Ah, urchins. I study these and still I learned quite a bit. We did what I consider more cell biology than developmental biology... but still I guess cells must divide to develop. I was amazed at what a cheap antibody from the Hybridoma bank and DAPI could accomplish. It was more beautiful than anything they showed me in college and much more informative than the cartoon drawings of chromosomes moving around. Admittedly, the class lost quite a few embryos in the washing, but I was intrigued to know that you didn't need to remove the fertilization envelope to stain. Interesting...
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| Three spindles (green) due to the maternal contribution and that of 2 sperm... polyspermy |
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We got a brief introduction to frogs as Steve Black, a special guest instructor, started preparations for "Frog Day!" The frogs looked very very squirmy - poor patients for injecting hormones.
And then it was time to cut more. This time we zoomed up the evolutionary ladder to chickens. I was hesitant about chickens. The last time I 'explored' a chick embryo was in third grade. I didn't like my third grade teacher to begin with (I was vehemently opposed to wearing a sign for weeks that said ILAC - I am Lovable and Capable) and after that lesson I refused to eat eggs for 2 years. My mother thanks you. Excuse my digression. This lesson was FAR better... and proved that my third grade teacher was WRONG.
The embryo is NOT the white things on the side. It is the white swirl in the middle or if its old enough and has made blood it is in the center of the red area (see picture above). By three days you can see the heart beat and move the blood around. Very cool.
It was the heart that we went after for our chick experiment. First we had to remove the embryo from the yolk and perform the surgery - a simple nick to the region of the future heart. This nick causes the region to separate and form two twin hearts as the chick grows in culture.
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| 3 somite chick at initial isolation in culture and post-surgery. |
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| 48 hours later the chick has grown in culture and developed twin hearts. Both hearts were observed to beat. |
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