This morning, I learned how to fertilize sea urchin eggs. And then my lab partners and I made a movie of it (title pending). A movie, that is, of the egg and sperm doing their thang under a fancy microscope (Zeiss inverted microscope, using differential interference contrast, if you’re into knowing that kind of thing).
So, without further ado, I give you: Sea Urchin Fertilization 101
2. Turn the sea urchin upside down– which is mouth/butt side up– and inject a 0.5M solution of potassium chloride (KCl) into its body using a small sterile insulin syringe. The KCl relaxes the muscles around the gonads releasing their, ahem, contents (fun fact: KCl is one of the solutions used in lethal injections)
3. If female, you will see an orangish goop emerge from the animal’s topside. This goop = eggs
4. Turn upside down atop a beaker filled with filtered sea water to make an egg suspension. Be sure to label appropriately:
5. Now select another sea urchin and inject it. If orange goop comes out, repeat steps 3 through 5. If white goop comes out, congratulations: It’s A Boy!
6. Now, if it is a boy, grab a pipette and start transferring the sea urchin sperm to a eppendorft tube (or any tiny sterilized container would probably do):
7. Dilute the sperm in filter sea water using about 1-2 microliters per 1 mL of sea water.
8. Add a drop of diluted sperm into the egg suspension
9. Slap on a microscope, roll the camera and watch on the big screen:
I am told we will have our very own DVDs containing these movies at some point so, if WordPress allows for the file size, I will post some soon. Next up: playing with yeast and fertilizing sea squirts.