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.
The latest Dr. Anole…but not for long! Stroud wowed a packed house at Florida, regaling the audience with four chapters of research, two of which are already published in Annual Review of Ecology, Evolution & Systematics and Invasion Biology (2 of the ca. 40 papers he published during his time at FIU. The self-proclaimed highlight of his work? Publishing on T. rex!
Congratulations, James!
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.
Powered by WordPress & Theme by Anders Norén
