Our summer research program is winding down, and preparation for the fall semester teaching is winding up. My student, Katrine Sjovold, and I have been trying to figure out what early melanocytes are doing — it’s a very simple and accessible system to observe cell motility, because the cells label themselves with melanin and we don’t need to do any of that persnickety cell injection stuff, or buy expensive dyes, or buy expensive cameras capable of detecting fluorescence (although we’ve tried a little of that here at the end of the summer, and I’ve been appropriately impressed that my research camera actually can see DiI fluorescence, even if it’s not designed for it).
Anyway, one of the things we’ve been doing is making time-lapse videos of melanocytes after they start making pigment and as they’re linking up and consolidating to form stripes. Here’s one example, a time-lapse where we take one image every 3 minutes over a day and an evening of growth.
You can see that we’re looking down on the dorsal side of the animal, in the region of the hindbrain (see the fourth ventricle, and the ears, deep and out of focus?). You may also notice that one of the melanocytes spontaneously decides to die and quickly breaks down into a few darkly pigmented blobs.
I’ve also uploaded a few other videos, but keep in mind these aren’t polished, perfect videos — these are bits and piece of our working data collection.