Day 8: Females > Males

I may have infused some sociological norms into today’s activity. Do boys really prefer blue? Or is it a social construct? Hmmm…

What does this have to do with day 8 of our fly genetics project? Well today students had the menial task of transferring their flies (and they will do it again Thursday before Finals are over) from their original culture tubes to new ones with fresh yeast and less dead flies (I equated it to a human living in a clear trash can with half-eaten food and dead things, after that they felt like it was necessary). Some students had only one fly left. Luckily, in all but one of them that fly was female. Why is that ok? Well it’s probably pregnant and will lay eggs. As far as we know, the males won’t lay eggs, so today females were better than males.

Students knocked flies down to the bottom of the original tube (by tapping the butt on the table) and then removing the cotton and turning the new one upside-down and placing it over the opening of the old one. Like so:

Old on bottom, new on top

Then of course, the Drosophila move upwards (gravitaxis anyone!?) towards the new vial. Then we turned the new one over and capped both with cotton. It then got a new label with the same genetic cross tag, student names, class period, and the NEW date.

However, we kept both vials as it’s possible our viable flies already laid eggs in the old culture tube and we don’t want to dispose of them. So now students get to take care of two tubes and by Thursday they will take the day 8 tube (today’s) and transfer it to a new tube. Then all the flies will take a 2 week hiatus and by the time we come back in January we will “hopefully” have a whole new business of flies. See you next year!