Evolutionary adaptations of TRPA1 thermosensitivity and skin thermoregulation in vertebrates

Altering skin color and reflectance is crucial for temperature regulation in poikilothermic vertebrates, while less so in homeotherms like birds and mammals, which evolved feathers, fur, and other insulation for endothermy. Heat-sensing in vertebrates relies primarily on Transient Receptor Potential (TRP) channels, with certain channels (TRPA1) shifting thermosensitivity over evolution and others retaining heat sensitivity (TRPV1). Exploration of a role for TRP channels in skin physiology has largely focused on human pigmentation and overlooked the evolution of different thermoregulatory structures in the integument of distinct vertebrates. For instance, colour/reflector pigment cells in ectotherms, fur and feathers in endotherms, hairless skin in hominids, and blubber in marine mammals. Therefore, we investigated whether a TRP channel mediates skin darkening induced by heat in the ectotherm Xenopus laevis and then explored the evolution of TRPA1 thermal sensitivity and its link with sk..., Embryos, drug treatment, and warm treatment
The Animal Care and Use Committee, University of Calgary, approved procedures involving frogs and embryos (AC21-0148; signed by Dr. Derrick Rancourt). Embryos were obtained by induced egg production from chorionic gonadotrophin (Intervet Canada Ltd.) injected females and in vitro fertilization according to the standard procedures (see protocols at Xenbase (http://www.xenbase.org)). Embryos were maintained at 16 °C in Marc’s modified Ringer’s (MMR) solution (100mM NaCl, 2mM KC1, 2mM CaCl2, 1mM MgCl2, 5mM HEPES, pH 7.4) until stage 43/44 (approximately 1 week) and staged according to Nieuwkoop and Faber on Xenbase (http://www.xenbase.org). The embryos were reared under light cycles of 12 h ON/ 12 h OFF (light =1000 lux or approximately 1.5 × 10–4W/cm2) on a white background. For experiments, the embryos were set in 35 mm dishes with 4 ml of MMR in a 16 °C or 32 °C incubator for the indicated times. A non-noxious warm temperature was chosen (32 °..., # Data from: Evolutionary adaptations of TRPA1 thermosensitivity and skin thermoregulation in vertebrates

Dataset DOI: [10.5061/dryad.wpzgmsc0t](10.5061/dryad.wpzgmsc0t)

Name: Gabriel E. Bertolesi

Institution: University of Calgary

Email: [[e-mail]](mailto:[e-mail])

## Description of the data and file structure

We analyzed the effect of temperature on the pigmentation of tadpoles (Fig 1; variable: pigmentation index in  File Figure 1 A, C and D). The effect on melanosome dispersion is analyzed on melanophores (MEX cells) in-vitro (Fig 2; variable: percentage of cells with dispersed melanosomes; File Figure 2). Those studies are analyzed again in response to TRP agonist and antagonist (Figure 4; File   Figure 4 in vivo and Figure 4 in vitro) as well as after transfection with siRNA for TRPA1 (Figure 5; File Figure 5). An evolutionary analysis of TRPA1 is performed in the second part of the manuscript.

Figure_1_D.txt: Kinetic from 16 to the indicated tempera...,