From left to right: Moss, African tree viper, fireflies
Green Fluorescent Protein? Luciferase? Chromatophores? Liquid Crystals? How are we going to get these cats to change color and, in what way? All through-out nature we see organisms manipulating the spectrum of light in many different ways. Some organisms absorb the energy from colored light to create sugars, some reflect specific colors to make themselves look hazardous, while others will emit bright colors in a flashy glow to let mates know what’s up.
Every color we see in nature has a purpose and/or reason for being the color that it is. Inside each of these organisms that change or emit color, there are specific mechanisms that they use to create the visual effect. All these mechanisms are exactly the ones we are investigating into to see if they will work with cats.
One of the most popular mechanisms is fluorescence, which happens through proteins, or other small molecules that can absorb and emit light. Fluorescent proteins and pigments absorb light and re-emit/reflect it as a different wavelength, or color. Many of the genes that are responsible for synthesizing these types proteins and pigments have been studied, which makes it easier to think about how we can use them in cats. However, one of the main problems with using fluorescence or chemical pigments is that cats don’t have chromatophores like this tiny blue-ringed octopus does. Chromatophores are specialized cells that hold, concentrate and control the activation of the reflective pigments. When they are activated these cells spread the pigment across their surfaces to create the visible effect.
Glowing or bioluminescence works differently from fluorescence. Bioluminescence works through two compounds interacting, instead of a single compound that absorbs/reflects light. That means we can trigger the visual effect in light or dark, and the mechanism is easier to activate. We can engineer the cells to produce luciferin and activate it only when the gene for the luciferase enzyme is triggered. This is a commonly used tool in research for studying cellular activity and also often found throughout the animal kingdom, like in fireflies, jellyfish, and glow worms. You can learn more about this mechanism here.
The third mechanism that we’ll introduce is structural coloration. Structural color works by using micro structures like tiny holes, scales, and crystals to reflect certain colors of light.
More about chameleon coloration here
These can change in more diverse ways than compared to the other types of coloration since it is these small structure changes that give the color. So rather than working with chemical and genetic mechanisms, we can work with one particular cellular structure and trigger it to make a color change instead of having the cells create new proteins or pigments to give a different color. But, there will still be a challenge in engineering a cat to grow these unique structures, which will be a lot more difficult than the few genes that would need to be altered to give fluorescence or bioluminescence.
These are some of the mechanisms that other animals use to change colour, but what will work best with cats? How do we trigger these mechanisms in response to radiation? I think that, with more research, we will find that there will be a lot of other factors that could influence the color of the ray cats more so than these organisms’ color changing methods. Next week’s post will be about radiation and more of the factors that we need to consider. We’ll start looking into some of the possible mechanisms of coloration via gamma rays.
Just as an end note to our introductory blog post I would like to say hello; my name is Zavier, I recently joined The Ray Cat team. I am a 16 year old bio-hacker from Vermont, I am hoping to act as a good scientific communicator for this project because I want to be able show people that you don’t need a piece of paper saying you know how to do something to do it. I hope you are looking forward to this project as much as I am, and are excited to discover more and more with Kevin, the Bricobio members, and I as we move forward. Please leave comments, feedback, questions or notes below!