Professor of Biology and Director of the Living Earth Collaborative at Washington University in Saint Louis. I've spent my entire professional career studying anoles and have discovered that the more I learn about anoles, the more I realize I don't know.
In an event probably unprecedented in anole history, two new anole doctors will emerge tomorrow. After a multi-year incubation, AA stalwarts Kristin Winchell and James Stroud will hatch tomorrow almost simultaneously. James will get the festivities rolling at 11 a.m. eastern time in Miami:
Kristin follows shortly thereafter at 1 p.m. in Boston:
By this time tomorrow, the ranks of Dr. Anolis will be increased by two. Congratulations Kristin and James!
Anolis carolinensis on Kauai. Photo by Jonathan Losos.
Green anoles (A. carolinensis) have been introduced to a number of Pacific islands, including Hawaii. In a recent paper in Current Herpetology (published by the Herpetological Society of Japan), Goldberg and Kraus examine the reproductive cycle of Hawaiian green anoles and find it very similar to what occurs in their native range.
Here’s the abstract of the paper:
Reproduction was studied in an invasive population of Anolis carolinensis in the Hawaiian Islands, USA. Timing of events in the reproductive cycle was similar between A. carolinensis populations in Hawaii and native populations of the species in the southeastern United States. In Hawaii, males of A. carolinensisundergo a prolonged period of spermiogenesis (sperm formation) starting in November (n=1) and December (n=1) and continuing into August. Gravid A. carolinensis females in Hawaii (n=40) produce one egg in continuous succession from March into August. Reproductive activity in A. carolinensis in Hawaii ceased prior to the colder, wetter, winter months.
A press release from Arizona State University:
January 30, 2018With the hope that someday scientists will advance regenerative therapy in humans, an interdisciplinary team of researchers from Arizona State University and two other institutions has discovered important new clues in exactly how lizards regenerate their tails.
The findings appear in a pair of studies published in a Jan. 15 special issue of the journal Developmental Biology that focused on regeneration. The University of Arizona College of Medicine-Phoenix and Victor Chang Cardiac Research Institute also participated in the studies.
A green anole lizard (Anolis carolinensis). Photo: Kenro Kusumi.
In one paper, scientists from ASU investigated the role of a muscle stem cell population called “satellite” cells. Regeneration involves making new muscle, cartilage and tendons and requires cells that will become these tissues in a regrown tail.
The researchers found that the muscle satellite cells in green anole lizards (Anolis carolinensis) do double duty and can become cartilage as well. This study provides the first functional description of this stem cell population in lizards.
“Satellite cells are a unique stem cell population that allows humans to grow and repair muscle tissue,” said senior author Jeanne Wilson-Rawls, associate professor with ASU School of Life Sciences. “Mammals, including mice and humans, have muscles that contain these cells. After an injury, these satellite cells can repair the remaining muscle, but they cannot replace lost muscle in humans, unlike in lizards.”
“Using cell culture techniques, we found that lizard satellite cells behave the same as mouse satellite cells,” said Joanna Palade, lead author of the first paper and graduate student in the ASU molecular and cellular biology graduate program. “However, while both cell types can differentiate into muscle, only lizard satellite cells can turn on the genes and proteins required to make cartilage.”
By studying the genetic programming in mice and lizards, the researchers hope to find the differences between them that make the lizard more capable of regeneration.
“Lizards and humans have most of the same genes,” said Kenro Kusumi, co-author of the study and professor with the school. “Working with expert computer scientists, we found the genes that control cartilage formation were turned on in lizard but not mouse satellite cells, pointing to the existence of a possible switch that must be activated for regenerative therapies.”
In a second study, the scientists found that nerve regeneration in particular, is a critical part of the tail regeneration process.
“Nerve regrowth is immediate in the regenerated lizard tail,” said Cindy Xu, co-author of the paper and also a graduate student in the program. “Regenerating nerves quickly repopulate the tail as muscle begins to form. As the neuromuscular junction matures, the nerves are pruned back but remain more numerous when compared to the original tail.”
In this study, the researchers allowed lizards to regenerate their tails up to 250 days and then studied the neuromuscular junctions — the connections between nerve and muscle — at different stages. Coordinated tail movements require effective communication between neurons and tail muscles through these neuromuscular junctions resulting in muscle contraction.
“Overall, we found that the regeneration of neuromuscular junctions in the lizard followed a pattern similar to development in mice and humans,” said Minami Tokuyama, co-author of the paper and former research technician in Kusumi’s lab. “However, the regenerated muscle ends up with a greater density of neuromuscular junctions, and studying these differences may be important in developing future therapies for humans.”
Together, these findings may bring researchers closer to solving the challenge of creating the capability for limb or organ regeneration in humans.
The research team included Kusumi, Palade, Tokuyama, Wilson-Rawls and Xu, as well as Jason Newbern and Alan Rawls, who are faculty with ASU’s School of Life Sciences; Rebecca Fisher with ASU School of Life Sciences and the University of Arizona College of Medicine-Phoenix; and Joshua Ho and Djordje Djordjevic from Victor Chang Cardiac Research Institute. The National Institutes of Health funded this research through grants.
A female green anole from Hahajima in the Osagawara Islands.
We’ve had a series of posts about the anoles of the Osagawara Islands, of Japan, the “Galápagos of the Orient” [1, 2]. Now a new paper (pdf here) from Masakado Kawata’s lab has resequenced genomes of multiple individuals and measured morphology to assess how large the founding population was and what sorts of morphological changes have occurred since colonization, as well as identifying some genes potentially under selection.
Here’s the abstract:
Invaded species often can rapidly expand and establish in novel environments through adaptive evolution, resulting in devastating effects on native communities. However, it is unclear if genetic variation at whole-genomic levels is actually reduced in the introduced populations and which genetic changes have occurred responding to adaptation to new environments. In the 1960s, Anolis carolinensis was introduced onto one of the Ogasawara Islands, Japan, and subsequently expanded its range rapidly throughout two of the islands. Morphological comparison showed that lower hindlimb length in the introduced populations tended to be longer than those in its native Florida populations. Using re-sequenced whole genomic data, we estimated that the effective population size at the time of introduction was actually small (less than 50). We also inferred putative genomic regions subject to natural selection after this introduction event using SweeD and a method based on Tajima’s D, π and FST. Five candidate genes that were potentially subject to selection were estimated by both methods.The results suggest that there were standing variations that could potentially contribute to adaptation to nonnative environments despite the founder population being small.
Looks like it’s time for an updated compilation of anole covers! This one’s from the December 2017 issue of Mesoamerican Herpetology. Here’s what they have to say:
Javier Sunyer is a Spanish herpetologist who has lived in the Neotropics for the last 20 years. His work includes over 80 scientific papers and notes, dealing mostly with the distribution, natural history, and conservation of the Nicaraguan herpetofauna. Currently, he is a Research Associate at the Universidad Nacional Autónoma de Nicaragua-León (UNAN-León) and an Associate Editor/Section Editor for Mesoamerican Herpetology. Pictured on our cover is an image of Kempton’s Anole (Norops kemptoni), photographed in January 2006 at Alto Chiquero, Parque Nacional Volcán Barú, Provincia de Chiriquí, Panama. Adult males are territorial, and often display their colorful dewlap to intruders.
A, wattsi is one of five introduced species on the islands. A new report in Living World: the Journal of the Trinidad and Tobago Field Naturalists’ Club, indicates that it’s on the move.
Go to the Anole Annals calendar site on Zazzle.com, use this code:
NYESSENTIALS
Discount until midnite Pacific time on January 11.
Bryan Stuart, Curator of Herpetology at the North Carolina Museum of Natural Sciences in Raleigh, recently posted this on Facebook:
And an important comment on the FB post from Jeff Beane, the department’s collections manager:
“And the neotype of Anolis carolinensis is now NCSM 93545.”
What a horrible way to go! We’ve reported on this before [e.g., 1, 2, 3], but not Folt and Lapinski have published a nice review in Phyllomedusa of wandering and orb weaver spiders eating frogs and lizards in Costa Rica.
From the pages of the San Angelo Standard Times:
Living in the day and age where memes on social media are the prevailing means of communication does have a FEW benefits. I can almost always count on having a good laugh daily at something someone has posted.
Just the other day, I saw a meme that stated, “I was not born in Texas, but I got here as fast as I could!” As a naturalist, all I could think about when I saw this posted was one particular species of lizard that has found its way here, and that species is the brown anole.
The brown anole (Anolis sagrei) is one of two species of anoles that currently reside in Texas, but this species is not native to this state. First established near Houston in the 1970’s, this species was known only from areas around Houston, San Antonio and Brownsville as late as the turn of the century.
However, now it can be seen in and among most metro areas within an imaginary triangle that pinnacles in the DFW area, east of I-35 and west of I-45. It has only recently been observed (2016) in the Metroplex, and there have not been enough observations to verify whether there is a breeding population there or not. Even more recently, a smattering of individuals had been reported from a nursery in the city limits of Midland and these observations have been verified.
Originally native to the Bahamas and Cuba, this species has been introduced and is thriving in areas outside of Texas as well. It is arguably the most common lizard observed throughout the southern 2/3 of Florida, and it can also be seen throughout the eastern seaboard of Mexico.
The habitats that this invasive lizard prefers are settings in densely vegetated areas. Although occasional specimens are discovered basking and foraging in short shrubs and trees, the vast majority of sightings are of individuals in terrestrial settings. It is the propensity for living among ornamental plants and shrubs that has enabled this species to thrive in the warmer climates outside of its natural range. Therefore, many Brown Anoles are observed living around landscaped human habitations such as houses and even businesses.
The brown anole is among the most plainly colored and yet most intricately patterned lacertilian species in the United States. Unlike the native green anole (which can vary in coloration from green to tan to brown), this anole is always a shade of brown. The scales on the back are small and granular in appearance and texture, and females are often plainly patterned, adorned only with a light stripe that runs lengthwise down the spine. Males on the other hand are patterned with an intricate array of lightly outlined dark wedges and blotches along the spine.
Both species have varying amounts of dark striping that extends behind the eyes. Males have a brightly colored dewlap that, when extended, is dark red. The limbs are long, and are often colored patterned with dark stripes or bands. The head is not nearly as elongated like the green anole and is not noticeably separated from the body, and the tail, which is colored like the back, is about one-half of the 8-inch total length.
Brown anoles, like other lizard species, are “cold-blooded”, or ectothermic. This means that it does not generate heat from the inside of their body, as mammals and birds do, but rather is dependent on outside sources for heating and cooling. It is active during the early mornings and late afternoons from early April to October, and like many other reptile species it avoids the hottest part of the day by resting in shaded areas. However, the fact that it resides primarily in tropical areas, it is often active throughout the year.
This species of lizard is an opportunistic carnivore, feeding primarily on small insects such as moths, butterflies, crickets, grasshoppers, beetles, and the like.
The brown anole is oviparous, which is a fancy way of saying that it lays eggs. During the breeding season, which typically begins in early spring and extends into late summer, males will attempt to attract females by extending his bright red dewlap (a flap of skin underneath the chin) while bobbing his head up and down in a “push-up” manner.
Following successful copulations, the female will begin to lay clutches of a single egg. By laying an egg about every two weeks, a female can lay as many as 12 eggs in a season. These eggs are laid in areas of high humidity, and typically will hatch in about five weeks. The two-inch long hatchlings are smaller imitations of the female, and are capable of fending for themselves immediately.
This lizard species is a gregarious basker and will often allow people to get rather close as it relies upon its coloration for protection. However, once it feels an intruder has approached too close for comfort, it will quickly dart for cover among the leaf litter.
Michael Price is owner of Wild About Texas, an educational company that specializes in venomous animal safety training, environmental consultations and ecotourism. Contact him at wildabouttexas@gmail.com.
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