Yesterday we told you all about a recent study where a group of researchers identified the genes responsible for brain development in the womb. We pointed out, in our usual excitable way, that this discovery is the first step on the road to tinkering with those genes to produce mega-geniuses and mindless drones. The researchers made their discovery using a cool, high-speed method of identifying active genes called RNA interference (RNAi), which selectively suppresses gene activity. Here you can see the results of the RNAi process, which left a whole bunch of brain neurons in pretty bad shape . Above, the only untreated neuron is (A) - all the rest are RNAi mutants, whose weird shapes reveal what the suppressed genes do. Check out more mutated brains below.
Here is how the authors of the study describe what you're seeing in these images:
(A) Wild type (negative control). Wild type primary neurons in a mature culture show cell body clusters interconnected by well-fasciculated axon tracts. (B) Int6 transcription initiation factor knockdowns show extensive defasciculation. (C) Ran GTPase RNAi cultures have both excessive branching and defasciculation. (D) Huntingtin knockdowns show a moderate level of excessive branching. (E) Sec61α RNAi shows poor connectivity between cell clusters and highly branched, defasciculated neurons. (F) Diablo (cytoskeletal binding protein). Diablo knockdown leads to a primarily defasciculated phenotype. (G) CG12082 (novel gene) RNAi causes reduced connectivity between cell clusters, excessive branching and defasciculation. (H) Lpr2 LDL receptor knockdowns show excessive branching and defasciculation, yet with robust outgrowth. (I) Dopamine 2-like Receptor RNAi shows defasciculation.
A translation, as far as I am able to provide it, is that image (A) is an untreated bunch of neurons called a "wild type" (this is a term used for any non-modified or genetically engineered organism). The rest of the images are of neurons whose structure has been changed by the RNAi process. Don't worry - these are all fruitfly neurons. No human brains were harmed in the making of these cool images. Images via PLoS Genetics.