Scientists have taken a huge leap forward in understanding how sex is determined in reptiles, thanks to complete genome sequences of each genetic sex representative of the Australian central bearded dragon (Pogona vitticeps).
Published side by side in the journal GigaScience, the studies were carried out by teams in China and Australia, each using cutting-edge sequencing technologies. Despite their different approaches, both groups independently landed on the same surprising result: a gene called Amh may be the long-sought master switch that decides whether a bearded dragon develops as male or female.
The central bearded dragon is not just a favourite pet and icon of the outback—it also has one of nature’s strangest quirks. Its sex is usually set by chromosomes, like in humans. But in hot conditions, the rules change: genetic males (ZZ) can turn into functional females. This unusual system has made the dragon a powerful model for solving the mystery of reptile sex determination.
For the first time, researchers now have near-complete “telomere-to-telomere” genomes for both male and female dragons. The Chinese-led team, from BGI, sequenced a male using their brand-new CycloneSEQ nanopore technology—the first time this platform has been used to publish an animal genome. The Australian team, led by the University of Canberra with support from Bioplatforms Australia’s AusARG initiative, sequenced a female using a combination of the latest long-read technologies.
Together, the two projects provide an unprecedented look at the dragon’s DNA, unlocking sections of the genome that were previously impossible to study. Professor Arthur Georges, who led the Australian effort, said the new resources will supercharge reptile biology research: “We anticipate accelerated research in other areas arising from these assemblies, from brain and cranial development to gene-environment interactions in sex determination.” Dr Qiye Li, senior author of the Chinese study, said their choice of species had special significance: “We chose the bearded dragon because 2024 was the Year of the Dragon in China. Our new sequencing technology has given us insights that were out of reach before.”
By spotlighting Amh and its partner gene Amhr2, the studies bring researchers closer than ever to answering a fundamental biological question: how do animals decide whether to develop as male or female?
The findings also highlight the power of global collaboration: two teams, two genomes, two technologies—working in parallel to illuminate one of nature’s most fascinating mysteries.
A joint webinar with the lead authors will be held on 26 August 2025 to discuss the findings: https://cassyni.com/events/SWHReTL1j8YPEvxnLsyKYq
Links to research papers:
Guo Q, Pan Y, Dai W et al., A near-complete genome assembly of the bearded dragon Pogona vitticeps provides insights into the origin of Pogona sex chromosomes. GigaScience 2025. https://doi.org/10.1093/gigascience/giaf079
Preprint version: https://doi.org/10.1101/2024.09.05.611321
Patel HR, Alreja K, Reis AML, et al., A near telomere to telomere phased genome assembly and annotation for the Australian central bearded dragon Pogona vitticeps. GigaScience 2025. https://doi.org/10.1093/gigascience/giaf085
Preprint version: https://doi.org/10.1101/2025.05.01.651798