Could Rudolph have a red glowing nose? (Suesa's Science challenge #3)

Hello dear Steemians,

This is my first post here on Steemit and while thinking about what to write about, I’ve come across @suesa’s contest that you can check over here. I found it very intriguing and since one of my interests are science in general and biology in particular, well, I accepted the challenge :)

Image 1. Pixabay

My focus was on Rudolph’s red nose of course. I wanted to see if I could provide some evidence that could at least make it biologically plausible and possible to achieve.

With this work, I intend to show you some examples and facts of the biological world that could possibly correlate to some of the requirements needed to achieve a reindeer’s glowing red nose.

So, first of all, it is important to make some questions about our subject, in order to know what arguments we need to find and formulate to support the claim that Rudolph could have a glowing red nose.

I’ll present it as if I’m having a dialogue with my mind. To me it made more sense this way.

Our case study:

Rudolph’s nose and only its nose is red and glows.

Questions:

1. Is there any evidence of an animal/mammal with a glowing red nose?

No.

2. Is there any evidence of a biological organism that glows?

Yes, many biological organisms have the ability to glow. This goes from several bacteria to a lesser number of animals, like the fireflies. The color range occurs mainly in the blue-green range. [1]

3. And in red color?

Yes, at least some sea fish are known to glow in that color range, at least to some extent. In particular the dragonfishes of three genera (Malacosteus, Pachystomias and Aristostomias). [2]

4. What are the mechanisms behind the glow?

There are at least two known mechanisms. Bioluminescence and fluorescence.

The former is capable of producing its own light derived from a chemical reaction where, in most cases, an oxidation of a light-emitting molecule occurs. This light-emitting molecule is called luciferin, while the reaction is catalyzed by an enzyme. Normally, it is a luciferase.

Fluorescence specific molecules, on the contrary, don’t produce their own light. They have to be excited first by a luminous source. So they take up photons (light particles) that excite their electrons to high level energy states, which rapidly release their energy by emitting light with a higher wavelength. [1]

5. So if Rudolph was to have a constant red glowing nose what would be the best mechanism?

Definitely bioluminescence. This way the glowing could be constant and auto-sufficient.

6. Ok, but how would this mechanism be transferred to Rudolph’s nose?

Well, it would be almost impossible, at least in a reasonable time frame, to try it with evolution by itself. Therefore, the most logical way would be by genetic engineering. At least the time frame could be much smaller.

7.
7.1. Then what requirements would we need to meet in order to at least experiment it? Basically what’s the plan?

Ok, so here we go. Let’s think a bit.

We need to know a bioluminescence pathway that we can test. So far, there are many different pathways described, but not that many have been genetically characterized. As a result, we’ll need to go with a known pathway just to exemplify the process.

For example, the bioluminescence pathway from the bacterium Vibrio fischeri. It produces blue light. But since there is evidence of red light bioluminescence on other organisms, then our argument is still valid, because it would still be possible scientifically. Maybe not in our current time period, but who knows in the future.

So, V. fischeri bioluminescence pathway is genetically organized as an operon. The lux operon. This means that the coding regions (ORFs) for the required enzymes responsible for the reaction are arranged juxtaposed to one another, like so:

Image 2. Lux Operon from V. fischeri

The ORFs luxC, luxD and luxE will generate the proteins responsible for the generation of luciferin. The precursors come from a fatty acid pathway present in most biological organisms.

The ORFs luxA and luxB will generate the sub-units of the bacterial luciferase which, as said above, will mediate the chemical/enzymatic reaction to produce light. [3]

We have some evidence that this works. This was tested by introducing this operon on a non-bioluminiscent bacterium (Escherichia coli). After that, the mutated E. coli was able to grow and glow. This also showed that the overall environment necessary for the reaction to occur was also already present in this bacterium. For example, precursors and co-factors. [4]

7.2. How will we introduce this genetic circuit into the reindeer’s genome?

This could be accomplished by using a technology called CRISPR-Cas9. We could target embryonic cells. [5]

7.3. But where in the reindeer’s genome would you introduce the circuit? Could it be placed anywhere?

Of course not, it would be impossible to place it anywhere. We cannot target regions where other genes are located. Otherwise there is a risk of disrupting crucial biological functions.

For this, at least two conditions have to be met.
1 - We need to study the reindeer’s genome to find a suitable neutral site. A region where there is no gene or important regulatory element.

2 – This neutral site needs to be near a region that we know will be accessible (uncondensed) within the targeted nasal cells. Where we want the circuit to be active.

To note that the operon on the circuit would need to be regulated under a promoter specific to the nasal cells. This could be achieved by studying the gene expression within this cell type. A promoter from one of the genes that are only expressed on these cells, naturally, could be used. That way, we knew the pathway would only be active on the reindeer’s nose. At least theoretically.

7.4. But what about the genome? Is it known?

Well, this comes just at the right time. A group of scientists have just published the reindeer (Rangifer tarandus)’s genome this month. There are many homologous ORFs to other similar mammals (which can be a starting point for the search), but also many new families of genes. [6] There is a lot of raw information that will need to be studied. It takes time. But it’s possible to search for what we need here.

8. This seems reasonable. But would it really work?

I don’t know. We would need to go by trial and error. You know, biology is a very unpredictable discipline. It’s true that you can predict the behavior of an enzyme in vitro, for example, and expect a known result. However, things change dramatically when we look at the biological organism as a whole.

For example, I want to express a certain gene for an enzyme that produces a certain substance. Although I know what the enzyme does. It is unpredictable to know the effect of its presence within the cell. Most of the time it’s hard to have the same result. Even if everything is done under the same conditions. One thing is the theory and the other is what you obtain when testing in the lab.

Therefore this would need a lot of iterative work. Test. Tweak. Test. Tweak. And this can be time consuming.

But as said before totally possible.

9. Wouldn’t that raise a lot of ethical issues? You know, engineering embryonic cells, wait for organism to grow and study it?

Sure! Imagine engineering an embryo. If everything goes reasonably well, you will only see the resulting baby reindeer after several months. Now, everything could go very well and it is healthy or everything can go really bad and it will be ill. And the latter is what happens most of the time, specially in the beginning of your research. So yes it would raise many ethical issues.

But, this was just an exercise to see if there is at least some scientific chance to achieve a reindeer with a glowing red nose.

I think the answer is yes. Even if the probability goes near 0%. At least there is some chances. But of course, it would take a lot of time. Time that I believe people wouldn’t invest into this.

But Santa who knows :)

9. To me it makes sense. But how would Santa have that kind of knowledge and technology if these Christmas stories have been around for so long?

Well, the only reasonable and scientific way I can imagine is by doing time travel. Yes, probably Santa came from the future already with Rudolph under his caring or at least with the tech and knowledge necessary.

As for time travel. Well, at least some renown scientists have considered it to be possible theoretically. [7]

So there you go :)

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Thanks @Suesa for the opportunity!

Thank you all for reading. Hope you liked it :)
Oh! And Merry Christmas!

Image 3. Pixabay

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Sources:

Image 1
Image 2
Image 3

1. Haddock, Steven; Moline, Mark; Case, James (2010) Bioluminescence in the Sea, Annu. Rev. Mar. Sci. 2:443-93
2. Herring, Peter; Cope, Celia (2005) Red bioluminescence in fishes: on the suborbital photophores of Malacosteus, Pachystomias and Aristostomias, Marine Biology 148:383
3. Yen-Cheng Lin, Leo; A. Meighen, Edward (2009), Bacterial Bioluminescence
4. Baker, J.; Griffiths, M.; Collins-Thompson, D. (1992) Bacterial Bioluminescence: Applications in Food Microbiology, Journal of Food Protection 55:62-70
5. Web article: What is CRISPR?, By Aparna Vidyasagar (2017)
6. Li, Zhipeng et al, (2017) Draft genome of the reindeer (Rangifer tarandus), GigaScience 6 12:1-5
7. Web article: The Physics of Time Travel, By Dr. Michio Kaku