research June 28, 2014

Fugu Fish Friday

By Ariel O'Neill

Happy Fugu Fish Friday!

Modified from https://www.factzoo.com/sites/all/img/fish/fugu.jpg Quick Fugu Facts: - The Fugu Genome Project was finished after the Human Genome Project, but was still only the second project to sequence a vertebrate genome and release it to the public. - The genome of*Takifugu rubripes*, one species of fugu fish, is available here. - The project was facilitated by the fact that the fugu genome is about 1/10 the size of the human genome. (Source) - People eat fugu fish, even though the fish contain tetrodotoxin, which can cause a morbid and horrible death if the fish has not been properly prepared. - Current research indicates the presence of tetrodotoxin in the fugu fish may be a result of biomagnification. Bacteria producing the toxin may be below fugu fish in the food chain. - Fugu fish are, unsurprisingly, bad swimmers. They aren't exactly hydrodynamic. - Instead of fleeing from predators, they puff up to scare them away. This behavior is why fugu fish are also called pufferfish or blowfish. Today I practiced setting up agarose gel and running gel electrophoresis, but I promised in my last post that I would say a few words about setting up an embryo culture this time. Why it's important: It's hard to study the development of sea urchin embryos without sea urchin embryos. How you do it: - Get a hold of a male urchin and a female sea urchin. (Sound familiar?) This is tough for two reasons. First, sea urchins are very good at holding on to the side of an aquarium tank. Second, there is no way to tell the determine sex by looking at the animals. The only way to tell is by looking at the gametes. Sea urchin eggs are yellow and the sperm is white. How do you get the gametes? - Shake the sea urchin in your hand like you are trying to explode a can of soda. The stress induces the sea urchin to release the sperm or eggs. We collect the eggs in a beaker and use a pipette to collect the sperm. - Mix the eggs and sperm in some filtered sea water. Too much sperm can lead to polyspermy, not enough sperm leads to low fertilization rates. Too many embryos in too little sea water delays or distorts development. - Make the embryos happy. There's a motor-powered spinner we put in the water to simulate ocean waves. - Wait until the desired timepoint. Oh, and sea urchins develop well at 15 °C, which means that rooms with animals or embryos tend to be much cooler than it is outside the lab in sunny Pasadena. Here's one more fugu fish for luck!