Although I’m approximately two years late in reporting about this discovery I still think it’s pretty cool. In 2013 Kumagai et al. for the first time discovered a fluorescent protein in a vertebrate, the Unagi eel. Until then fluorescent proteins had only been found in invertebrates, such as reef corals and the jellyfish Aequorea victoria, where the famous green fluorescent protein originally came from. My attention was drawn to this finding in a brief article in the Chemistry World journal, in which the author claims that, “Unagi’s status as a culinary delicacy means you’re more likely to encounter these eels in a restaurant than a lab”. [Picture copied directly from the article link.]
Apart from (presumably) tasting good and looking pretty, the fluorescent protein – called UnaG – from Unagi eels may be able to form the basis for a diagnostic test for liver disease. UnaG only fluoresces when bound to bilirubin, which is a break-down product of haem, the molecule that carries oxygen in the blood. Livers with impaired function have difficulty further processing the bilirubin before it is excreted, leading to a build-up of bilirubin in the body, and in extreme cases to jaundice. So the intensity of UnaG fluorescence can be used as a read-out for how badly the liver is damaged.
And now for something completely different: next time I’ll be writing about what it’s like to be an intern at the journal eLife!
Kumagai A, Ando R, Miyatake H, Greimel P, Kobayashi T, Hirabayashi Y, Shimogori T, Miyawaki A A Bilirubin-Inducible Fluorescent Protein from Eel Muscle. Cell 153: 1602-1611