The green anole, Anolis carolinensis, is one of over 400 species in the genus Anolis (anoles) and one of over 11,000 species in the group Squamata (squamates). Squamates (lizards and snakes) are the most speciose groups of terrestrial vertebrates on earth. Native to the south-eastern United States, the green anole is known and loved for its vibrant green color and charismatic behavioral displays: during the summer months, male green anoles can be seen walking up walls using their sticky toe-pads, or elsewhere prominently perched in gardens and foliage, furiously doing pushups and extending a flag-like flap of bubblegum pink skin under their chin called a “dewlap.”
These characteristic displays are directed at any males that have invaded their territory, as well as any receptive females that catch their powder-blue eyes. Though males are most likely to be spotted displaying, females also perform these displays. Male and female anoles can be differentiated by differences in overall adult body size but also by the size of their dewlap, (males being larger in both cases). Though named for their gorgeous green hue, green anoles also change color to a silver-y brown. Likely not a camouflage technique, this behavior may correspond instead with environmental or social cues.
Anoles are particularly well studied because of their interesting evolutionary quirks. The genus is often described in textbooks as an example of convergent evolution, a process in which similar traits evolve in different species as a result of similar environmental conditions and not due to evolution from a shared common ancestor. Convergent evolution of morphology, physiology, and behavior has been well characterized in anoles and this group is an important model for understanding evolutionary processes. Anoles thrive in a lab setting, making it easy to adapt modern scientific tools and techniques for use in this system. Recently, CRISPR genome editing was used for the first time in a closely related species, the brown anole (Anolis sagrei), making it the first non-avian reptile to have genome editing capabilities be made available.
The genome for green anole, Anolis carolinensis, was first published in 2011 by Jessica Alföldi et al., and was the first non-avian reptile genome to be sequenced. Since its publication and re-annotation in 2013, the genome has been used widely for studies in evolution, genetics, and development. With over 600 citations, the original publication of this genome transformed the ability of researchers to study the evolution vertebrates.
Today, we share a few tweaks to the existing green anole assembly (AnoCar2.0) including anchoring suggestions for 4 microchromosomes missing in AnoCar2.0. We also share the Hi-C data generated using a fibroblast cell line from a female anole individual, originally frozen back in 1981! We thank Drs. Asha Multani, Sen Pathak, Richard Behringer, Liesl Nel-Themaat and Arisa Furuta in the Department of Genetics at the MD Anderson Cancer Center for sharing this cell line.
This is the 6th member of the Squamata family we've released here on the DNA Zoo Blog, see others here! Browse the 18 chromosomes of the green anole in the interactive JuiceBox.js session below. Note an inversion polymorphism in HiC_scaffold_1: stay tuned for more data to find out if this is a culturing artifact or a primary sample polymorphism.