Who: I am a life-sciences explorer.
What: I surf nutrient-to-gene trails.
Where: My base camp is at the University of Geneva.
When: - gianpaolo.rando@unige.ch,

Iranian firefly with red-shift

There are some Iranian scientists that, instead of pursuing nuclear programs, pursue optical ways. Obviously I'm talking about reporter genes, what else? Tafreshi and colleagues, from Tarbiat Modares University in Tehran, recently described in the Biochemical Journal, a site-directed mutagenesis (His245Asn) of luciferase from Iranian firefly (Lampyris turkestanicus). According to the authors, the mutant luciferase holds a promising future for in vivo imaging, because this mutation retain an astonishing activity (76% of wt) compared to other red luciferases like firefly S284T (26% of wt). Red-shifted reporters (as mentioned for the fluorescent katushka some months ago) are very appealing for in vivo applications, because biological tissues and hemoglobin absorb preferentially green-yellow light. Red light is not absorbed, as shown by my hand in front of the lamp.

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Tafreshi, N., Sadeghizadeh, M., Emamzadeh, R., Ranjbar, B., Naderi-Manesh, H., & Hosseinkhani, S. (2008). Site-directed mutagenesis of firefly luciferase: implication of conserved residue(s) in bioluminescence emission spectra among firefly luciferases Biochemical Journal, 412 (1) DOI: 10.1042/BJ20070733