“To see, is to believe.”
That is one of the many mantras of scientific inquiry. Although many scientific theories do not require visual proof, a picture is still worth a thousand words.
For molecular biologists, being able to see literally where protein molecules are localized within the cell had been a dream. Until Martin Chalfie in the 1990s realized the potential of using green fluorescent protein derived from jellyfish (which was discovered by Osamu Shimomura in the 1960s), as luminuous genetic tag. This means that by splicing the GFP jellyfish gene into a target gene in the cell, you would then create a chimeric gene whose protein product will be made up of the target protein tagged with GFP. When this is then illuminated at specific wavelength of UV light, the GFP tag will fluoresce.
So if you tag a protein that is expressed in the skin with GFP, you will have something like this:
A glow in the dark mouse!
“What for?” I’m sure you are asking and wondering why you’d like your mouse glow in the dark. In developmental biology, specifically in embryogenesis, these technique can be applied in understanding biological events such as migration and movement of primordial cells, and how they mature into the type of cell they are destined to be. Understanding these basic processes are important in solving many human diseases which have root causes in abnormal developmental stages.
Roger Tsien expanded the palette of colors available for life scientists. In a Nature publication just last year, a team of scientists succeeded in “colouring” brain cells with up to 90 different colours, enabling them to see individual cellular interactions, which could pave the way in understanding neuronal circuitry. The technique is aptly called “Brainbow”:
For their “colorful” work, this year’s Nobel Prize in Chemistry is equally-shared by Shimomura, Chalfie and Tsien.