenotype in lizard-feeding juveniles to a potent procoagulant phenotype in mammal-feeding adults. These results provide a clear example of how the concerted upregulation of multiple genes can drive a functional shift in a key ecological trait, linking changes in toxin gene expression to venom activity and, ultimately, to prey-capture strategy.
SN - 1741-7007
ER -