Some more pictures of the living octopuses!
Monday, July 7, 2014
Thursday, July 3, 2014
Live Octpuses
Footage of four, that's right, FOUR live octopuses, including two blue ringed octopuses.
Friday, June 27, 2014
June 26, 2014
So yesterday we did a dissection on three octopuses!
This is just a little tangent that I have to say right now. The plural of octopus really is octopuses. It would be octopi if the root was scientific Latin, but the word for octopus is actually Greek, so the correct way to make it plural is either octopuses or octoped.
ANYWAYS. Dr. Becky Williams brought in some frozen specimens that she had collected. The first blue ring we looked out was collected from Bali, and it turned out to be a pretty lame octopus. Dissecting cephalopods is a pretty tricky business in the first place, because they basically look like a giant ball of snot on the inside, but this one proved to be, for whatever reason, even trickier.
We were looking to take out the stellate ganglia, optic lobes, brachial hearts, (which are those blackish spots up at the top) and 'skeletal' muscle of the octopuses, because my experiments here in the lab are going to revolve around extracting the RNA from these tissues, and running it through some PCR (polymerase chain reactions) in order to get a library of all the genes those tissues contain, regarding the sodium gated voltage channel.
Why is that important you may ask? Well, obviously you didn't read my first post. Or I didn't explain it very well.
The real reason we're going through all these experiments and procedures is to shed some light on a pretty basic question- how can organisms with neurotoxin circulating about in all their tissues function? Obviously, there's some kind of trade off happening where the sodium channels, which control the function of neurons, have evolved to resist the toxin. But how? That is the real question. For many organisms, tetrodotoxin is highly lethal, shutting down all respiratory functions.
The poison starts by attacking the lungs and diaphragm. Within a few minutes, muscle paralysis begins to set in, eventually leading to full blown muscle petrification, basilisk style. This is where the complexity of TTX and sodium channels begins to set in though.
Cardiac tissue is going to be highly different than regular old muscle tissue, I mean, this crap works day and night from the day you were born until the day you die. It’s different. And whatever makes your heart able to pump continuously makes it resistant to TTX.
So there’s that. Even after asphyxiation is set in, the heart pumps on. The brain also turns out to be unscathed by tetrodotoxin, but that’s because of the blood-brain barrier.
And that’s why there is so much interest in this toxin. I mean, it’s terrible. But we’ve identified all kinds of animals that live, even thrive on this stuff. There are blue rings, newts in Oregon, Japanese puffer fish, Central American frogs, and Asian snakes that are all sequestering this poison and somehow remain untouched by its effects.
The real research, then, becomes studying how all of these creatures work genetically. By isolating the RNA, we can create amplified strands of DNA, which we can then sequence and compare.
It would be straightforward enough, BUT WAIT! PLOT TWIST!
Genes can create more than one protein. Yup, that’s right. If your biology teacher ever told you that RNA make DNA and DNA makes protein, they were only giving you half the story. (DNA actually forms polypeptides, and those link together to make proteins). But even before that stuff, Genes have what are called introns and exons. The exons are what actually get expressed, whereas the introns are kind of extra information that gets cut away. However, by getting rid of different introns at different locations, the cell’s diversity, even within just that gene multiplies exponentially. Thus, sequencing for the TTX resistant genes becomes much, much harder.
Now that was quite a tangent. Sorry. Back to what I was saying, about the tissues we’re taking out of the octopuses. So TTX is a neurotoxin, and one that is found to circulate pretty highly in the blood. That is why with our experiments, we’re looking at the stellate ganglion and optic lobe. The stellate ganglion function comparatively to the spinal cord in vertebrates. They relay information back to the brain, because they are actually a part of the central nervous system.
The cool part about octopuses is that they also have brachial ganglion, which sit at the base of each of the eight tentacles and independently control movement.
So we’re checking those out, for obvious reasons. We also wanted to take a look at the optic lobes, because octopuses have relatively extremely good eyesight, and because they connect directly to the brain.
That leaves the brachial hearts and the muscle tissue.
Octopuses are among the few mollusks that have closed circulatory systems, which may sound like an advantage, because to us it sounds like it would suck (I do puns sometimes) to have our blood pumped in and out from the ocean. But for most creatures it works, because octopuses have found the need to evolve three hearts along with those closed system. Two of them, the brachial hearts, lie just behind the gills and collect the oxygen the gills get. The third heart actually does the pumping and cardiovascular jazz. It’s the systemic heart. We never really found the systemic heart, though Becky believes we got something that may have been it.
And lastly, we collected some muscle tissue. As I said, muscle paralysis happens fairly quickly, so the sodium channels located in the muscles are TTX sensitive.
Seeing as how this was my first ever dissection, Becky and Shana took the reins more for the blue rings. As you can see, these guys are tiny! And with the first one, nothing was very clear. The hearts were easy to get out, but not much else was. I got to do the next one though.
It was purple, it was bigger than the others, and it was from Florida. That’s about all I can tell you about it, except the scientific name- which was O. mercatorus.
The hearts in that guy were easy enough to find, but the real excitement was actually the stellate ganglion- they were HUGE. I wish I had a picture, but I mean, we could easily see them without any microscopes or anything like that. Its exciting stuff, okay? The nervous system of most anything else besides cephalopods is too small to see. And, bragging time, I was chosen to take those out of Mr. Mercatorus. The dissection went good, and then we started work on the last blue ringed octopus, this time from the Philippines. Becky says the geographical difference also means speciation occurred, but nobody has done enough taxonomy to really say anything about it.
Whatever the difference was, this guys was much easier to look at. We were able to find the stellate ganglion waaaaaay easier, it took like a second, and from there on out it was smooth sailing.
Not going to lie, the past two days have been the most exciting so far. There was all the work I just mentioned yesterday, and then today I got to run a PCR on some ambystoma (salamander) cDNA. That whole process is really not that interesting, so I’ll just say that the first time I screwed it up, but then Charles fixed it and now we’re on track to get some salamander sequencing. But I learned a very valuable lesson, dealing with microliters and nanograms-
Don’t believe your eyes. Listen to what your heart tells you.
So yesterday we did a dissection on three octopuses!
This is just a little tangent that I have to say right now. The plural of octopus really is octopuses. It would be octopi if the root was scientific Latin, but the word for octopus is actually Greek, so the correct way to make it plural is either octopuses or octoped.
ANYWAYS. Dr. Becky Williams brought in some frozen specimens that she had collected. The first blue ring we looked out was collected from Bali, and it turned out to be a pretty lame octopus. Dissecting cephalopods is a pretty tricky business in the first place, because they basically look like a giant ball of snot on the inside, but this one proved to be, for whatever reason, even trickier.
We were looking to take out the stellate ganglia, optic lobes, brachial hearts, (which are those blackish spots up at the top) and 'skeletal' muscle of the octopuses, because my experiments here in the lab are going to revolve around extracting the RNA from these tissues, and running it through some PCR (polymerase chain reactions) in order to get a library of all the genes those tissues contain, regarding the sodium gated voltage channel.
Why is that important you may ask? Well, obviously you didn't read my first post. Or I didn't explain it very well.
The real reason we're going through all these experiments and procedures is to shed some light on a pretty basic question- how can organisms with neurotoxin circulating about in all their tissues function? Obviously, there's some kind of trade off happening where the sodium channels, which control the function of neurons, have evolved to resist the toxin. But how? That is the real question. For many organisms, tetrodotoxin is highly lethal, shutting down all respiratory functions.
The poison starts by attacking the lungs and diaphragm. Within a few minutes, muscle paralysis begins to set in, eventually leading to full blown muscle petrification, basilisk style. This is where the complexity of TTX and sodium channels begins to set in though.
Cardiac tissue is going to be highly different than regular old muscle tissue, I mean, this crap works day and night from the day you were born until the day you die. It’s different. And whatever makes your heart able to pump continuously makes it resistant to TTX.
So there’s that. Even after asphyxiation is set in, the heart pumps on. The brain also turns out to be unscathed by tetrodotoxin, but that’s because of the blood-brain barrier.
And that’s why there is so much interest in this toxin. I mean, it’s terrible. But we’ve identified all kinds of animals that live, even thrive on this stuff. There are blue rings, newts in Oregon, Japanese puffer fish, Central American frogs, and Asian snakes that are all sequestering this poison and somehow remain untouched by its effects.
The real research, then, becomes studying how all of these creatures work genetically. By isolating the RNA, we can create amplified strands of DNA, which we can then sequence and compare.
It would be straightforward enough, BUT WAIT! PLOT TWIST!
Genes can create more than one protein. Yup, that’s right. If your biology teacher ever told you that RNA make DNA and DNA makes protein, they were only giving you half the story. (DNA actually forms polypeptides, and those link together to make proteins). But even before that stuff, Genes have what are called introns and exons. The exons are what actually get expressed, whereas the introns are kind of extra information that gets cut away. However, by getting rid of different introns at different locations, the cell’s diversity, even within just that gene multiplies exponentially. Thus, sequencing for the TTX resistant genes becomes much, much harder.
Now that was quite a tangent. Sorry. Back to what I was saying, about the tissues we’re taking out of the octopuses. So TTX is a neurotoxin, and one that is found to circulate pretty highly in the blood. That is why with our experiments, we’re looking at the stellate ganglion and optic lobe. The stellate ganglion function comparatively to the spinal cord in vertebrates. They relay information back to the brain, because they are actually a part of the central nervous system.
The cool part about octopuses is that they also have brachial ganglion, which sit at the base of each of the eight tentacles and independently control movement.
So we’re checking those out, for obvious reasons. We also wanted to take a look at the optic lobes, because octopuses have relatively extremely good eyesight, and because they connect directly to the brain.
That leaves the brachial hearts and the muscle tissue.
Octopuses are among the few mollusks that have closed circulatory systems, which may sound like an advantage, because to us it sounds like it would suck (I do puns sometimes) to have our blood pumped in and out from the ocean. But for most creatures it works, because octopuses have found the need to evolve three hearts along with those closed system. Two of them, the brachial hearts, lie just behind the gills and collect the oxygen the gills get. The third heart actually does the pumping and cardiovascular jazz. It’s the systemic heart. We never really found the systemic heart, though Becky believes we got something that may have been it.
And lastly, we collected some muscle tissue. As I said, muscle paralysis happens fairly quickly, so the sodium channels located in the muscles are TTX sensitive.
Seeing as how this was my first ever dissection, Becky and Shana took the reins more for the blue rings. As you can see, these guys are tiny! And with the first one, nothing was very clear. The hearts were easy to get out, but not much else was. I got to do the next one though.
It was purple, it was bigger than the others, and it was from Florida. That’s about all I can tell you about it, except the scientific name- which was O. mercatorus.
The hearts in that guy were easy enough to find, but the real excitement was actually the stellate ganglion- they were HUGE. I wish I had a picture, but I mean, we could easily see them without any microscopes or anything like that. Its exciting stuff, okay? The nervous system of most anything else besides cephalopods is too small to see. And, bragging time, I was chosen to take those out of Mr. Mercatorus. The dissection went good, and then we started work on the last blue ringed octopus, this time from the Philippines. Becky says the geographical difference also means speciation occurred, but nobody has done enough taxonomy to really say anything about it.
Whatever the difference was, this guys was much easier to look at. We were able to find the stellate ganglion waaaaaay easier, it took like a second, and from there on out it was smooth sailing.
Not going to lie, the past two days have been the most exciting so far. There was all the work I just mentioned yesterday, and then today I got to run a PCR on some ambystoma (salamander) cDNA. That whole process is really not that interesting, so I’ll just say that the first time I screwed it up, but then Charles fixed it and now we’re on track to get some salamander sequencing. But I learned a very valuable lesson, dealing with microliters and nanograms-
Don’t believe your eyes. Listen to what your heart tells you.
Octopus Dissection
And this is my second video, Showing you where I actually work and a short description of my recent octopus dissection.
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