Wisconsin Public Television	University Place		A New Hormone-Receptor System in Plant		Michael Sussman		3/5/14	UP992  cc >> Welcome everyone to Wednesday Nite at the Lab. I'm Tom Zinnen. I work here at the UW-Madison Biotechnology Center. I also work for UW-Extension, Cooperative Extension. On behalf of those folks and our other organizers, Wisconsin Public Television, Wisconsin Alumni Association and the UW-Madison Science Alliance, thanks again for coming to Wednesday Nite at the Lab. We do this every Wednesday night, 50 times a year. Tonight it's my pleasure to introduce to you my boss, Mike Sussman. He's a professor of biochemistry. He's a director of the Biotechnology Center here. He grew up in Queens. 

He went to school at Bucknell, got his undergraduate degree there. He got his PhD at Michigan State. He did a post-doc at Yale, then came to the UW-Madison. He's been the director of the Biotech Center since 1996, I believe. >> I think '89. No, no, '96. '96, right. >> 1996, didn't I just say that? >> Sorry. >> That's all right. And just about five weeks ago he and his group had a major paper published in the journal Science on this plant hormone receptor system. 

Mike is going to talk with us about that and the saga of discovering that over the last three years, and some of the other projects that he's hoping to work on. He goes to the extremes. He looks at the weird things in nature and says, let's figure out how those weird things work, and see how we can put them to work. Please join me in welcoming Mike Sussman back to Wednesday Nite at the Lab. [applause]  >> Thank you very much. Is this okay? Can you hear me okay? Good, good. Well, this is wonderful. I started off this day at Verona High School. I gave a talk to biotechnology class there. I'm very pleased to be able to communicate some of the results that we recently published in a high profile journal. 

It's about a four year project. Plant growth is a little dry when I get to the details about how these proteins-- So this talk is going to be a little more general. I also love to give informal talks. I don't want to just talk, I want to communicate. I want to interact. Please don't hesitate to stop me if anything is confusing, or if you have any questions or insights that my slides provide. And there'll be plenty of time afterwards as well. Although mainly, Tom asked me to talk about this protein that controls the size of plants cells. It's a protein and a hormone that in plants kind of acts like the epidermal growth factor and epidermal growth factor receptor in humans. It controls development and how big cells, and how big we are, actually. 

It does much-- The analogus protein which we discovered does that in plants. But let's talk more generally about DNA, protein. Because fundamentally I am a genomecist, which means I deal with all 30,000 genes that are present in our nucleus. It turns out plants also have 30,000 genes. Many plants actually have more genes. Those 30,000 genes make 30,000 proteins. Those proteins do all the heavy lifting in the cell. They catalyze the formation and breakdown of amino acids and lipids and all the sugars and everything. We call that the-- The DNA is the genome, the RNA is the transcriptome, the protein is the protiome and the small molecule collection is the metabolome. We actually not only are using our DNA sequences to figure out each and every one of those proteins and genes, we're using the mass spectrometers to analyze every molecule in our body. 

We're actually cataloging each and every molecule. Then we're using that information in important things like biomarkers. My lab is trying to replace colonoscopies with a blood test. For those of you who are over 50, you understand how useful that would be, how much more pleasant a blood test would be. We're actually making fairly good progress. This is all based on these extremely expensive instruments called mass spectrometers. A lot of the work I'm telling you will be about our use of these mass spectrometers. They're right upstairs. In fact, afterwards, if you'd like to visit my lab I'll show you them. We also have the next generation DNA sequences. 

These are million dollar machines. We have three of them right on this floor. We're the only one on campus. We sequence DNA for everyone on campus. This university is has three to four hundred million dollars per year NAH money. I'd say over half of all those biologists sequence DNA at some point, they come here to do it. We've also recently been pushing to get CLIA-certified, which means we will now be sequencing human DNA that will be used for diagnosis and, hopefully, treatment. This is a new area of that. I won't be speaking about it, but hopefully Tom either already has somebody speaking about it or will have in the near future. For my talk, it's going to be a fairly molecular talk, but I'll try to put in a perspective. 

Just so you know, DNA is ultimately what controls what types of protein we have and where and when their made. This is the central dogma, DNA makes the RNA makes the protein. The 'omes,' and this is my life. I know these words are not common, but they are in my world. All the DNA is genome, the proteome and the metabolome. And that's basically us, these three are it. This slide shows about 10,000 spots. Each spot is a different DNA gene in your body. You can't see the colors but they're either red, yellow or green. For example, with this kind of a-- It's called a DNA chip. 

We can take a normal liver and a cancerous liver and we can ask, which of the 30,000 genes is being mis-expressed in the cancer liver. And we can find, out of the 30,000, about 200 to 300. Once we know which 200 to 300 they are we can then actually target drugs specifically to those 200 to 300 and try to kill that cancer. That's precisely what the biotech revolution is all about. Finding out a small number of genes involved in that diseased state and then either using genetics or chemistry, drugs, to treat that disease. This slide shows a beating muscle tissue. Do you see that? About every five seconds? Now amazingly, this slide came from Jamie Thompson. He had a Petri plate of human embryonic stem cells. These are pluripotent, they're not differentiated. But on their own, over a period of time, he noticed they formed red dots. 

When he put those red dots on the microscope he saw this. Now the cells are only, like, that's one cell there. What was happening was these pluripotent stem cells were starting to form cardiac myocytes. They actually were forming heart tissue. These heart tissue cells were beating together. They were forming what's called gap junctions and they were learning to beat like a human heart. This is now commonplace, growing a human tissue from these pluripotent stem cells to try to replace diseased tissue. This was new ten years ago, and now it's commonplace. Basically, it comes down to that DNA chip I showed you, we now know a handful of genes that will take a pluripotent stem cell and push it towards a cardiac myocyte. It may only be six genes that you need to upregulate to get that process going. 

Biology is becoming an engineering problem. Now that we know the identity of the 30,000 genes it's now an engineering problem like a circuitry. Which parts of the circuit do you tweak to get the final result that you want? That's true in plants too. A lot of my work is aimed at discovering which genes in a plant are critical for how a plant grows. One of the things that, worldwide, many of us are interested in is drought. The population is getting very high and most of our good land is being used up. Now we have to grow plants on areas that are not very wet. We're now engineering plants that can grow at very low water levels. We're not only using genetic engineering, we're also using classical breeding and a combination of both. I won't get into the ethical issues of genetically modified organisms verses breeding verses doing nothing. 

They're incredibly important, but I don't have time to do both the science and that. But I would be happy to come here again or talk with you in private. Those are very, very complicated. If I can just throw the gauntlet out now, I will tell you, we have the power to cure diseases, or at least treat them, with genetics. But we've all kind of drawn the line that we're not going to alter the human germ line. In other words, we're not going to alter the sperm and the egg. That would be passed on permanently. But I would ask you that, if it becomes possible to cure disease permanently and you don't do it, is that ethically right? In other words-- The problem though with genetically engineering a germ line, it's called eugenics. You might argue, we're not smart enough to really do that properly, or do that ethically. I tend to agree with that. 

However, there are countries out there that are looking out there that are looking at this. I've heard rumors that, for example, in China they're looking for intelligence genes. We can now plan an experiment and try to find genes that really produce high intelligence. Then you can imagine using that information to, either alter the genes in a sperm or an egg, or select for those fetuses that can do that. These are things that are technically possible. They're ethically very questionable. They may be going on, we don't know. These are things that you all should be thinking about, because these decisions shouldn't be made just by scientists. They have to be made by us collectively, as a whole. I view my job as trying to give you the technical information that you need to understand what can and can't be done, and help guide what should be done. 

 Basically, I already mentioned this that biology is becoming a very engineering, in my opinion. It's very interesting. Engineers are used to thinking of systems as a whole, and biologists are beginning to do this. For the first time we know have all 30,000 genes in from of us. But engineers have been thinking like this already. Many of the engineering departments are becoming biology. The department of chemical engineering is now called the department of biological and chemical engineering. I've often wondered whether the engineers are going to become biologists faster than the biologists are going to become engineers. I'm beginning to think that might happen. Biology is still extremely complicated. 

I know it's only 30,000 genes, but think about 30,000 things interacting with each other in all possible combinations. I think that's 30,000 factorial. It's a huge number. To give you an idea of the power of DNA, each of us has three billion beads in a string, I call it. We have four bases, A, T, C, G. Think of a string of beads, three billion long. Each bead can have four colors. It's the sequence of those colors that determines you and me. Each of us has 1,000 beads in a row, and 999 of them are identical. There's actually very few differences amongst us but those are every important differences. 

But in theory, there are four to the three billionth ways of creating a human being, four to the three billionth power. More than there are atoms in the universe. Think about all the species of life on Earth with all of that DNA. How long has evolution occurred? The universe is 14 billion years old, the earth is about four billion years old. Life began very early, probably about 3.8 billion years ago. All of the cells on earth have been evolving for 3.8 billion years. There's a lot of niches, a lot of ecosystems, a lot of cells. The opportunity to explore what I call DNA space is enormous, and that's what nature's been doing using four to the three billionth power to select for properties that allow an organism to thrive in an environment that other organisms won't. That's called evolution. I'm going to give you some really cool examples of evolution. 

This is a different talk so I won't-- Don't worry about this. I do want to say one thing. Many people don't realize how much of a jewel UW is. I think we're number five in the county in terms of total dollars brought in for non-military uses. Here's another thing, if when you look at our peers in term of members of the National Academy of Science, we're like number ten. We're in the 40's. All the other Midwestern universities and our peers that are at twelve, ten, eight, nine. The only ones that are better than us are kind of elite universities. So for a Midwestern university we're incredibly successful. Okay, now for the meat of my talk. 

Nature's gifts. Remember I said there's 3.8 billion years of evolution on the Earth, which is a pretty big environment. You've got everything from thermal vents in the ocean to the Amazon to the top of Tibet, all these environments with different temperatures and oxygen levels and different amounts of light. Nature has used all those years to produce some really strange creatures that I like to work on. I consider plants some of the most strange. Even though they can't move, they actually are-- They're doing a Zen-like thing. Their biochemistry is the most complex, their metabolome. In fact, half of the drugs that we take come from a plant. They are little chemical factories. Basically, what they're doing is they've develop ways to encourage you to eat them. 

Then you die and you fall at their feet, and you nourish their babies. Or you propagate their seeds by eating apples, or growing their cannabis, whatever. They have developed ways to manipulate us. They're really smart. My favorite though is the bamboo growing through concrete. They use -- which is-- I'll get into it later, but it's an incredibly, basically filling a dialysis bag with a very high potassium concentration and water floods in. By having this cellulosic wall, all that water is pushing on the wall. The wall can't move, and you wind up with enormous pressure, which can be pointing and then move-- It can actually break through concrete. Another gift is the 13 line squirrel. Do any of you know this? Okay, you've heard Hanna -- maybe, give a talk. 

These creatures are living right out there. For three months out of the year in the winter they bring their body temperature down to four degrees centigrade. That is how their survive through the winter. That's extremely important. We know now that if you have an accident and you start bleeding, a good way to maintain your life is to bring your temperature down. We need to know how an animal can live at four degrees for three months. If we can learn how it does that and we can apply that in the hospital there are some huge benefits. My daughter was involved in catching these little critters at the golf course and she can tell you how she did that. They don't like to be caught but it can be done. Another one is the sloth. 

This is a friend of mine, Chris --, who's now at the University of Costa Rica. If any of you want to spend a month researching with him let me know. He is in charge of a program of bringing students from the US down there. The sloths really like to live in the chocolate farms. They have these metal cables that help them collect the chocolate. He's actually a very strong environmentalist and he's also helping. The women in this chocolate farms have to sell their chocolate very cheap to our chocolate companies. They don't get a lot of the money. He's taught them actually how to make their own chocolate. He come to America with a couple of hundred bars and he sells them for a dollar a piece, and he brings the money back to the women. 

He's really an interesting fellow. His life-long passion is the study of the sloth. The sloth is like a plant in that it moves real slowly and that's how it evades getting eaten. Tigers are looking for movement. The sloth is unique because it's muscles are very interesting and different then ours. A sloth will continually move for hours and days but not get very far. For example, I think the fastest sloth on record went a mile in a month, which translates into a yard in an hour. I would challenge any of you to continually move for an hour and only go a yard. You can't do it, actually. Their muscles allow them to move almost like they're taking LSD. 

They look like this. [laughter] And there are a fantastic and interesting environment. There's a professor here who just discovered they have an algae that they eat and it lives in their fur. And there's a moth involved in the algae. There's some very interesting questions that the sloth biology is helping us answer. I find them fascinating. We've sequenced their genome, but it's funny, sequencing a genome isn't enough to give you what you need to answer some biological questions. It's a good start. It gives you the identity of the molecules, but how those molecules are interacting and achieving the outcome is a completely other story. That's really hard. 

Then finally, this is-- Does anybody know what this is? Yeah? Okay, excellent. This is electrophorus electricus. It's the strong-voltage electric eel from South America. I've got one in a tank upstairs. We recently completed sequencing its genome. It and about 800 other electric fish have a cell that no other organism has. It's called an electrocyte. It's much like a myocyte, a muscle cell, except it doesn't contact. And instead of putting all the chemical energy of ATP into contracting, it puts all that energy into shooting a voltage out. They're extremely unique, the electric fish, in that they shoot this voltage anywhere from one to 20 feet away. 

Now there's about 800 species of weak electric fish that use this voltage for communicating and electrolocating. These fish use electricity like bats using radar. They bounce electricity off the surface of the floor of the river. They also communicate like birds singing. To find their mates they have electric organ discharges of various frequencies and that's how they find their mates. But out of the 800 species of weak electric fish there's only six species of strong-voltage electric fish. One of them is that guy. They've taken these electrocytes and they've stacked them into like six foot long cattle prods. You have these electrocytes that are stacked like batteries in a flashlight. Even though each electrocyte can only produce maybe 100 millivolts, when you put 1,000 of them together you have 100 volts. 

When you have a six foot eel you actually have 600 volts. I'm actually going to show you a fairly disturbing video that displays the power of an electric eel.  But let's get back to plants. Okay. Yeah. [inaudible] The power, yeah. By the way, I've lost a bit of my hearing, so I appreciate your yelling out. The power is enough-- I'm going to show you an eel that kills an alligator with that power. You can tell for yourself, if you want touch the eel upstairs, you'll feel it. It's kind of like putting your finger in a thing. 

It's 100 volts for every-- The amperage goes up with length. An eight foot eel is basically the dominant predator in a river. They will kill anything they want. But it's no enough power to run your car. Definitely enough power to charge your cell phone. Much like Jamie has figured out how to take stem cells to make muscle cells, I'm going to show you results that has pointed us to about ten transcription factors, regulatory proteins, that we believe will convert a muscle cell to an electrocyte. We believe we can make electric organs in the lab and in organisms that don't normally have them, a mouse, a dog, a cow. A cow's got a lot of extra muscle and if you only convert 10% of a cow into electric organ that could actually generate a sufficient amount of power. It's a crazy idea, I know. My technician hates when I talk about it because she has cows. 

She's not a very big person. She already has trouble getting them to do what she wants them. If they can electrocute her she'll be really upset. But I'm telling you, we are conquering differentiation. It's no longer a question of what can we do, it's what should we do. Think about that. Let's go back to plants. Plants and sloths are immobile but they've conquered their environment in really kind of a cool way. I'm going to show you a time-lapse video. Go. 

There we go. Many of you have beans with these vines. This is called circumrotation. It's extremely well controlled. They're searching for something to grab on to. They grab it, and now they're going to keep going. Now we have mechanosensing calcium channels. These are proteins in our membranes that tell us when we're touching something. Plants have the same proteins. That's what's amazing about nature. 

The same proteins are used by us and by a plant, but we're much different things. Now we took these long cells called nerves and we -- them so that an action potential could move six feet in a micro second from a brain to a muscle. Plants have action potentials. When you touch a leaf you are actually generating an action potential that cells depolarize it. It only moves about this far. We're not sure what it's function is. If any of you have seem Mimosa Pudica, the touch sensitive plant, or a Venus flytrap. There it has an obvious function. That again is a mechanosensing calcium channel much like the one in our skin or the ones in our ears, the hair follicles that sense the bending. In the Venus flytrap when you touch those hairs you ultimately generate an action potential that causes the cells in the -- to loose the potassium and -- the thing closes. 

It's a millisecond to a second, not a micro second, but it's the same basic principle as a nerve/muscle system. That's why I have a problem understanding where you draw lines in terms of what do you kill. If you define life as action potentials in a brain, plants have action potentials. I mean they're not thinking in the same way we are, but they are thinking in a way. They're knowing when you're touching them and they're responding to that. I'll show you another one here. This is kind of cool. This is now germination of a seed, I think it's a sunflower seed. This is over a period of a few days. See this motion? Again, they are exploring space. 

They can't walk so they're using this motion to explore their space. They're looking for maximum sunlight, trying not to be shaded by their neighbors. They're emitting gaseous molecules that tell them these things bounce off. They're actually communication with each other. They know when it's very dense by some gaseous molecules. There's a lot of chemicals that their roots are giving off. There are microbes in the soil that are giving off chemicals that are telling the plant, hey, there's a friendly bacteria here. They're called mycorrhizel fungi, and if I associate with that fungus it's going to give me phosphate that I normally can't get. And the fungus is going to love the plant because it's going to get carbon it doesn't normally get. Yeah. 

[inaudible] I need someone to-- I can't hear that. >> What what frequency are plants doing that? >> Oh, okay, I got ya. Um, yeah. Probably in the matter of hours back and forth. It's actually going like this. I'm glad you raised that, because the mechanism of that bending are unequal elongation rates of cells on one side of the stem verses the other that we believe is controlled in part by this hormone we found, this hormone called RALF. It's a peptide hormone. Another hormone known as -- also controls elongation. If this side of the stem is growing faster than that side it's going to bend that way. Phototropus is the mechanism. 

Circumrotation which is this very interesting movement like that is still poorly understood. It obviously involved gravity, but there's an inborn mechanism to use gravity and do this kind of a motion. I'm not an expert on this. There are people on campus who are. I think Simon -- actually over in botany studies this quite a bit with NASA. But I do want to tell you a little more about plants and basic biology. There's really only two places in a plant that there's any real cell division going on. That's at the very tip of the root and the very tip of the stem. This is the tip of the stem. Normally you can't see it. 

It's buried inside the leaves, It's called the shoot --, or SAM. It's really the only part of the stem that you've got to be careful about. If you snip that off nothing more grows. Let me show you a better picture. At the very tip, it's about 100 cells and their stem cells. They're pluripotent stem cells in the stem. There are stem cells in the root if you use the word stem in the sense of undifferentiated. [laughing] The cell division is occurring here and the cell division is occurring here. Most of the remaining growth is elongation and differentiation. After the cells divide at the shoot they will then differentiate and form leaves. 

Those are the lateral leaves. At some point during the right photo-period, they sense the season, and instead of forming leaves they'll form a flower. That's a major transition. It's the only major transition. And actually on this campus one of the professors discovered which genes control that. There's one regular master gene that controls when a plant flowers. This is the layer of cells. I just want to show you, these are the nuclei in a tip of a root. You can see how densely packed they are here. This is where all the cell division is occurring, and the cells are small. 

It will keep growing this way and these cells no longer divide but they get longer and longer and longer and longer and longer, and they start differentiating. They form the xylem and the phloem, you that stuff that gets stuck in your teeth in the celery that allows the water and the sugars to move. That's what they're forming. They're also forming root hairs. Again, it's just mostly elongation that's going on. The only place that's cell division is that very tip of the root and the very tip of the stem. This is a slide I just pulled up today of an individual who had a deficiency of human growth hormone with her friend. When she was treated with this she then became normal height over a period of years. This human growth hormone and the human growth hormone receptor is very similar to the hormone and the receptor we found in plants that controls the size of plant cells. And I'm just telling you, the universality of life on Earth is just incredible. 

They look different. I know they do. I mean, a plant looks different than a cow, right? But when you get at the molecular level it's eerie how similar we are. We're just using these genes in different ways to survive and thrive in the environment that we evolved in. This is the paper that we recently published. We described a new peptide hormone in plants and a receptor, protein kinaes, that regulates cell expansion. We're going to go through a few slides that will give you an idea about it. There is a fundamental difference between plant and animal cells at the plasma membrane. Much of my work involves this. Plasma membrane is the membrane that surrounds the cell that some people think may be more important than DNA for the beginning of life. 

In other words, the membrane is where all these transport proteins are that allow all the rich molecules inside the cell to stay inside the cell and not de defused and diluted. You could argue that the first cell was a way of concentrating things, not necessarily DNA. Let me just show you. In animals there's a sodium pump that uses ATP to pump sodium out. That sodium gradient, where you have less sodium here and more sodium there, is then used to drive glucose and amino acids in or out of the cell. So sodium is really our universal power. We require sodium and if we get low on sodium you die. If you get low on sodium you walk over to the ocean and you get a little bit of salt. We need it. Plants completely don't use sodium. 

They thrive in a complete absence of sodium. Instead of using sodium to power this plasma membrane transporter, they're using another cation, a proton. Why are they using a proton? Well, they can't move to salt, so they're relying on the one cation that will always be around. There's always a proton. It may be a very long concentration, but it's there. It's like this fundamental thing that make a lot of sense to me. They're using a proton with the same type of enzyme, instead of a sodium ion, and this proton is being used to also move glucose, amino acids, and this potassium. Plants have an enormous amount of potassium. Like pot ash, when you burn wood all of that stuff that doesn't-- that ash is mostly potassium. Potassium is what allows a plant to be 90% water. 

Plants accumulate an enormous amount of potassium. It's like a dialysis bag with a lot of salt inside of it. The water comes in and the bag expands. That's like fundamental to how a plant survives, this water flux in and out in response to potassium. When that plant is bending, or Mimosa Pudica, a lot of it is potassium that's moving in or out and those cells are gaining or losing water. That's basically how a plant moves, through --. We also have --. If you're not drinking enough, and doctors use this with babies, if a baby is dehydrated you push down and if it doesn't bounce up quickly enough you know it's dehydrated. But the amazing thing about plants is this: Anyone one here kills a plant by forgetting to water it? Okay, I want to make sure you're not liars. We've all done it, right? Okay, I've done that. 

Now, there's something called the permanent wilting point which is about 70% water. We're about 90% water, plants are about 90% water. When you forget to water it and it gets down to about 80% a plant can handle it. But when you get down to 70% it's in trouble, and when it dips below 70% it dies. That's a vegetative plant, the green plant. However, a seed is a living plant cell. Seed have living plant cells but they are like a sloth. They are very slow metabolizing, they last 100 years, but they're alive. They're 12% water. So we know a plant cell can survive at 12% water. 

It just doesn't do it in its vegetative phase. If we can figure out how a seed allows those cells to survive and use that information in the corn plant that's growing in August we can allow a corn plant to go less than 70% water and still survive. That's kind of where a lot of money is going into research right now. There are a few odd plants out there that have taken this trick and used it. There's something called the Resurrection Plant in Arizona. You're shaking your head, have you seen it? That plant actually can get down to about 14% water without dying. It looks like it's shriveled up, it looks like an herb. If you add water it comes right back to life. It never dies, even at 12% water. Again, we've sequenced its genome, but the genome doesn't tell us the secrets that that plant uses. 

It's very complicated and we're still trying to sort it out. If it was easy it would be don't this year or next year. It's probably going to take about 20 years to figure that one out. My lab started asking questions about five years ago about, are there peptide hormones in plants that act like in humans? When we looked at the plant sequences we noticed about 450 proteins that look like receptors, like animal receptor kinaeses. Out of those 450 receptor kinaeses there were three that looked like they were binding peptide hormones. Only three. Then we asked, what are the other ones doing? Anyway, we set up an assay and we discovered a peptide hormone that was called RALF because it was previously discovered as rapid alkalinizing factor. You don't have to understand all that stuff. We did a bunch of biochemistry, we sequenced it, and we found that there's actually 34 members of the RALF family. We discovered RALF one which is the most highly expressed member of the family. 

We now know exactly how it acts. We now have to figure out what the other 33 are doing. I just wrote a grant to NSF for about $2 million, I'm optimistic but you never know these days, that will allow us to figure out what the other RALFs are doing and continue this research. One thing we do-- Let me explain how we do this. We're looking for proteins that get phosphorylated. What does that mean? When you add a phosphate to a serine or threonine or a tyrosine, that changes that activity and either makes it active or less active. We look for these proteins by doing something really cool. We grow the plants on N15 verses N14. N15 is normally, in nature, the isotopes of -- are on, 98% N14, 2% N15. What we do is we grow one batch on 98% N15 and one batch on 98% N14. 

We treat one of them with a hormone and the other one without. Then we grind them up together. We're looking for a protein that's been changed by that hormone. The way we do that is we use a mass spectrometer which separated the N15 from the N14 protein. We plow through tens of thousands of these pairs. Most of the pairs aren't like this where the N15 is the same height as the N14. That means it hasn't been affected by the hormone. But every once in a while you get one like this, and we reverse it in another experiment to correct for any possible effects of the neutron. When we see a peptide that looks like this here and like that there, bingo! We know we've got a peptide that's been changed by the hormone. We're using exactly this method to also look for biomarkers for colon cancer. 

Now wait a minute, how'd he get from a plant hormone to colon cancer? Let me explain. Again, we have two mice. This mouse has the gene that causes it to get colon cancer within nine months. It's identical to the human one. It's called APC or MINMOUSE, multiple intestinal neoplasma. This mouse is normal, this mouse has this mutation. We grow these mice in N14, we grow these mice in N15. I swear to God, you can grow a mouse in 98% N15. Every -- atom in that mouse has an extra neutron. We take blood from the two mice and we grind the blood up together and we do exactly the same thing. 

We're now looking for proteins in the blood that are high in the mutant mouse and normal in the normal. We went through 10,000 proteins and we found 30 that we think are candidate biomarkers for colon cancer. We're actually now testing them in a human population and some of them are looking really good. But it's the same basic procedure. For those of you that are technically-minded, I love adding neutrons. It turns out biology doesn't care if they have an extra neutron. They live perfectly normal. An N15 mouse and an N14 mouse, you can't tell the difference. Their behavior looks the same. In fact, we've also added a neutron to every carbon atom. 

Not in a mouse, it's very expensive. We've done it in a plant. I've made a plant that was 98% C13, normally it's C12, and 98% N15. I believe I could also make a plant that would be 98% O18. It's normally O16. I believe I can add a neutron to basically every element in an organism. A mouse, if we did it, would weight about 8% more, but it would weigh more because every atom has an extra neutron, not because it didn't exercise enough or it eat too much. There's a question, would that mouse know that it was overweight because of the neutron rather than-- It's a physiological question that's very interesting. The plant that has this extra neutron, it turns out it detects gravity a little better. It actually is a little better at detecting gravity, which makes sense because it's got a heavier cytoplasm. 

[inaudible] I'm sorry. >> What about hydrogen? >> No, no. Actually, that's a great question. When you go from H1 to H2, deuterium, you're doubling the size of the nucleus. That actually has a biological effect. You cannot go with more than 30% deuterium without killing a cell. But N15, N14 is a very small change that doesn't affect chemistry. This is physics verses chemistry. It's very interesting. Ah, physics verses biology. 

 I don't need to do the rest of this. So the receptor kinaes that we found is the receptor for this peptide hormone that controls cell expansion was previously discovered by a geneticist who was looking for plants that had reduced fertility. It turn out-- He named it Feronia. Feronia is very interesting. Feronia is the goddess of fertility in Etruscan society. What happens is when the pollen tube grows down to find the egg, when the pollen tube which carries two male nuclei gets near the egg cell in the plant, it explodes, releases those nuclei. In Feronia it does not explode, it grows past the female egg, and therefore it's reduced fertility. The reason it grows past is because this RALF and the receptor involved in the communication between the pollen tube and the egg. It's also, this receptor and its hormone, controlling expansion all over the plant, but in the flower it's particularly easy to genetically detect. It was found by this fellow and he named it Feronia. 

When you make a mutant this Feronia knockout, normally RALF causes plants to be-- This is a negatively acting hormone. Instead of human growth factor which positively regulates, this is a negative. And most things are either plus or minus and you can switch them very easily. This is a negatively acting-- It inhibits cell expansion, the hormone does. But when you make a knockout they actually grow a little faster, which again, it's a negatively acting receptor but it grows a little faster. The key is that the Feronia is completely resistant to RALF. Here's wild type, you can see RALF acting, but in Feronia it's RALF resistant here. These are just controls. These days to get a paper in Science you need to combine  genetics, biochemistry, physiology. You really have to have the whole story nailed down in every which way. 

Here's a bunch of mutants to show that the only receptor kinaes that is really RALF resistant is Feronia. One of the cool things about Wisconsin is that, we found a new member of this family and I wanted to follow my Swiss colleague's gods and goddesses naming thing but I didn't read those books in college. I really should have because I really know very little about classics. I teamed up with this guy. He is William --. Has anyone heard him talk yet? You will. Wisconsin just got a 15 year contract to take over the Troy excavation site in Turkey on the Mediterranean, actual ancient Troy. This fellow has spent his entire career studying Troy. He goes there every summer with 20 or 30 undergraduates. He came to me because he wants to use archeogenomics. 

He wants to study ancient DNA and he didn't know anything about it. I actually gave him a lab upstairs and we're starting to do a lot of work together trying to sequence DNA from ancient teeth that he digs up from Troy. I mean, this is 8,000 year old Troy. If any of you want to visit the site and talk to him, I strongly encourage you. It's a great opportunity. So, oh! So when it came time to name this family, this new gene, I didn't even know where Etrusca was. It turns out it was like a 500 year civilization in Italy before the Greeks. This was a big deal. [inaudible] Excuse me. >> Before the Romans. 

>> Before the Romans, right. He gave us a few extra names. We named our gene Erelus, who is the son of Feronia. Then next one we're going to name Hippolyta, who is actually the daughter of Zeus, the Queen of the Amazons, that has this girdle that Zeus gave her for power. This is like Aaron Rodgers I think. It's going to work out fine. It's not a reason to do the work just to be able to name a gene. [laughter] But it's pretty cool. Okay, let me quickly go through everything. You don't need to know this. 

I have, I think I may not show this, there's an organism that make silica houses known as a diatom. It actually fixes 30% of the world's CO2 every year. We've discovered genes involved in these glass houses. We believe it has actually a big impact on carbon fixation and where that carbon goes. It actually helps these diatoms fall to the bottom of the ocean. 30% of the worlds CO2 is actually fixed. I actually have a movie. Ah, you gotta see this movie. It's a cool movie. I'm not going to show you the eel and the alligator. 

This is an actual satellite image of a year of carbon. Now, green and yellow are high CO2 fixation. Blue and white is very little. Here's Australia, this is Asia, now we're coming to Africa. The Sahara Desert fertilizes the ocean. It deposits FE and allows diatoms to grow. There's the mouth of the Amazon. A lot of CO2 fixation. But here's a bloom in the ocean that took about two months. You see that bloom? That is a single species of algae known as a diatom, and it's silica requiring. 

My lab discovered which genes are involved in making that silica house. These are genes that we know nothing about. So here's an organism that fixes 30% of the CO2 on Earth, and there's only like ten people working on it. It's always amazed me. But the problem is, oceanography and molecular biology have never really gotten together very much. If any of you are looking for a career, and you don't want to go into neurobiology which is really hot these days, if you like the ocean and you want to be out in the wild, if you can combine your knowledge of molecular biology with your knowledge of environment and ecology and global cycles, there's a bad need for you in that area. The Navy, because all the organisms in the ocean are limited by FE, the Navy hypothesized that we could actually reverse global warming by fertilizing the ocean. They blow up some ships and deposited all that FE, then they calculated how many ships they'd have to blow up to reverse global warming. It's within the range of do-ability. I hope they don't do it though, because if they screw it up we don't have a second shot. 

You know what I mean? It's not the kind of experiment you can repeat. So it's there if it's absolutely desperate, that knowledge is there. But we don't want to do that. We don't want to do that. Anyway, I'm not going to show you this eel killing an alligator, but if you go to YouTube and you type in alligator and electric eel you'll see a cage match. It was filmed by somebody down there. It just shows you the power of an electric eel. This is the paper we've just submitted to Science where hopefully it'll get in. I went on a boat, my daughter was there too, for a week, up the Nanay river, a tributary. When you go with these electric fish ichthyologists, the way you go fishing with them is, you have a wooden pole with two electrodes connected to an amplifier and headphones. 

You stick it in the water or the mud, and then you can hear the electric organ discharge. This 'eeeee'. It's a certain frequency. Each fish has a slightly different frequency. When you hear it, you go in there with nets and you catch them. It's really quite awesome. What's amazing is that these are all the fish in nature. These lightning bolts are where the electric organ appears. Six times the electric organ has independently evolved, independently evolved. We've sequenced three of the six species of fish and we've looked for proteins that are found in all three species, regulatory proteins. 

We've actually got a list of about 30 that we believe are critical for formation of the electrocyte from a myocyte. This is some of them. Unless you're a molecular biologist this won't mean anything to you. Red is a gene going up and green is a gene going down. You can see that in the electricus-- These are the other electric fish. A set of genes that are all going down. These are involved in down regulating muscledness. So these electrocytes that converted contractibility into electrogenicity. They stopped the ability to contract and raised the ability to create voltage. We believe these are the common genes that nature has in its tool kit. 

When we get around to engineering an electric organ in a test tube, these are the genes we're going to use. Now that we know it's less than 30, you can actually do experiments with these genes if you want to make an electric zebra fish, for example, with an electric organ. These are the kind of things. Now whether or not it's ethical for me to do that, whether I'm making something that's a monster or something that's useful is up to you to decide. Don't let scientists make that decision. I do want to end with conclusions. It's the interdisciplinary which is the most exciting right now. I'm talking not just like biology and ecology, I'm talking about physics, math, chemistry. We are entering a time where genetic manipulation is commonplace. We don't know how fast it will occur, but it is inevitable. 

What you don't want is this. You don't want to engineer a farmer with a stool and a cow with a stool. They're not matched. Obviously, that would be a disaster. For Wisconsin, for a while we harvested our paper and lumber, we did oar. Now we're doing crops and cows and cheese. But it could be that the discoveries being made on this campus and other campuses around the state can be converted into knowledge that can be useful for society.  I want to leave off with something inspirational. I've always found it inspirational to think that we've actually walked on another piece of dirt out there in space. Basically I'm saying, "Although there are many ethical, legal and social issues we will need to grapple with in the coming age of genetic engineering, I'm an optimist. 

I believe that the future is so bright" our cows will have to wear shades. [laughter] I do want you to know that this is the end. And there it is. [laughter] These are the people who do work in my lab. Miyoshi Haruta especially I wanted to mention. She worked her ### off for four years together with Kelly and Ben who are co-authors on the paper. I just tell jokes. That's it. [applause]