WEBVTT - Meeting Mr. DNA 0:00:00.160 --> 0:00:07.200 Brought to you by Toyota. Let's go places. Welcome to 0:00:07.360 --> 0:00:15.480 Forward Thinking. Hey there, and welcome to Forward Thinking, the 0:00:15.520 --> 0:00:18.520 podcast that looks at the future and says, inside the 0:00:18.600 --> 0:00:22.919 cell is a tiny double helix another fancy word or 0:00:23.040 --> 0:00:27.520 d n A. I'm Jonathan Strickland and I'm Joe McCormick. 0:00:27.560 --> 0:00:30.000 And today we're gonna be recording the first part of 0:00:30.040 --> 0:00:33.200 a two part episode on one of the most interesting 0:00:33.240 --> 0:00:36.640 molecules in the entire universe. Dare I say the single 0:00:36.760 --> 0:00:40.000 most interesting molecule. I mean it depends on if you 0:00:40.080 --> 0:00:43.600 like yours at your nucleic acids being ribos oriented or 0:00:43.680 --> 0:00:47.640 de ox. Get that ribos out of my head. This 0:00:47.720 --> 0:00:49.519 is d n A. It's d n A time. So 0:00:49.520 --> 0:00:51.880 this is gonna be part one. Uh, and today we're 0:00:51.960 --> 0:00:55.520 going to mostly be focusing on the history and the 0:00:55.600 --> 0:00:59.160 current research around using DNA. But please stick with us 0:00:59.160 --> 0:01:02.160 also for next time when we're going to focus on 0:01:02.520 --> 0:01:06.440 some topics aroun using DNA as a technological tool. Yeah, 0:01:06.600 --> 0:01:09.960 and uh, as we record this, it is April twenty five, 0:01:10.120 --> 0:01:14.759 which is National DNA Day. Complete coincidence, but a lovely coincidence. Yes, 0:01:15.120 --> 0:01:17.600 I had no idea. Yeah, we didn't. I just happened 0:01:17.600 --> 0:01:18.959 to find it while I was doing a search on 0:01:19.080 --> 0:01:22.600 news about DNA. And the reason it is National DNA 0:01:22.720 --> 0:01:25.440 Day is that on this day in two thousand three, 0:01:25.480 --> 0:01:29.959 the Human Genome Project completed its quest to to map 0:01:29.959 --> 0:01:33.520 out the human genome. So there you go, Happy National 0:01:33.640 --> 0:01:39.000 DNA Day. So where's the treasure buried? Sadly, we don't 0:01:39.040 --> 0:01:41.959 have all the information necessary to find the treasure? Here 0:01:42.000 --> 0:01:44.000 here's the last part is stored in an our two 0:01:44.120 --> 0:01:47.240 unit that we came. Yeah, it was not going to 0:01:47.360 --> 0:01:50.680 go down the force unleashed path of logic. There in 0:01:50.800 --> 0:01:53.320 lies madness. But I do want to say that I 0:01:53.360 --> 0:01:55.680 read us an interesting thing from one of the researchers 0:01:55.680 --> 0:01:59.600 who worked on the genome project, and because they're often asked, well, 0:01:59.640 --> 0:02:01.760 if you mapped out the genome, why haven't we cured 0:02:01.800 --> 0:02:04.720 cancer yet? Right, And they said, well, think of it 0:02:04.760 --> 0:02:08.800 this way. Imagine that the human genome is really a 0:02:08.800 --> 0:02:13.160 collection of ancient books written in a language no one 0:02:13.520 --> 0:02:18.720 speaks or writes in anymore. You have just spent more, 0:02:18.720 --> 0:02:21.359 you know, a decade or more, collecting all of the books, 0:02:21.400 --> 0:02:24.520 and now you are absolutely certain that you have all 0:02:24.600 --> 0:02:27.560 the books that make up the entire collection of this 0:02:27.600 --> 0:02:31.760 one library, but just still can't read them yet, all 0:02:31.840 --> 0:02:33.200 of them, or at least not all of them. And 0:02:33.240 --> 0:02:35.040 that's what is going to be taking up a lot 0:02:35.080 --> 0:02:38.760 of time for the next decade or so while we 0:02:38.800 --> 0:02:41.639 while we learn what these books say and what they 0:02:41.680 --> 0:02:45.040 mean and how to use them. Yeah. Right now we've 0:02:45.080 --> 0:02:48.320 got the equivalent of like run spot run yeah, or 0:02:48.440 --> 0:02:52.600 go spot go. I'm behind on my board book titles. 0:02:52.919 --> 0:02:55.280 Let's see Dick and Jane is what you're talking about? 0:02:55.720 --> 0:02:58.359 That that kind of thing. But uh, but yeah, So 0:02:58.360 --> 0:03:01.240 so today, in this first episode, we wanted to just 0:03:01.280 --> 0:03:04.080 talk about what DNA is and what it is being 0:03:04.360 --> 0:03:07.120 used for currently. Look go into a little bit of 0:03:07.160 --> 0:03:10.880 the history of of how it was potentially created here 0:03:10.919 --> 0:03:14.360 on the planet Earth, and also how we discovered it, 0:03:14.440 --> 0:03:17.680 because you know, it's a relatively resdiscovery in human history, right, 0:03:18.000 --> 0:03:20.680 So let's start with the basics at base. DNA is, 0:03:20.720 --> 0:03:22.760 of course chemistry, but as we all know, it's the 0:03:22.800 --> 0:03:25.760 basis for all of the stuff we know of in 0:03:25.800 --> 0:03:29.959 the universe that is definitely in the alive category, though 0:03:30.000 --> 0:03:33.120 maybe not some things that are just maybe sort of alive, 0:03:33.240 --> 0:03:36.160 like prions and we're not going to do all the 0:03:36.200 --> 0:03:39.520 standard stuff you learned in school about what DNA does, 0:03:39.640 --> 0:03:42.920 but just for a brief refresher, the really simple version, 0:03:43.040 --> 0:03:45.560 what does DNA do well. You can think about your 0:03:45.600 --> 0:03:48.640 body as a type of machine, and that machine is 0:03:48.680 --> 0:03:51.600 made up of parts, and most of these parts are proteins. 0:03:51.960 --> 0:03:56.360 Proteins are like tiny, very simple robots that work together 0:03:56.680 --> 0:03:59.720 to make more complex robots that are your organs, which 0:03:59.720 --> 0:04:02.360 of course has work together to make the real robot, 0:04:02.400 --> 0:04:06.960 which is you. But they're all these little robots in 0:04:07.000 --> 0:04:10.280 your body and their proteins. So what makes these proteins. 0:04:10.400 --> 0:04:12.920 The answer is d n A. DNA or de oxy 0:04:13.040 --> 0:04:17.480 ribonucleic acid, is a long chain molecule. It's one really 0:04:17.560 --> 0:04:22.000 huge long molecule that contains an ordered sequence of what 0:04:22.040 --> 0:04:24.760 are called nucleotides. These are the building box of the 0:04:24.839 --> 0:04:27.919 d n A and the sequence of the nucleotides, what 0:04:28.080 --> 0:04:31.800 order they come in determines what proteins get made and 0:04:31.839 --> 0:04:34.440 how they get used. So DNA, you can think of 0:04:34.480 --> 0:04:37.080 it as like both the code for what your body 0:04:37.200 --> 0:04:41.000 should be like and also the machine that builds the 0:04:41.080 --> 0:04:45.159 machines that builds the machines that build your body, one 0:04:45.160 --> 0:04:48.200 protein at a time. Now, if you find all that confusing, 0:04:48.279 --> 0:04:51.280 you can just refer to the helpful educational film Mr 0:04:51.400 --> 0:04:54.240 DNA at the beginning of Jurassic Park, which is so 0:04:54.279 --> 0:04:58.159 good is actually, where did you come from? I watched 0:04:58.160 --> 0:05:02.280 it again before we before we recorded the show. So 0:05:02.360 --> 0:05:05.479 let's talk about, like, well, where do we think DNA 0:05:05.640 --> 0:05:08.600 came from? Like where? What? Why? We know that it's 0:05:08.760 --> 0:05:13.680 it's integral to life here on Earth. How did it 0:05:13.960 --> 0:05:17.560 get started? That's a really interesting question, and it's easily 0:05:17.600 --> 0:05:20.240 a whole episode in itself, So we can't explore that 0:05:20.480 --> 0:05:22.080 entirely here if we want to get to all the 0:05:22.080 --> 0:05:23.839 other stuff we were going to talk about today. But 0:05:24.160 --> 0:05:26.960 the short answer is this is still a really big, 0:05:27.080 --> 0:05:30.880 unsettled question in the origins of life in biochemistry. We 0:05:31.000 --> 0:05:34.320 have some good ideas, but nobody really knows with confidence 0:05:34.400 --> 0:05:37.440 yet where DNA came from an exactly what role it 0:05:37.480 --> 0:05:40.160 played in the emergence of life on Earth, for example, 0:05:40.520 --> 0:05:43.720 one big question, Like we said earlier, DNA is the 0:05:43.760 --> 0:05:46.440 basis of pretty much all life on Earth today, But 0:05:46.640 --> 0:05:51.160 which came first? D NA or life? Was there non 0:05:51.279 --> 0:05:54.640 DNA based life before there was DNA based life? Yeah, 0:05:54.680 --> 0:05:56.120 it's one of those chicken or the egg kind of 0:05:56.200 --> 0:05:59.480 kind of questions. Exactly it really is and uh, it's 0:05:59.760 --> 0:06:02.279 the There have been plenty of people looking into trying 0:06:02.360 --> 0:06:06.600 to at least hypothesize where DNA came from, whether or 0:06:06.680 --> 0:06:10.159 not it was a product of some early form of life, 0:06:10.240 --> 0:06:13.120 or if in fact it was the thing that allowed 0:06:13.240 --> 0:06:16.400 life to emerge. Yeah, and one issue here is that 0:06:16.600 --> 0:06:20.640 DNA is a it's a very complex molecule. It doesn't 0:06:20.960 --> 0:06:23.440 and so for this reason, people generally don't think it 0:06:23.440 --> 0:06:26.840 looks like something that would randomly self as symbol without 0:06:26.920 --> 0:06:30.680 some sort of precursor. Uh. And so a lot of 0:06:30.720 --> 0:06:33.800 the question that allow the investigations on where did DNA 0:06:33.880 --> 0:06:35.480 come from? Or looking at like well, what could a 0:06:35.560 --> 0:06:40.000 chemical precursor be? What could there have been that facilitated 0:06:40.040 --> 0:06:43.320 the creation of this really complex molecule. And one very 0:06:43.360 --> 0:06:45.760 popular theory, though we don't know it's the answer yet, 0:06:45.839 --> 0:06:49.599 it's a strong hypothesis, is the so called RNA world 0:06:50.120 --> 0:06:55.200 So ribonucleic acid. Yeah, this is a somewhat simpler molecule 0:06:55.240 --> 0:06:58.559 than dnah. Yeah, Yeah, let's clarify the difference there between 0:06:58.560 --> 0:07:01.279 the two. All right, So they're both nuke aic acids. Uh, 0:07:01.480 --> 0:07:04.039 First of all, the sugar element of the nucleic acids 0:07:04.240 --> 0:07:07.039 that they're composed of a sugar element as well some 0:07:07.080 --> 0:07:09.240 other pieces, But the sugar element is different from both. 0:07:09.320 --> 0:07:13.760 You have de oxy ribos for DNA and just ribos 0:07:13.920 --> 0:07:17.600 for RNA. That's that's a major difference right there. Who 0:07:17.400 --> 0:07:21.040 who Who gets out of bed for ribos? Really, you 0:07:21.040 --> 0:07:23.680 got to hold out for that d oxy ribos if 0:07:23.680 --> 0:07:26.160 you if you're lacking DNA, you're not kicking out of bed. 0:07:26.800 --> 0:07:31.480 DNA is double stranded. You always think of that that classic, uh, 0:07:31.800 --> 0:07:35.440 double helix twisted ladder we'll talk about in a minute. 0:07:35.760 --> 0:07:39.720 RNA is a single strand molecule. DNA stores and transfers 0:07:39.720 --> 0:07:43.200 genetic information and humans. RNA codes for amino acids and 0:07:43.240 --> 0:07:45.960 acts kind of like a messenger between DNA and ribosomes 0:07:46.000 --> 0:07:49.160 to make proteins. So those are the differences. So let's 0:07:49.200 --> 0:07:51.080 talk about some of the research. In two thousand nine, 0:07:51.120 --> 0:07:54.480 a group of scientists successfully synthesized two of the four 0:07:54.560 --> 0:07:58.800 nucleotides that make up RNA using chemicals that we believe 0:07:59.040 --> 0:08:03.720 we're present on primordial Earth. So this does not necessarily 0:08:03.720 --> 0:08:06.680 mean that the hypothesis is true. It just means it 0:08:06.720 --> 0:08:09.000 makes it sort of plausible, at least for urna right, 0:08:09.080 --> 0:08:14.520 that RNA could spontaneously form based upon some conditions on Earth. 0:08:14.960 --> 0:08:17.920 And again, it's only the proof of two of those 0:08:17.920 --> 0:08:20.320 four nucleotides. They're still working on the other two to 0:08:20.360 --> 0:08:23.080 see if there's a way that the chemicals that we 0:08:23.240 --> 0:08:27.360 think we're around in primordial Earth could have developed into 0:08:27.400 --> 0:08:31.080 these building blocks for RNA. Um Now, one of those 0:08:31.080 --> 0:08:34.000 scientists have since has since gone on to see if 0:08:34.040 --> 0:08:37.360 he can do the same thing with DNA nucleotides using 0:08:37.400 --> 0:08:42.040 a similar approach to that RNA experiment. Uh, but sugars 0:08:42.280 --> 0:08:45.440 in DNA nucleotides are harder to work with in RNA 0:08:45.640 --> 0:08:50.120 counterparts before you actually assemble into DNA. Once it's assembled 0:08:50.120 --> 0:08:54.120 in DNA, it's really stable. Yeah, but before then it's 0:08:54.280 --> 0:08:57.280 just tough to work with. So ultimately, we still don't 0:08:57.320 --> 0:09:02.760 know if RNA and so DNA preceded life, but at 0:09:02.840 --> 0:09:05.440 least the work that we've seen so far suggests that 0:09:05.559 --> 0:09:10.880 it's still plausible. It's it's not necessarily um a dead 0:09:10.960 --> 0:09:13.600 end yet until we get to a point that we 0:09:13.679 --> 0:09:17.480 have to say, well, we've tried everything. We can't get 0:09:17.480 --> 0:09:19.600 any of these chemicals to work out the way we 0:09:19.640 --> 0:09:22.440 thought it would back on the primordial Earth conditions. Maybe 0:09:22.480 --> 0:09:26.000 there's an alternative answer to this question. Yeah, it's a 0:09:26.040 --> 0:09:29.640 fascinating question, absolutely crazy that we don't know the answer 0:09:29.679 --> 0:09:32.000 to this, and so it's so exciting to read about, 0:09:32.200 --> 0:09:34.400 you know, what we're learning. Yeah, so it's so big 0:09:34.400 --> 0:09:39.400 and basic. Other research that I've read indicated that another factor, 0:09:39.480 --> 0:09:43.200 meteor impacts in primordial Earth, might have been the key 0:09:43.240 --> 0:09:46.160 to putting all of this together. Um and Okay. One 0:09:46.160 --> 0:09:49.160 of the theories about how DNA and life in general 0:09:49.200 --> 0:09:53.080 arose on Earth is that amino acids and nucleotides hitched 0:09:53.080 --> 0:09:56.080 a ride here on meteors and other bodies that you know, 0:09:56.120 --> 0:10:00.600 we're from elsewhere, and that's how they got here. Now, 0:10:00.640 --> 0:10:02.679 of course that doesn't answer the question of how they 0:10:02.720 --> 0:10:05.840 were assembled, but that's how they arrived on this planet. Sure, 0:10:05.880 --> 0:10:07.520 which is you know, yeah, it's it's a it's a 0:10:07.720 --> 0:10:10.880 set of questions that also go together. Clearly, the lizard 0:10:10.920 --> 0:10:13.160 people put it together, right, and they put it on 0:10:13.280 --> 0:10:16.080 rocks and pushed them to Earth. Well, absolutely, is that 0:10:16.120 --> 0:10:19.480 what you call those naked dudes in prometheus lizard people 0:10:20.640 --> 0:10:24.920 I call them frequently. Go ahead, Lauren, excellent. So there 0:10:24.960 --> 0:10:28.080 has been though skepticism in the research community about whether 0:10:28.320 --> 0:10:31.880 that the breadth of amino acids and nucleotides that we 0:10:31.920 --> 0:10:35.520 see here on Earth could have possibly arrived intact, or 0:10:35.559 --> 0:10:39.520 even could have formed from things that might have arrived intact. 0:10:40.600 --> 0:10:42.640 But so there was the study that was published back 0:10:42.640 --> 0:10:46.559 in August by team out of Japan, and they simulated 0:10:46.840 --> 0:10:50.840 a meteorite hitting an ancient ocean, and they found that 0:10:50.880 --> 0:10:54.480 the energy from the impact, together with the raw physical 0:10:54.559 --> 0:10:57.680 materials that the inorganic compounds that were likely to have 0:10:57.720 --> 0:11:02.000 been present, could indeed have formed armed nucleo nucleotides and 0:11:02.080 --> 0:11:05.040 amino acids. They they found when they when they studied 0:11:05.040 --> 0:11:09.040 their post impact stuff, they found nine amino acids that 0:11:09.080 --> 0:11:11.880 are all involved with the formation of proteins and also 0:11:12.040 --> 0:11:17.079 to nucleotides. So that's that's pretty fascinating. That's really an 0:11:17.120 --> 0:11:21.520 interesting idea. And obviously, if we were to study this 0:11:21.600 --> 0:11:26.000 further and and conclude that in fact these molecules were 0:11:26.000 --> 0:11:29.040 extraterrestrial in nature, as Joe was pointing out, that then 0:11:29.160 --> 0:11:32.760 leads to a whole new series of questions. Which or 0:11:32.840 --> 0:11:36.440 maybe even more interesting. Yeah, yeah, the and it may 0:11:36.480 --> 0:11:40.400 be that perhaps these are questions that are are ultimately 0:11:40.480 --> 0:11:43.760 unknowable to us. We don't know, maybe that that we 0:11:43.800 --> 0:11:48.480 will have a certain percentage of certainty for one versus another, 0:11:49.120 --> 0:11:52.640 but uh, I'm not entirely certain short of time travel, 0:11:52.720 --> 0:11:56.720 how we would ever get to the very bottom of this, like, 0:11:56.760 --> 0:12:00.800 what would be the the conclusive proof that would uh 0:12:01.040 --> 0:12:04.760 make one hypothesis stand well over the other. It seems 0:12:04.800 --> 0:12:07.120 like probably the best we could hope to do is 0:12:07.160 --> 0:12:10.880 if we could offer a lot of hypotheses and note 0:12:10.920 --> 0:12:14.360 that eventually one of them works under lab conditions and 0:12:14.360 --> 0:12:17.960 the others don't, which gives you some degree of confidence 0:12:18.000 --> 0:12:20.679 that that's probably the right answer. But we'll never really know, 0:12:20.880 --> 0:12:25.200 right right, it's not really approvable hypothesis. Um but but hey, okay, so, 0:12:25.240 --> 0:12:27.679 speaking of time travel, we have here in the studio 0:12:27.720 --> 0:12:31.480 with us today the way back machine from tech stuff, Yeah, 0:12:31.559 --> 0:12:33.319 tech stuff and stuff you should know. I mean, it's 0:12:33.360 --> 0:12:35.200 been a long time since I've seen this baby, and 0:12:35.200 --> 0:12:37.160 I gotta tell you it's a little worse for wear. 0:12:37.200 --> 0:12:39.400 I'm pretty sure the stuff you should know, guys have 0:12:39.520 --> 0:12:43.079 been going back to the sixties for some fun. But yeah, 0:12:43.160 --> 0:12:45.960 let's us and chalk. Let's put it to use and 0:12:46.000 --> 0:12:48.680 really find out. Like, let's let's talk about the actual 0:12:48.760 --> 0:12:51.679 discovery of d n A, not not when it was 0:12:52.200 --> 0:12:55.200 potentially first formed on Earth, but when we humans first 0:12:55.200 --> 0:12:58.040 became aware of it. Okay, well, you may have heard 0:12:58.080 --> 0:13:00.720 this story before. Of course. The answer is that Watson 0:13:00.720 --> 0:13:04.240 and Crick discovered DNA in the nineteen fifties. Except that's 0:13:04.280 --> 0:13:09.199 not true. But the book told me, no, this is 0:13:09.240 --> 0:13:12.880 the thing for some reason, even my I've read about 0:13:12.920 --> 0:13:15.560 this before, and even my brain goes to this place. Yeah, 0:13:15.559 --> 0:13:19.679 Watson and Crick discovered DNA. That's not true. Uh so 0:13:19.760 --> 0:13:22.400 who really did discover d NA? What is it that 0:13:22.440 --> 0:13:26.160 Watson and Crick supposedly discovered or or contributed to our 0:13:26.240 --> 0:13:31.040 understanding of DNA. One interesting fact to point out, people 0:13:31.160 --> 0:13:34.800 knew about heredity before they knew about DNA, and this 0:13:34.880 --> 0:13:36.920 is a thing that can easily be lost because we 0:13:37.000 --> 0:13:40.400 now equate to DNA in standard conversation with the idea 0:13:40.440 --> 0:13:45.079 of heritable and information. So you get stuff from your parents, 0:13:45.240 --> 0:13:47.400 people just say, oh, it's in your d n A. 0:13:47.880 --> 0:13:51.079 But that that is a relatively recent thing to enter 0:13:51.120 --> 0:13:55.079 the common parlance, and so people knew about inheriting traits 0:13:55.120 --> 0:13:58.520 from parents long before they knew what the molecule was 0:13:58.559 --> 0:14:01.800 in the body that conveyed that information. Right, right, So 0:14:01.880 --> 0:14:04.240 in order to get to the bottom of this question, 0:14:04.280 --> 0:14:06.600 we're going to go back in our way back machine 0:14:06.880 --> 0:14:10.439 to eighteen sixty nine. Oh, that's why the numbers are. 0:14:10.640 --> 0:14:12.880 I was wondering. I just thought that was just randomly 0:14:12.920 --> 0:14:15.520 put there when I was saying sixties, I actually did 0:14:15.520 --> 0:14:19.280 me the eighteen sixties. Well, what were there good party 0:14:19.280 --> 0:14:22.400 times there too? I just assumed if Josh and Chuck 0:14:22.400 --> 0:14:24.560 were doing it. But now I know that nine was 0:14:24.600 --> 0:14:27.200 set for us. You ever seen Gone with the Wind, 0:14:27.240 --> 0:14:30.560 there's lots of parties. Yeah right, let's just don't look 0:14:30.600 --> 0:14:31.840 like a lot of fun. Let's just get in the 0:14:31.840 --> 0:14:40.840 way back machine and go check out where we're going. Okay, 0:14:40.840 --> 0:14:45.120 we're here, and there's so much pus. So in eighteen 0:14:45.160 --> 0:14:49.680 sixty nine, there's this Swiss biochemist at the University of 0:14:49.680 --> 0:14:53.680 tubing In and his name is Johann Friedrich Mescher, and 0:14:53.840 --> 0:14:58.840 he was studying puss. That explains this then, no joke. Yeah, 0:14:58.880 --> 0:15:03.440 so there's plus everywhere. Mitscher had a. He had an arrangement, 0:15:03.520 --> 0:15:07.320 you might say, with a nearby surgical clinic that would 0:15:07.400 --> 0:15:10.840 send him filthy used bandages that were dripping with pus. 0:15:11.360 --> 0:15:14.360 And you know, when you think about filthy used bandages 0:15:14.440 --> 0:15:17.360 dripping with pus, most people you wouldn't want to handle them, 0:15:17.480 --> 0:15:19.960 you know, do things with them, spend your Saturday on them. 0:15:20.080 --> 0:15:21.960 Not not way up on my list of things to do. 0:15:22.160 --> 0:15:24.920 But in fact, these pus soaked bandages turned out to 0:15:24.960 --> 0:15:29.080 be a scientific gold mine because of the following reason. 0:15:29.360 --> 0:15:34.040 So plus contains mostly dead lucacites, which are white blood cells. 0:15:34.920 --> 0:15:37.760 He was studying these white blood cells to understand the 0:15:37.760 --> 0:15:40.760 proteins in them. But Mescher also discovered in the course 0:15:40.760 --> 0:15:43.680 of his research that in the nucleus of each of 0:15:43.720 --> 0:15:46.960 the white blood cells there was a common substance that 0:15:47.040 --> 0:15:51.160 had nitrogen and phosphorus atoms in it and which was 0:15:51.240 --> 0:15:54.800 chemically distinct from the protein. So it's this stuff there 0:15:54.840 --> 0:15:57.840 in the cell nucleus. It's not a protein. It's got 0:15:57.920 --> 0:16:02.040 nitrogen and phosphorus. It is it. And he called this 0:16:02.080 --> 0:16:06.840 stuff nucleon, which later became known as nucleic acid. And 0:16:06.920 --> 0:16:09.880 once it was totally isolated from the surrounding proteins and 0:16:09.920 --> 0:16:12.640 all the other stuff. The pure molecule got the name 0:16:12.680 --> 0:16:17.440 we know today de oxy ribonucleic acid or d n A. Well, 0:16:18.400 --> 0:16:20.360 this is fascinating, Joe, but I would like us all 0:16:20.440 --> 0:16:22.720 to take a pledge that none of us will utter 0:16:22.760 --> 0:16:25.760 the word PUS again in the rest of this episode. 0:16:26.880 --> 0:16:31.200 I will with with one small exception, and that is, 0:16:31.320 --> 0:16:34.720 can we get out of this PUS party? I would 0:16:34.800 --> 0:16:36.800 I would like, do you have any parties to take 0:16:36.880 --> 0:16:39.440 us to that aren't made of pus? Well, let's see 0:16:39.560 --> 0:16:43.960 where we could go on the quickly summarized scientific research 0:16:44.000 --> 0:16:48.080 bandwagon party. Well, luckily there's a montage button inside the 0:16:48.080 --> 0:16:50.360 way back machines and just hit that. Yeah, now we 0:16:50.440 --> 0:16:52.760 gotta go on the montage because there are actually a 0:16:52.800 --> 0:16:56.360 bunch of scientists over the ensuing decades that contributed a 0:16:56.360 --> 0:16:58.480 lot more to the study of heredity and d n A, 0:16:58.560 --> 0:17:00.160 And we don't have time to go into all of 0:17:00.160 --> 0:17:03.600 their research. But but so after me share at this point, 0:17:04.080 --> 0:17:06.600 you know that there are genes that convey traits from 0:17:06.600 --> 0:17:09.000 parents to offspring, and we know about DNA, but we 0:17:09.040 --> 0:17:11.800 hadn't put them together. We didn't know that one was 0:17:11.920 --> 0:17:16.639 the DNA was the agent of heredity. And so in 0:17:16.760 --> 0:17:20.760 nineteen forty four group of scientists Avery, McLeod and McCarty 0:17:21.080 --> 0:17:24.760 showed that DNA conveys hereditary traits, that DNA is the 0:17:24.840 --> 0:17:28.879 agent of mendalian genetics. And finally, in nineteen fifty three, 0:17:29.320 --> 0:17:32.720 you finally got to Krick and Watson, plus a couple others, Actually, 0:17:32.920 --> 0:17:37.800 Francis Crick, James Watson, Maurice Wilkins, and Rosalind Franklin demonstrated 0:17:37.840 --> 0:17:41.320 the structure of DNA. So they put together the model 0:17:41.400 --> 0:17:44.640 of the double helix molecule of DNA, the one we've 0:17:44.680 --> 0:17:47.080 all seen now. It looks like a ladder that you 0:17:47.200 --> 0:17:51.679 twisted up like a spring or like a like a 0:17:51.960 --> 0:17:56.880 like a spiral staircase. Yeah, yeah, spiral ladder, I guess, yeah. Uh. 0:17:56.920 --> 0:18:00.480 And so it's got two spiraling parallel pull ales that 0:18:00.520 --> 0:18:05.080 are connected by rungs of nucleo basis. And the important 0:18:05.080 --> 0:18:08.639 thing about discovering the double helix shape of the molecule 0:18:08.760 --> 0:18:11.760 was that this showed how the DNA molecule was capable 0:18:12.280 --> 0:18:16.840 of conveying genetic information. Well, let's let's go ahead and 0:18:16.880 --> 0:18:19.720 pop on back over into a modern day and back 0:18:19.760 --> 0:18:24.400 into our studio and and and just concentrate more about 0:18:25.160 --> 0:18:35.960 uh little other stuff we've learned about this amazing molecule. Okay, yes, 0:18:36.080 --> 0:18:38.760 this is better for reasons that I've promised not to 0:18:38.800 --> 0:18:44.800 mention again. Um okay, Joe, you are so lucky the 0:18:44.800 --> 0:18:48.280 the Acts of Mysticism is not currently in the podcast studio. 0:18:49.640 --> 0:18:51.880 Not the Mystical Acts. You never used the Mystical Acts 0:18:51.920 --> 0:18:56.199 as a weapon. I'm sorely tempted. Okay. So, despite this 0:18:56.400 --> 0:19:00.159 rich history of research into into DNA, there's still so 0:19:00.280 --> 0:19:01.879 much that is going on in the field, all these 0:19:01.920 --> 0:19:05.679 studies being conducted, questions being answered, new questions that we 0:19:05.800 --> 0:19:09.679 never even conceived of being posed. And so so we 0:19:09.720 --> 0:19:11.800 wanted to give y'all a quick sample of some of 0:19:11.800 --> 0:19:13.600 the stuff we've seen recently, just to give you an 0:19:13.640 --> 0:19:17.919 idea of of what kind of things are going on. Yeah. So, 0:19:18.040 --> 0:19:20.879 first of all, we were talking about that double helix shape. 0:19:21.400 --> 0:19:24.520 One of the interesting bits of research that we encountered 0:19:24.520 --> 0:19:28.480 while looking into the topic was that some scientists have 0:19:28.680 --> 0:19:32.400 shown that DNA doesn't just hold that double helix shape. Yeah, 0:19:32.440 --> 0:19:34.240 it actually comes in lots of fun shapes. Yeah. So 0:19:34.320 --> 0:19:36.680 I as I as I said, is it kind of boogies. 0:19:37.160 --> 0:19:39.360 It moves around a lot. And actually, when you think 0:19:39.400 --> 0:19:43.199 about get stars, moons and balloons and clovers, it's not 0:19:43.240 --> 0:19:46.320 the Lucky Charm shapes, although some of them are similar 0:19:46.359 --> 0:19:49.400 to them. All right, So what's the deal here. We've 0:19:49.400 --> 0:19:52.439 been told about this double helix shape forever. Why are 0:19:52.440 --> 0:19:56.160 we suddenly seeing different shapes? Well, part of what I've 0:19:56.200 --> 0:19:59.920 read is that when Watson and Crick were really described 0:20:00.160 --> 0:20:02.400 the structure of DNA, they were looking at a length 0:20:02.400 --> 0:20:05.320 of DNA that was about twelve base pairs long, something 0:20:05.359 --> 0:20:09.040 like that, like one turn of DNA. But DNA has 0:20:09.080 --> 0:20:11.080 to turn many, many, many times. It has to be 0:20:11.240 --> 0:20:15.639 super coiled because DNA is a very long molecule. But 0:20:15.680 --> 0:20:18.680 it has to fit within the nucleus of a cell, right, 0:20:18.760 --> 0:20:22.119 And most nucleus nucleus is nuclei of cells are not 0:20:22.240 --> 0:20:24.679 a few meters long. It really the length of a 0:20:24.760 --> 0:20:28.280 DNA chain, right, So to fit that inside a cell's nucleus, 0:20:28.320 --> 0:20:31.000 you have to coil and coil and coil and coil. 0:20:31.119 --> 0:20:34.240 This this shape. And if you've ever dealt with any 0:20:34.280 --> 0:20:37.600 kind of like cable or anything, any real long length 0:20:37.640 --> 0:20:39.600 of of something that's got lots of kinks, and then 0:20:40.640 --> 0:20:42.960 you can see all sorts of weird shapes. And also 0:20:43.040 --> 0:20:45.800 as you uncoil it, it can spring in ways that 0:20:45.880 --> 0:20:51.600 are terrifying. Uh So the DNA molecule ends up creating these, 0:20:51.680 --> 0:20:54.600 uh these other odd shapes that that the scientists were 0:20:54.640 --> 0:20:58.320 able to observe. Um it was kind of interesting how 0:20:58.359 --> 0:21:02.080 they did it. They used a method called cryo electron 0:21:02.160 --> 0:21:06.360 tomography uh to study the the actual shapes, and they 0:21:06.440 --> 0:21:09.480 observed all sorts of interesting ones, like figure eights or 0:21:09.920 --> 0:21:12.480 coiled so tightly that look like it was a rod, 0:21:12.520 --> 0:21:17.520 not even two separate strands anymore. Also, according to one 0:21:17.520 --> 0:21:22.200 of the scientists, some of them look like rackets or handcuffs. 0:21:22.240 --> 0:21:25.439 So maybe maybe if your molecules are being naughty in 0:21:25.560 --> 0:21:28.520 your cells nucleus, the DNA will just go ahead and 0:21:29.040 --> 0:21:31.080 slap the cuffs on. I don't know how that works 0:21:31.080 --> 0:21:34.240 at any rate. No clovers though, no clovers that I saw. 0:21:34.480 --> 0:21:37.160 I mean, it's entirely possible that it just was not 0:21:37.520 --> 0:21:42.000 included on the list. Probably probably horseshoes, though if you 0:21:42.119 --> 0:21:44.679 crossed a couple of pairs of handcuffs, you'd essentially have 0:21:44.720 --> 0:21:48.600 a clover. Yeah, I would allow for the possibility that 0:21:48.680 --> 0:21:51.080 a clover could in fact be one of the many 0:21:51.160 --> 0:21:55.080 shapes that DNA could take, but depending on the coiling. Uh. 0:21:55.119 --> 0:21:58.040 The important thing here, though, is that understanding the shape 0:21:58.080 --> 0:22:02.000 of the molecules can help doctors developed better medicines and 0:22:02.040 --> 0:22:06.280 scientists helped develop better medicines because the the drugs we take, 0:22:06.320 --> 0:22:09.439 typically what does It releases some molecules into our system, 0:22:09.720 --> 0:22:12.639 and those molecules are looking for other molecules of a 0:22:12.760 --> 0:22:16.280 specific shape. So knowing more about the shape of DNA 0:22:16.440 --> 0:22:21.080 can make more effective medicines that are specifically looking for 0:22:21.200 --> 0:22:24.360 those shapes. So it does have a practical application. It's 0:22:24.400 --> 0:22:28.280 not just the idea of we just want to learn more, although, 0:22:28.400 --> 0:22:30.399 as we say on the show all the time, that 0:22:30.720 --> 0:22:34.200 then itself is a worthy endeavor most of the time. Okay, 0:22:34.240 --> 0:22:37.280 how about one other really interesting fact about DNA. We 0:22:37.320 --> 0:22:40.720 mentioned earlier, how there was the discovery over time that 0:22:40.880 --> 0:22:44.320 DNA is the gene, that DNA is the molecule in 0:22:44.359 --> 0:22:48.320 the body that conveys genetic information from parent to offspring. 0:22:48.800 --> 0:22:52.000 But one of the weird facts that we're discovering we 0:22:52.040 --> 0:22:54.480 actually started discovering in the twentieth century, but that we're 0:22:54.560 --> 0:22:57.800 learning more about all the time. Is something called horizontal 0:22:58.000 --> 0:23:01.600 gene transfer, which is where you can get a gene 0:23:01.680 --> 0:23:06.399 in your genome that doesn't come from your parents. Doesn't 0:23:06.440 --> 0:23:09.800 happen very often with humans, happens all the time with 0:23:09.880 --> 0:23:15.240