Brave Genius

by Sean B. Carroll

  The challenge for Monod, Jacob, and Pardee was to come up with some way to determine whether genes were responsible for the production of intermediates, whether stable or unstable, that were necessary for protein synthesis. The basic experimental idea was to find out whether enzyme synthesis would continue in a cell after a transferred gene was somehow removed. If it stopped, then that would suggest that ribosomes could not keep churning out protein without the gene being present, and that would rule out the role of a stable intermediate. It would also support the idea that the intermediate between DNA and protein was unstable. The problem with testing these ideas was that there was no way to physically remove a gene once it was transferred.

  After he returned to the University of California–Berkeley, Pardee and his graduate student Monica Riley solved the problem by executing an ingenious but technically difficult experiment. The trick they employed in their experiment was to use radioactivity to destroy the transferred galactosidase (z+) gene after mating and then to see whether enzyme production continued.

  Riley grew the donor cells in a medium in which the only source of phosphorus was the radioactive form phosphorus-32 (denoted 32P). The donor cells’ DNA thus became highly radioactive. The cells were then mated with z– i– recipient cells. After allowing time for mating, the transfer of the radioactive z+ gene, and the start of enzyme synthesis, Riley interrupted the mating and froze the bacteria in a preservative. While metabolism stopped in the bacteria, radioactive decay of the 32P in their DNA continued. The emission of beta particles by the 32P shattered the bonds that held together the DNA of the transferred z+ gene. Over many days in the freezer, the transferred gene disintegrated.

  Riley then thawed out the mated cells and compared enzyme synthesis in them with control cells that had received a nonradioactive gene but had been otherwise treated similarly. She found that enzyme synthesis was in fact compromised in the bacteria in which the transferred gene had been inactivated. The results meant that the continued presence of the gene was required for protein synthesis; there was no stable intermediate.

  Two possibilities still remained: either there was no intermediate at all and DNA directly instructed the formation of proteins, which seemed unlikely since it was known that in cells with nuclei, such as animal cells, the DNA is located in the nucleus while protein synthesis takes place outside of it in the cytoplasm; or, more likely, the intermediate was unstable. Identifying that intermediate would open Crick’s black box.

  In mid-April, Jacob traveled to London for a microbiology meeting and then took a side trip up to Cambridge to talk with Francis Crick and Sydney Brenner, a South African geneticist who had moved to Cambridge, about the latest developments. On Good Friday afternoon, he and a handful of other visitors gathered in Brenner’s apartment at King’s College. To Jacob, it felt more like an examination than a discussion, with Crick leading the pack of inquisitors with rapid-fire questions and comments.

  Jacob knew, however, that he was in a position of strength: he had the data. He went over the operon model, which had only recently been published in French. Then he described the new experiments and results from Riley and Pardee. Jacob explained all of the care and controls built into the 32P gene-destruction experiment. Brenner and Crick knew that Pardee and the Pasteur group were superb experimentalists, but they were still impressed. When Jacob reported the results and the crucial interpretation—that there was no stable intermediate—Crick and Brenner immediately realized the significance of the experiment. “That’s when the penny dropped,” Crick later recalled.

  Brenner and Crick leaped to their feet and began to argue, back and forth or at the same time, and at such a speed that Jacob could not follow all of the exchanges. Several minutes passed before the gist of the battle became clear. Brenner, Crick, and most other molecular biologists had long been hung up on the idea of the stability of ribosomes and of ribosomal RNA. Ribosomes were stable structures, true, but the new experiments proved that information coming from the gene was not stable. Crick realized that ribosomes were merely machines for reading information coming from the gene; their RNA did not carry the actual genetic information, as many had believed.

  What was that information, then? In their frenzied reaction to Jacob’s data, Brenner and Crick recalled experiments by two American researchers at the Oak Ridge National Laboratory in Tennessee, Elliot Volkin and Lazarus Astrachan. It was work whose significance was not at all clear at the time it was published in 1956, but now it was a vital clue. Volkin and Astrachan had found that when a bacterial virus called the T2 bacteriophage infected E. coli cells, RNA was made whose composition matched that of the viral DNA and was very different from the composition of ribosomal RNA. Crick and Brenner realized that newly made viral RNA must contain the information coming from the genes of the viral DNA.

  Jacob’s “X” had to be an unstable RNA intermediate between DNA and protein.

  Jacob was a bit embarrassed. Why hadn’t he thought of the Astrachan and Volkin viral RNA when he came up with the idea of an unstable intermediate? It was a big clue that he, Monod, and Pardee had somehow overlooked. But that was the nature of the game of science—of having to make connections between seemingly unrelated observations. And it was not as if these connections were that obvious. After all, Crick and Brenner were in Copenhagen when Jacob proposed “X,” and nothing had clicked then. Now, seven months later, the puzzle pieces fit together.

  Jacob took satisfaction in how, until that afternoon, something that had been a mere abstraction was now materializing, how “once again, a creature of pure reason came to life.”

  “X” was materializing, but it was still a long way from being proven.

  That same evening, there was a party at Crick’s home. Brenner and Jacob were too revved up to socialize with the crowd, so they grabbed some beer and sandwiches and huddled in a corner to figure out the next steps that were needed to look for the unstable RNA intermediate. They soon discovered that they had each been invited separately to visit the California Institute of Technology that summer: Jacob had been invited by Max Delbrück, and Brenner by Matthew Meselson; the latter was a master at radioactively labeling and separating large biomolecules. Brenner and Jacob realized that at Caltech they would have exactly the tools and expertise available to help them chase down the evidence they sought: that newly synthesized RNA carried genetic information and then associated with preexisting ribosomes.

  They decided to team up at Caltech to do the experiments. Amid the noise and chaos of the party, Brenner wrote out reams of notes—page after page of diagrams and calculations to design the experiments. Jacob felt spoiled, for he now had a second brilliant scientific partner.

  The next step was to ask their hosts in Caltech for their help. Back in Paris, Jacob wrote to Meselson and spelled out the idea he proposed to test: “A possible model would be that no genetic information is contained in the RNA particles [the ribosomes], but that the gene sends to these particles RNA unstable molecules which act as message [emphasis added] to the particles, brings the genetic information to them for the synthesis of a particular protein … This hypothesis can be probably checked easily in bacteria infected with phage T2. I think that Sydney will write to you in detail about this.”

  Brenner also wrote to Meselson, and he asked his host to provide all of the radioactive labels and equipment they would need: “You know exactly what we will have to use.”

  PLAN E: THE CAMPING TRAILER

  As Jacob was planning his trip to California, Monod was finalizing the details of his mission to Hungary in mid-May. Ullmann wrote to him to say that they were excitedly awaiting his visit and that everyone in Budapest wanted to meet him. She told Monod that the police were still keeping a close eye on her and Erdös. She added, “I believe that your visit will not be long enough for us to do any experiments.” This was code that there would not be time to execute an escape.

  Nevertheless, after almost giving up due to all of the previous failures and
setbacks, Kövesi was crafting an entirely new plan, one that Monod could help set up during his visit. He described the new scheme to Monod, as well as his somewhat fragile state of mind, in a letter at the end of April.

  Kövesi explained that one of the jobs he had done was to repair a used twenty-two-foot-long British camping trailer. He realized that if he bought it using the funds Monod had provided, it could be used for smuggling Ullmann and Erdös. All he needed was a driver willing to take on the risks. After being cheated again and again by criminals in the previous attempts, he thought that he should find an honest worker who needed some money. He wrote:

  I talked to one of my new friends and he did not hesitate very long. His name is Helm, is about thirty-six, an automobil-mechanic-monteur … The operation is simple and there is not one misterious factor … The trailer has two si[n]gle beds and a double one, two rooms, a kitchen and a bath./ I havnt decided yet, wether I should build a hide place or two, or just use the room under the single beds./ Helm takes a one week vacation with his wife, two children, and mother in law to Yugoslavia and visits the Budapest Fair. He passes the border each time at early night when the children are already sleeping upon the two single beds. Of course the family knows nothing of the real zeal of the voyage …

  On the last evening, he sends his family sight-seeing gets our friends into their places, puts the children into bed, and is in four-five hours on Austrian soil.

  That is about it.

  We are in no hurry what so ever, we can wait quietly until the Helms get their visas etc. But it would be good if you could get down there as soon as possible—you see why.

  Please, let me know, if you have any ideas, or remarks and the exact date of your visit, and your possible arrival to Vienna.

  Monod immediately dashed off a note to Ullmann, telling her that he looked forward to visiting her and Erdös “so that we can discuss anew the experiments we are preparing.”

  In order to understand the operation in detail, and so that he could explain it to Ullmann and Erdös, Monod scheduled to fly first to Vienna to see Kövesi. He also planned to see Kövesi on his way home from Hungary in order to share any ideas or instructions that Ullmann and Erdös had for Kövesi.

  Before Monod left for Hungary, Madeleine Brunerie took the precaution of making a copy of his address book—without Kövesi’s and Ullmann’s entries—in case Monod was searched by the Hungarian authorities. He told Madeleine that if he had to extend his trip in order to work on arranging the escape, he would call her and ask her to inform Kövesi.

  There was one more important task to complete before he left—to wrap up their paper with Riley and Pardee that described the gene-destruction experiment and proposed an unstable intermediate between DNA and protein—the proposal that Jacob would soon dash off to California to test. The collaboration entailed many drafts of the manuscript being sent back and forth and much correspondence between Berkeley and Paris. Finally, after seven months of writing and rewriting, the paper was sent to the Journal of Molecular Biology.

  Late on the afternoon of Friday, May 13, with all of the arrangements made, Monod gathered his packed suitcase from his Pasteur office. In the hallway, all of the Pasteur staff who knew about the mission, including Lwoff, lined up to see him off.

  SIGHTSEEING IN BUDAPEST

  After seeing Kövesi in Vienna and going over the various parts of the operation, Monod flew to Budapest on May 14. He was to visit various institutes and the University of Szeged, to meet with scientists and students, and to give a lecture before the Hungarian Academy of Sciences.

  Ullmann and Erdös were to serve as Monod’s hosts for the entire visit, which would give them the opportunity to talk privately, to discuss every detail of the operation, and to scout possible locations around Budapest where Kövesi’s driver and the two would-be escapees might rendezvous.

  But talking without their conversations being overheard and surveying locations without arousing suspicion would not be easy. The first day in Budapest, Monod went to Ullmann and Erdös’s apartment. Once Monod started to talk candidly, Ullmann quickly put a pillow over the telephone, assuming that it was bugged.

  Monod understood her signal. He started to laugh and said, “Oh, let’s go and have a walk because there are such nice surroundings here.” It was like being in the Resistance again. The three conspirators went for a walk in a nearby park.

  Monod and Erdös had never met prior to Monod’s visit. The two men had an immediate rapport. Erdös was very impressed with Monod’s obvious intelligence and physical fitness. Monod found Erdös to be very calm, particularly under the circumstances of constantly facing the threat of imprisonment. Monod sounded Erdös out regarding his determination to escape. Erdös was emphatic that he wanted to get out of Hungary, even knowing that he faced life imprisonment if caught. At the time, Hungary’s borders were tightly sealed; no one was slipping out of the country.

  They next had to work out various details of the operation. One of the most important matters was to find a place where Ullmann and Erdös could meet Helm and get into their hiding places in the camping trailer without being seen. Monod could not rent a car, for there were none available in Hungary, so Ullmann arranged for a car and chauffeur from the Hungarian Academy. Monod told the chauffeur that he wanted to see the Danube. Under the guise of a sightseeing trip, Monod, Ullmann, and Erdös looked for good spots along the river for a clandestine rendezvous.

  The chauffeur could not understand Monod’s interest in the river. Monod kept asking to stop, saying, “Oh, I should like to have a look at this place.”

  The chauffeur kept telling Monod, “There is nothing here.”

  Monod replied, “I like rivers.”

  Along the shores of the Danube, there were many long stretches where there were no settlements, just trees and small clearings. It was important to find a well-concealed place that was close to a bus stop so that Ullmann and Erdös could get to it on their own. Monod selected one spot and pointed it out to Ullmann and Erdös. They got out of the car and memorized the kilometer marker on the stone.

  The chauffeur later remarked that he was impressed by the French professor’s love of nature.

  Erdös thought of more items for the operation checklist. One great concern was whether the border guards were likely to search the trailer. He suggested to Monod that Helm first make a test run to see how the guards reacted. Monod agreed and later passed the idea on to Kövesi, with the instruction that Helm should then go see Ullmann and Erdös to let them know how the test went.

  The official part of Monod’s visit to Hungary was a smashing success. In his lecture given in English before the Academy, it was the first time since 1948, in a country still under the influence of Lysenkoism, that the word “gene” was pronounced. Lysenko had continued to deny the role of DNA in heredity, even years after the discoveries of Watson and Crick. And very few scientists in Hungary were familiar with bacterial genetics, so Monod brought an entirely new perspective. Those in attendance said that they had never before heard a lecturer like Monod, who held the audience spellbound.

  Monod had several other official obligations. He had lunch with the French ambassador to Hungary, who cautioned him to be very careful when he spoke with Ullmann because she was certainly a spy of the Hungarian secret police! Monod found this hilarious and could not stop laughing when he later told the story to Ullmann.

  On his visit to the University of Szeged, Monod enjoyed a dinner with some colleagues, serenaded by an excellent Gypsy violinist. When Jacques learned that the musician could not read music, he asked whether he could play by just listening to whistling. The Gypsy said yes. Sure enough, after Monod whistled Mozart and Bach tunes, the violinist played them perfectly.

  AFTER STOPPING IN Vienna to convey the messages from Ullmann and Erdös to Kövesi, Monod returned to Paris on May 20.

  Monod wrote to Ullmann and Erdös in code to let them know that the operation with Kövesi and Helm was in motion: “Our extract
ions, in particular, appear to be progressing methodically and favorably. In this regard, Tom’s advice, drawn from his own experiments with myco-bacteria, will be of great help to us.”

  Monod wrote to Kövesi that he was transferring 50,000 Austrian schillings to his account to pay for the camping trailer and Helm’s fee. He also asked Kövesi to stay in close contact:

  I hardly need to tell you that I am constantly thinking about our plans and how they will work out. I will be grateful to you for any information you will find time to send me regarding the dates, the organization and especially the testing of the hiding places, and so on.

  The more I think about it, the more I feel that the two tests the trailer will go through at the two boarders [sic] is of the utmost importance. Helm should be instructed to let A. know precisely how it went so that they can make the decision by themselves whether to go ahead or not.

  The former Resistance officer was also concerned about maintaining secrecy:

  Also, may I mention again that leaks about some enterprise browing [sic] around Laubichler Garage [where Kövesi and Helm worked] may be most unlikely, but they represent a potentially very great danger. Helm must be made to understand that clearly.

  My love to you and Eva. I hope to God I will see all four [of you] pretty soon.

  TO AUSTRIA UNDER A BATHTUB

  In early June, Helm made a preliminary trip to Budapest and visited Ullmann’s institute in order to introduce himself. When he arrived, Ullmann was summoned to meet her German-speaking guest. Afraid that Helm would arouse suspicion among her colleagues, Ullmann had a handy alibi: she was teaching in German to first-year medical students from East Germany, so she explained that Helm’s visit was related to her teaching. Nevertheless, she wanted to get rid of Helm as quickly as she could.