Congratulations! It's a... dragon?

The central bearded dragon (Pogona vitticeps) is a species of lizard with a flattened body, entirely covered by specialized scales. These lizards got their name due to their ability of making their throat look like a beard by inflating and puffing it out as well as the ability of their throat to turn to black when threatened.

Photo Description – The Central bearded dragon (Pogona vitticeps). Photo credits: David Cook [Public domain], via flickr.com

The central bearded dragon is an opportunistic omnivore widely distributed over eastern and central parts of Australia, found from the southeastern Northern Territory to the eastern part of southern Australia. They live in very diverse habitats including desert, dry forests and scrublands. Normally, these animals are diurnal. The central bearded dragon is an excellent climber, often found perched in bushes as well as on branches of trees and fence posts, spending as much time perching as it does on the ground. They are not social animals, though sometimes they congregate into groups to feed and bask.


Today we share a chromosome-length genome assembly for the central bearded dragon based on a draft assembly by Georges et al. GigaScience (2015). This draft was scaffolded with data donated by Norman, a central bearded dragon from Houston Zoo. Check out the interactive Hi-C contact map for the 16 chromosomes of the central bearded dragon below!

Central bearded dragon is one of the only two species of squamates (scaled reptiles) that has what's called genetic sex determination with overriding thermal influence (the other one being the eastern three-linked skink). (The lack of species with unambiguously identified sex reversal is not necessarily a reflection of this being a rare trait among reptiles as it is difficult to detect and document.) A study in 2015 has demonstrated that when eggs are incubated at temperatures above 32 °C (90 °F) some genetic males are born female! (1)


We hope that improvements to the bearded dragon reference genome assembly will improve genomic resources available for studying sex reversal in the species, help explore its prevalence and evolutionary implications in the current climate change landscape of rising temperatures.


Citations

Holleley CE, O'Meally D, Sarre SD, Graves JAM, Ezaz T, Matsubara K, Azad B, Zhang X, Georges A. (2015). "Sex reversal triggers the rapid transition from genetic to temperature-dependent sex". Nature. 523 (7558): 79‒82. doi:10.1038/nature14574

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