Genetics is complicated: mouse edition

Genetics is complicated. I have taken courses to this effect; I have taught the concept in Introductory Biology. Mendel’s peas with their neat logical Punnett squares were a lucky rarity—each trait governed by just one gene, each of those genes on a separate chromosome. The genetic basis of the vast majority of traits is far more complex. If the genes involved aren’t physically linked (called “linkage disequilibrium”) then they are pleiotropic (influencing many different traits at once), or epistatic (modified by other genes), or simply so subtle that their effects disappear in the noise of environmentally-caused trait variation. Relating traits to genes is hard.

I know this; I understand it; but until recently, I had never actually seen it. Then my pet mice decided to give me an object lesson in genetics.

What happens when you think you have all female mice, but you actually have mostly females and one male?

This happens. (Incidentally, doesn't this look like a mouse version of the Canadian flag?)

This happens.
(Unrelatedly: doesn’t this look like a mouse version of the Canadian flag?)

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Another freelance science mouse

A few months ago, my labmates who study chipmunks enlisted the help of one of my pet mice to test-run a chipmunk-monitoring device that they are hoping to use in the field this summer. That went well, and now they’re calling on another one of my mice for a simpler test: to see how long the glue they’re planning to use will keep their device attached to rodent fur. They want glue that will stay attached long enough for them to get good data, but not so long that the monitor becomes a permanent part of a chipmunk’s life.

Since chipmunks spend a lot of time in burrows, we chose my most burrow-loving mouse, who likes to spend all of his time hiding underneath things. He was not pleased to be forced out into the open.

Porter with the test chip glued to his back

Porter with the test chip glued to his fur

So far he hasn’t seemed to care a bit about the chip. However, he is quite annoyed that I now dig him up daily to check whether it is still attached. He’s not really a people mouse.

PLEASE just leave me alone.

PLEASE just leave me alone.

Much better.

Much better.