Green morphs, new look on leopard gecko skin

[CarrotTail]

Hello,
I wrote some time ago about green/blue geckos why its not possible, but now its it published.

Ultrastructure and distribution of chromatophores in the skin of the leopard gecko (Eublepharis macularius) - Szyd?owski - 2015 - Acta Zoologica - Wiley Online Library

 

[warhawk]

What I could read sounded interesting. Were you able to work out what colors would be possible down the road?

 

[CarrotTail]

In the era of the present results blue/green colour is impossible to obtain in leopard geckos. Others study form fishes to reptiles showed that pigment cells origin are genetic conservative. Iridophores which are major component of blue/green colour in reptiles, have additional functions than only in pigmentation. Theoretical occurrence of iridophores in leopard geckos would require changes form genetic level (additional genes, additional part of DNA = largest chromosomes or their number), trough metabolic changes (nitrogen metabolism and temperature behavior) to big changes in sturcture of the skin. If that will happened we shoud ask do we have still the same species? In other observation unpublished I observed the same pigment cells in "green" ares of emarines as in wild type leopard geckos in areas between yellow and black dots (especially in young geckos when thery change pattern, one deeper layer of individual melanphores). In conclusion for now, without advance genetic engineering or hybridization colour morphs can do within melanophores and xanthophores. But according to studies on mammals in some specific way blue colour can be visible but on the other way. Not like structural iridophores dependent coloru but on physical reflection wavelenghts by connective tissue - maybe this is the way. Example of connective tissue can be visible in young leopard geckos wild types (especially skinny) or albinos. But this show only that thick layer of epidermis and dermis and their connective tissue can do optic illusion. Just that the individual will get fat (growth of adipose tissue under skin or on peritoneum) or grow (growth of adipose tissue under skin or on peritoneum, growth of connective tissue and epidermal epithelium). So the result may be only a temporary effect blue which we lack with age or better condition of gecko. According to blue belly etc. most important thing is that in this part (abdominal part of head, trunk and tail) there are no any kinds of chromatophores - only epidermal epithelium and connective tissue with blood vessels, fibroblasts, fibrocytes etc.

 

[geckolabs]

The notion that they completely lack iridophores seems to biased from the description of the sampling.

Were samples also taken from the skin of the head? From directly over the eyes themselves, not just a section elsewhere on the head. The blue coloration that exists over the eyes and brain as hatchlings/juveniles is a neuroprotective asset, and being directly associated with neural tissue, is likely a result of co-migrating neural crest cells producing iridophores opposed to the reflection of connective tissue. If it were the latter, the animals would, as you suggested, lose this coloration as they age and build fat reserves and adipose. But There are still examples of animals that maintain this blue into adulthood, even if covered by other pigmentation.

The color serves to protect the neural cells from UV damage while the animals other pigmentation develops. As such, it is likely that the distribution of them cannot really be significantly skewed from that area (ie, we cannot selectively breed to expand those finite domains), but the claim that they entirely lack them is not true just because they lack them in the general body.

Does the body lack them? The evidence suggests yes. But unless the head samples were the tissue directly above the eye/brain, I am not sure I am convinced they entirely lack iridophores. It is certainly a good study though, and finally gives a comprehensive view of what is present.

I do not follow neural crest research too heavily, as I focus on the neural plate. Do you know of any studies that directly look at the evolution of chromatophores and their origins and adaptations?

It would be interesting to see it taken further to see which chromatophores are still present in the various mutations (ie whether Albino "X" completely ablates melanophores, or if snow ablates xanthophores.) Though, I believe there was a study not long ago that looked at the presence of tyrosinase for the various albinos, and demonstrated that tyrosinase was present (which isn't a surprise given the coloration that can still be achieved), so melanophores should certainly still be present.

Are there plans to look at this further, to see if there are differences between the pigmentation arrangement of xanthophores relative to melanophores, and their spatial arrangements in regard to the superficial depth at which each type is found?

Also, there is a subtype of melanophore that exists in the vestibular canal that contributes to balance in mammals. Would it be possible, via these methodologies, to determine whether those cells exist in the leopard gecko's vestibular system, and if so, whether they are lost in Enigmas with severe Enigma syndrome?