As we have posted previously, the Glor lab has been breeding anoles to assess the degree of reproductive isolation between A. distichus-clade lineages. Most eggs we collect fall into two easily separated categories: white, calcified, viable eggs; and yellow, uncalcified, inviable eggs. On occasion we get a third type: white, seemingly viable, yet uncalcified eggs. These represent only about 1% of the eggs in our current experiment. We always incubate these, in the hopes that they will develop, but typically they mold early in incubation and, upon dissection, show no signs of fertilization or development. The egg above is our first exception which, when incubated for about 3 weeks, was clearly developing (it has, sadly, since died).
So, AA community, has anyone else seen anything like this? I would very much like to hear your thoughts, interpretations and comments.
- John David Curlis - March 1, 2022
- Joe Macedonia - January 31, 2022
- Lindsey Swierk - January 27, 2022
Rich Glor
It would have been pretty sweet if this egg survived and we were able to watch the whole process. It seems unlikely that we’ll get many more eggs like this; based on the number of eggs we’ve had over the past two years, this egg is something like a 1 in ~3,000 occurrence!
James Stroud
Wow! Impressive figures. What is your hatching success (%) like?
Anthony Geneva
James – thanks! Lots of people, particularly fellow graduate students Julienne Ng and Dan Scantlebury, have been instrumental in getting our protocols established and humming along. To answer your question 1826 of the eggs we have collected in the last two years were viable (e.g. not slugs) and of those about 77% have hatched.
James Stroud
Incredible, that sounds like a fantastic breeding colony. The 1826 eggs were from how many reproductive females? (roughly, of course!)
Anthony Geneva
About 150 females each year.
Daniel Scantlebury
Theoretically speaking, it might be possible to use a combination of plastics and surgical glue to make tiny windows and peer in on anole development.
Peter Mudde
I did that once with an turtle egg.. A bit larger and more calcified.. But it worked..
Thomas Sanger
We have found that when you “window” an anole egg the pressure inside the egg from the developing embryo eventually forces bit of tissue out of the window where they rapidly desiccate and die. Its far easier to just remove the entire shell and to subsequently grow the embryo in a dish with cell culture media.
Anthony Geneva
Cool. How far along have you been able to get embryos to develop? I’ve seen this done with chicken eggs out to just before full development but the eggshell itself is somehow required for survival, in other words, you can’t hatch a chicken grown in saline. Have you found the same with anoles?
Thomas Sanger
To be honest, we haven’t tried to optimize the protocols for long-term culture. That’s not the point of this experiment at the moment. But with only a little effort we were able to keep the embryos alive and developing for 10-14 days. In terms of the embryo, this takes it from a stage without limb buds through stages that look like a recognizable lizard. (I should also note that by “we” I am referring to work primarily done by one of my collaborators who has previous experience with tissue culture techniques.)