Biofluorescence ā An Introduction By Me (Tigoteus, an amateur)
Chances are, you do not think about biofluorescence too often. At least, thatās the case if you arenāt regularly looking into microscopes or dissecting reef fish. Or you might be a bit like me ā meaning absolutely obsessed with the topic!Here are three statements regarding biofluorescence that are all true simultaneously:
- The discovery of the protein responsible for biofluorescent traits has singlehandedly revolutionised light microscopy during a time in which it was considered to slowly become āoutdatedā1.
- Not only that, but when scientists decoded the gene responsible for the protein it also revolutionised the medicine and biotechnology field2.
- Due to its role in natureās evolutionary arms race, one can say that some reef fish react to laser pointers (that are imitating biofluorescent hunting techniques) the same way cats would do ā but more on that later3.
Great! Now that you have a fantastic overview over what makes this one protein so special, letās take a step back real quick and go a bit into detail:
How exactly has this protein revolutionised light microscopy?
During my biology teacherās uni-years, light microscopy (LM for short) was largely considered dead or actively dying out. Why? Because electron microscopy (EM for short) was becoming more and more the industry standard!
Think about it: light microscopy has a resolution of about 200nm, while electron microscopy has one of 0,1nm4! Thatās a huge difference. However, everything that one wants to see through an electron microscope has to be, well, dead. There is no living thing one can see through an EM, since the slides must be specifically prepared. But when scientists in the 90s discovered that you can safely attach biofluorescence through its gene5 (the āgreen fluorescent proteinā, GFP for short) to other genes for other proteins, the game got a lot more interesting.
You see: DNA gets copied over and over and over again for every new protein you must make. You can decode the DNA, so that you know where which gene for which protein lies and you can attach the GFP safely onto it. The result? Fluorescent proteins!
And thatās pretty effective and very long lasting. Every new protein created from this specific DNA string has the GFP attached to it. You can now watch fluorescent proteins fumble around in your cells, without having to interfere with the cell any further. Transports, mechanisms, āinvisibleā/partly visible apparatuses like the cytoskeleton or the spindle apparatus can now be seen in a living cell6.
So, you know, a big day for biology, right?
But wait! That's not all: HIV-researchers used the gene in one of their experiments:
A potentially HIV-repelling gene together with the GFP was planted into cat egg cells. If the cat fluoresced, it meant the gene transplantation was successful! Or you can mark specific bacteria with the GFP6, or-
I think you get it. This fucker is versatile. Now, with that in mind, you will have no problems understanding part two: Shiny PokƩmon fish!
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Literature Sources
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Source A
A talk I had with my bio teacher during the 5-minute break, Iām sorry idk how to reference that properly šSource B
Schnetzer, Julia: Wenn Haie leuchten: Eine Reise in die geheimnisvolle Welt der Meeresforschung, 1st ed., Munich, Germany: hanserblau, 2021, S. 28-29.Source C
Elektronenmikroskop: on: Wikipedia, o. D., https://de.wikipedia.org/wiki/Elektronenmikroskop (visited on the 15.10.2022).