Abstract

Between about 1951 and the early 1960s, the basic structure of molecular biology was revealed. Central to our understanding was the unraveling of the various roles of RNA, culminating in the identification of messenger RNA (mRNA) and the deciphering of the genetic code. We know a great deal about the role of Brenner, Crick, Jacob, and Nirenberg in these discoveries, but many others played important supporting parts. One of these is a little-known scientist, Martynas Yčas, who appears in histories, generally without explanation, as the “archivist of the RNA Tie Club.” Yčas was born in Lithuania. His father helped write the Lithuanian Constitution in 1919. He studied Roman Law and served in the Lithuanian army before escaping from the Russians in 1940. The records of correspondence of Yčas with the physicist George Gamow and with Francis Crick throw some light on the genesis of our understanding of the role of mRNA. The story of the “RNA Tie Club” illustrates the difficulty in assigning credit for important discoveries and underscores the importance of a free exchange of information, even (or especially) among competitors.

The Effects of World War II and its Antecedent Years

Whatever the cause, the second World War saw the introduction of transformative technologies into biology. Radioactive isotopes became readily available. Less impressive, but no less important, technologies, such as column and paper chromatography, made it possible to achieve quantitative analyses of proteins, nucleic acids, and their components. More importantly, and for a variety of reasons, the war directed a new sort of scientist to study biological problems. Some were intrigued by Schrödinger’s arguments in his bookWhat is Life (Schrödinger 1946), and, at the same time, were looking for an intellectual challenging field that did not have military implications. But there were other sources of new talent. A major one was one of the greater pieces of social legislation in the United States: the GI Bill of Rights. This law provided a path to a college education for numerous individuals who otherwise would not have thought such a pathway possible. In addition, the influx of new students provided a financial stimulus to Colleges and Universities just emerging from the Depression years.

A second source of new talent was a group of young and not-so-young scientists who migrated to the United States to escape the dictatorships of Europe. The migration from Nazi Germany is well documented (Medawar and Pyke 2000). The migration from revolutionary Russia not so much, perhaps because it lasted longer; Boris Ephrussi, a pioneer in mammalian cell genetics, for example, left in 1920. My story includes two scientists, one relatively well known, George Gamow, and a second, Martynas Yčas, a displaced Lithuanian, both of whom, I contend, were serious participants in the effort to understand the genetic code and the mechanism by which information traveled from the gene to the protein-synthesizing machinery. Others made the final steps but Gamow and Yčas were important contributors to the environment that made their discoveries possible. Gamow is perhaps best known for being the father (or at least one of the uncles) of the “Big Bang” theory in cosmology (Segre’ 2011). Yčas is often mentioned in histories of this period but mostly in passing without any identification (Cobb 2015).Crick (1988) mentions Yčas, but without any identification or elaboration as to his role. I knew him as a fellow graduate student, and afterward when we were both on faculties in Syracuse. His role is interesting since it illustrates how close some of the minor players may be to a major discovery. It also illustrates how a series of discoveries can be suddenly put together to clarify a whole series of phenomena. The background work is essential, but it is simpler to ascribe the final result to one, or a very few, individual(s).

Martynas Yčas

Martynas came from a well-educated, upper class, Lithuanian family. His father (Martynas Sr.) was a lawyer who had been elected to the Russian Duma, even though committed to the cause of Lithuanian independence. His mother Hypatia was an American citizen from Scranton Pennsylvania whose father had been an agitator for Lithuanian independence. Martynas Sr. met her (according to one of the Yčas family) during a round-the world-tour. The result was that Martynas and three younger sisters grew up bilingual (Yčas 2005). Martynas’ father participated in the 1919 Peace Conference as a Lithuanian delegate and was Lithuanian Finance Minister during the 1920s. This was clearly an upper-class family as indicated by the following personal experience. During the 1960s I had invited Martynas to give a seminar at The University of Chicago. Mrs. Musteikas, one of our laboratory technicians of Lithuanian ancestry saw the seminar notice and asked to meet him. She curtsied on being introduced! Not a usual response to visiting speakers! Yčas had studied law in Lithuania, but that was ended by the Russian occupation, and he had served as a cadet in the Lithuanian artillery. On confiscation of their family estate by the Russians in 1940, the whole family managed to escape across the border, through East Prussia to Berlin. They then traveled through Europe to Portugal, managed to get to Rio de Janeiro and then, after a short stay, during which Martynas senior died, to New York. That all this happened during a period of war in Europe is certainly due to some special circumstances. First, Hypatia Yčas was (or had been) a US citizen. Second, her daughter, also Hypatia, was a friend of the von Richthofen family (Baron von Richthofen was the Red Baron, the WWI flying “ace”) and Barbara von Richthofen was able to provide both food in Berlin and financial help for their travels.

The ship from Rio to New York stopped in Trinidad (Yčas 2005), which provides some support for a story Martynas told. He had a puckish sense of humor and may have been testing my reaction, but after reading Hypatia’s book the story makes sense. She records a brief stop in Trinidad (Yčas 2005) on their way to the United States. There is also a vague remembrance by John Yčas of a story his father told about Intelligence officers. A British intelligence officer was interviewing passengers (I deduce that it had to be at this Trinidad stop) and asked for evidence of good character. Martynas, according to his story, produced a document from the Gestapo testifying to the required good reputation. I’m sure he did it with a flourish. This bravado was certainly in character, but I’ll bet would never have worked with a US officer. Martynas came to this country in 1941, and, in 1944, enlisted in the US Army. Because of his Lithuanian training he was assigned to the Artillery. To quote from one of his sons: he was transferred to Army intelligence and when it was discovered he was proficient in Latin; it was concluded that he would therefore have no difficulty in learning Japanese! Shortly before starting Japanese, he contracted either mumps or some other infection that incapacitated him long enough to miss the start of the course. The next available course was Russian, so the Army assigned him to the Russian Language school at the University of Wisconsin. He met his wife Mary (a microbiologist) at a United Service Organization (USO) dance in Madison, and, after his discharge, earned a Bachelor of Science degree from Wisconsin and turned up at Caltech as a graduate student.

George Gamow is the subject of a joint biography with Max Delbrück (Segre’ 2011), which makes some sense since they were both acolytes of the physicist Niels Bohr in Copenhagen. By 1932, Gamow had become disillusioned with the Soviet regime and, in 1933, escaped with his wife via a scientific conference in Brussels. According to Segre’, Madam Curie was also part of this escape, but that story is found in Segre’s book. Gamow established himself in the United States, first at George Washington University. He was known for the brilliance of his ideas, a small but very significant fraction of which turned out to be correct, his hard drinking, and, most importantly, the good humor with which he took being proved wrong. He also had a rather impish sense of humor: he and a graduate student Ralph Alpher had an important idea about the origin of the elements in the Universe. Gamow decided that a paper on this subject required a proper set of authors so, apparently without permission, he added Hans Bethe to produce a paper authored by Alpher, Bethe and Gamow [the alpha, beta, gamma paper] (Alpheret al. 1948;Segre’ 2011). This rather light-hearted approach to science shows up in his invention of the “RNA Tie Club.”

In 1953, Watson and Crick published their model of a DNA structure (Watson and Crick 1953a,b). By this time, the work of Beadle and others had made it clear that there was some direct relationship between genes, which were now known to be made of DNA, and enzymes, which were proteins made of amino acids. Gamow read this paper and recognized that there had to be some relationship between the four nucleotide bases of DNA and the ∼20 amino acids in proteins (the absolute number of amino acids in proteins was still not certain). He was able to construct a model in which specific amino acids would fit into the “holes” in the DNA structure. Most importantly, he suggested a test of his hypothesis “there must be a partial correlation between adjacent amino acids” (Gamow 1954).

Yčas himself tells the story of what happened next in his introduction to the papers related to his work, deposited in the Archives of the University of Colorado Library:

I noted that in Gamow’s scheme his codons overlapped which would produce constraints on which amino acids could neighbor each other and that it should be possible to decode the codon-amino acid relations by a simple cryptographic approach… I was able to show that Gamow’s codon amino acid relations were not compatible with known amino acid sequences …I was at that time not personally acquainted with George Gamow but I informed him of my results. He was interested so we met at Woods Hole (oceanographic institute) in 1954 and continued a fruitful collaboration, including the publication of a book, virtually until the time he died (Yčas 2010).

At this time Yčas was 4 years from his PhD and working at the US Army Quartermaster Corps Research & Development Laboratories.

… After a while, Gamow formed a partly humorous “RNA Tie Club” to be confined to 20 members (representing the 20 kinds of amino acids found in proteins) who, he hoped would continue work on the coding problem. Most of the few who did were physicists. Biochemists, especially those with Nobel prizes tried to be polite, but usually made it clear that they regarded “decoding” as a theoretical approach and thus not real science. I (Yčas) continued work on the problem and was awarded the title of “archivist” of the club… (Yčas 2010).

The “Officers” of the Club, according to the letterhead Gamow had printed included George Gamow, Synthesiser; Jim Watson, Optimist; Francis Crick, Pessimist; Martynas Yčas, Archivist; Alex Rich, Lord Privy Seal.

It was evident to the members of the club that the sequence of nucleotides in the DNA in some way determined the sequence of the amino acids in protein. Their goal was twofold: to deduce the details of the “code” that related nucleotides and amino acids, and to determine how the information was transported. A detailed description of the various attempts to deduce the details of the code is found inWho Wrote the Book of Life? (Kay 2000).

The Search for mRNA

There was a good deal of information available by the mid-to-late 1950s to indicate that (most) protein synthesis occurred in the cytoplasm, even though (almost) all of the DNA was in the nucleus. Much of this information had been obtained by biochemists, but there was also a fascinating series of experiments using a large green alga,Acetabularia, which demonstrated clearly that there was a message produced in the nucleus that gave instructions for development to the cytoplasm, that this message was “used up” in the course of development, and needed a nucleus for replenishment (Hämmerling 1953). The experiments were well enough known that I could write:

The easiest interpretation of this type of experiment is that the nucleus produces some substance essential in differentiation which is stored in the cytoplasm and which is used up during the differentiation-regeneration process. …The nucleus does not have to divide to produce this material. The experiments therefore indicate that the nucleus is continually active (Strauss 1960).

The term “message” can be found in several publications of the period. The evidence was sufficient to permit Crick to formulate a set of rules about the transfer of information, the so-called “Central Dogma.” Although I know of no published comments, it has always seemed to me that Cricks terminology is a practical joke that escaped and developed a life of its own. “Dogma” is defined as “a principle or set of principles laid down by an authority as incontrovertibly true:e.g.the rejection of political dogma,the Christian dogma of the Trinity.” That Crick, a confirmed and somewhat aggressive atheist, should have accidentally picked on a term usually employed to refer to religious doctrine is beyond belief. I suggest he used it playfully and was then surprised at how it stuck.

Crick’s insight was that information proceeded from DNA to RNA to protein but never in the reverse direction. The question was just what was the nature of this message? Biochemical analysis had located the site of protein synthesis in small particles called ribosomes and a reasonable hypothesis as to their function was analogous to the one gene one enzyme hypothesis: “one ribosome one protein,” that is, each ribosomal particle should be specific for one specific protein. This hypothesis permitted some specific predictions. Since proteins vary in amino acid composition and sequence, and amino acid composition and sequence was determined by the nucleotide composition and sequence, ribosomes should also vary in nucleotide composition. Although it was not possible to analyze the RNA composition of single ribosomes, their overall bulk RNA composition should reflect the overall DNA composition, assuming (as was then supposed) that all the DNA was coding DNA. Surprisingly, this was not the case; ribosomes in general seemed to have very similar base compositions not at all related to the DNA composition. There was also a known problem. Two investigators at the Oak Ridge National Laboratories, Elliot Volkin and Lazarus Astrachan, had pointed out that, although mature bacteriophage contained no RNA, infectedEscherichia coli incorporated radioactive phosphorus into RNA nucleotides in proportions reminiscent of the composition of phage DNA. Their results, published in 1956 (Volkin and Astrachan 1956), were [according toBrenner (2005)] widely known in the molecular biology community but no one knew what to make of them. As judged from his reminiscences (Volkin 2001), Volkin’s interests did not extend to the coding problem or to the nature of information transfer.

By this time, Martynas had moved from the Quartermaster Corps laboratories to the Department of Microbiology at Syracuse University Medical School. I was on the faculty of the Liberal Arts College at Syracuse, and our families renewed their acquaintance. Martynas would come over to my laboratory to tell me what he was doing, but I confess to either not being too interested or to just not understanding. However, it was clear that he had thought of an ingenious biological way to test the idea that ribosomes were specific for the synthesis of particular proteins. A silkworm found in Nigeria,Epanaphe maloneyi, produces a silk fibroin of simple composition: mainly glycine and alanine. A second protein, sericin, of more complex constitution is produced in an anatomically separate portion of the gland. Yčas proposed collecting these insects at the time of maximum silk production and comparing the RNA composition of the fibroin producing cells with that of the sericin producers as well as with other portions of the insect. If the bulk RNA (that is mostly the ribosomes) determined protein specificity there should be a difference in the overall RNA composition. He persuaded the Lalor Foundation to award him a grant to collect the caterpillars, and, in 1957, set off for Nigeria.

No differences between the RNA from the fibroin-producing tissue and the bulk RNA of other tissues or from the sericin-producing portions were detected (Yčas and Vincent 1960a). Although I had no idea what this might have meant, in retrospect it was evidence (to Martynas at least) that the bulk RNA (i.e., ribosomes) did not determine protein specificity!

It should not be thought that the collection was onerous. The caterpillars were collected on the grounds of University College, Ibadan, Nigeria. In a letter to Gamow on December 3, 1957, Yčas wrote: “Life of course was pretty rigorous being in a house with two servants and a gardener, air conditioning, Hi-Fi and a car… Being exhausted by the hardships of the African bush, I flew back via Casablanca where I got a car and took off for a weeks’ vacation in Marakesh.”

It was at this point that Martynas teamed up with an embryologist, Walt Vincent, who had the ability to separate nucleotides. They then essentially repeated the Volkin-Astrachan experiment, but this time with yeast, and, as opposed to the previous workers, with a real interest in the relationship between RNA and protein. Their results with yeast indicated a fast turning over fraction of RNA with a composition reminiscent of yeast DNA and differing from that of the bulk RNA. They concluded:

The function of such an RNA is not clear. In view of its composition it might be a primary gene product acting as an agent for transmission of genetic information from DNA to protein. Alternatively it could be storing information for the replication of DNA itself if such a process is, as has been suggested, of an indirect nature (Yčas and Vincent 1960b).

As a result of his association with Gamow, and the very informal “RNA Tie Club,” Martynas was in correspondence with Crick about these results, all of which came about at a critical time for the understanding of mRNA. The events of the period have been described elsewhere (Cobb 2015), but, briefly, an experiment done at the Pasteur Institute (Pardeeet al. 1959) had shown that, upon entry of a critical gene intoE. coli, synthesis of the enzyme β-galactosidase started immediately at almost a maximum rate, and without the time lag that would have been expected were massive ribosomal RNA synthesis required. In his memoir (Crick 1988), Francis Crick recalls a meeting discussing this experiment with François Jacob in Cambridge on Good Friday, 1960 which happens to have been April 15. “Exactly what happened then is obscure… At this point Sidney Brenner let out a loud yelp—he had seen the answer….” This was mRNA—the rapidly turning over fraction reported by Volkin and Astrachan.

On that same day, April 15, 1960, Martynas wrote a letter to Crick: “Thank you very much for the note you and Brenner sent me. It was interesting to read your speculations as to the DNA like structure of S_rna. It makes me feel rather bad that I have omitted to send you the information we have on the subject. Unfortunately, I am short of copies of the manuscript and this paper is in press in theProceedings of the National Academy. However, I feel you should have some advance notice on the subject. The gist of the matter is that after brief exposure to³²P extracted yeast RNA has total counts in the 3′nucleotides which indicate a composition very close to that of yeast DNA…”

Martynas sent a preprint of his PNAS paper (Yčas and Vincent 1960b) and Crick responded in a letter dated May 9, 1960.

It is really very kind of you to send a copy of your paper so promptly… Sydney (Brenner) and I are now in two minds about writing a review, because our ideas, though somewhat novel to us, are really not original. We derived them a few days before your letter arrived, but in fact, with one reservation, they are just the same as one of the two you put forward. Moreover Belozersky also suggested something similar. As we may not write our review, I summarize our hypothesis here. It has three features;

Most of the RNA of ribosomes is not genetic RNA. Genetic RNA may be only, say, 10% of ribosomal RNA.

Genetic RNA has the same base-ratios as the DNA.

Genetic RNA is (at least under some circumstances) unstable.

By genetic RNA we mean the hypothetical RNA which carries the sequence information from gene to ribosomes.

You will see now how excited we were to receive your letter… As you will see this hypothesis explains a lot of things (including your silk-gland result)… (Yčas and Vincent 1960a).

It seems clear from this exchange that Crick, and, by extension, Brenner, knew of and appreciated the importance of Yčas’ results, which added nicely to their own work, even though there is no mention of the exchange in Crick’s memoir nor was Yčas’ contribution cited in the papers on the isolation of mRNA. Who to cite is partly a matter of taste; I suspect it is a rare investigator who has not at some point been surprised to find his work missing from a list of citations. As well documented byCobb (2015), one of the reasons no prize could be awarded for the discovery of mRNA is that there were too many plausible candidates.

The actual isolation of mRNA followed, and much of the excitement of the 1961 Cold Spring Harbor Symposium was a result of the experiments from a number of laboratories providing real evidence for the concept. The idea of instability of the message seems to have taken on an almost mystical importance. At the presentation at the Cold Spring Harbor Symposium in 1961, I commented in the question period that mRNA could not always be unstable because non-nucleated mammalian reticulocytes continued to synthesize hemoglobin. Those were the days when questions were published. Toward the end of the Symposium I was approached, I think by some post-doc from one of the presenting laboratories, who asked whether I really didn’t want to withdraw the question to avoid appearing too silly in print.

At almost the same time, and from a completely different source, was the completely unexpected and electrifying discovery by Nirenberg and Matthei that a synthetic polymer of polyuridine could direct the incorporation of phenylalanine into protein (Nirenberg and Matthaei 1961). Their discovery suggested a direct biochemical approach to the nature of the code, and, after a period of intense competition, the complete code was known by about 1966. The intensity of the competition among a few laboratories is illustrated by the following anecdote. I was present at a Gordon Conference during this period and Joe Speyer from Severo Ochoa’s laboratory was giving a talk. When asked about some details of his experimental procedures he replied, to accompanying boos and catcalls, that he couldn’t say. In the days before cell phones, there was one pay phone available in the auditorium and, during intermission, the hapless Speyer was seen in that booth. After intermission he announced that he could now give the details!

Yčas interest in the theoretical aspects of the coding problem continued and he published a book on the subject in 1969 (Yčas 1969). The book includes a perfectly fair and orthodox discussion of the discovery of mRNA and there is no evidence either in the book, or in my recollections, of his feeling unfairly treated. Gamow had just died, and the book,The Biological Code, is dedicated “To the memory of George Gamow, who introduced biological coding to biologists.” Martynas had coauthoredMr. Tompkins Inside Himself with Gamow just 2 years earlier (Gamow and Yčas 1967). It is clear that their relationship was central to Martynas’ work.

Nirenberg’s discovery only illustrated the central role of wet-lab biochemistry in the development of molecular biology. My guess is that wasn’t Martynas’ strong point. The analyses of RNA were all done with Walt Vincent—a colleague at Syracuse whose subsequent publication record indicates an interest in RNA/DNA relations in development. Martynas continued to publish theoretical papers on the evolution of the genetic code at least until 1999 (Yčas 1999). However, his attention had moved to the problem of consciousness, and, toward the end of his life, he resumed his correspondence with Crick. In April 1996, in answer to an offer to translate Crick’s book into Lithuanian, Crick wrote “I don’t think we shall fully understand consciousness by the end of this century, but it’s possible we can get a glimpse of the answer by then. Whether it will all fall into place, as molecular biology did, without a vital force, or whether we need a radical formulation, only time will tell. Best wishes, Yours, Francis P.S. By the way, I’ve not been knighted.”

I last saw Martynas in 2004 shortly after Crick’s death. He and Mary, his wife, were in retirement in Syracuse. At that time he was immersed in writing a biography of his father, which I understand has been published (in Lithuanian). Yčas had continued his correspondence with Crick about the nature of consciousness. It seemed to me that he was somewhat miffed that Crick had died before responding to his (Martynas’) latest insights.

I’ve wanted to tell Martynas’ story ever since I read those mysterious references to the “Archivist” of the RNA Tie Club. He was not in any way ill-treated, and perhaps one of the reasons he is not better known is found in a letter to Crick in which he states that he is “allergic to symposia and meetings” as an explanation for not attending a 1960 Gordon Conference. He was not one of the attendees of the 1961 Cold Spring Harbor Symposium (of course neither was Marshall Nirenberg). Two things about his career have always intrigued me. I feel almost embarrassed about the first because in our present environment it seems so idealistic. The way in which a newly minted PhD (in embryology!) with no credentials other than a keenly analytic intellect could form a collaboration with a noted astrophysicist and enter into a collaboration and competition with the group creating a new science has always seemed to me to be a model of how science is supposed to be conducted. The second is personally even stranger. That a young man from the Bronx should become a personal friend of a Lithuanian aristocrat is just improbable. It has been pointed out to me that once we were both graduate students at Caltech this wasn’t at all improbable but consider the events that brought us to the same place. The same set of events brought Gamow and other scientists to this country, helping to invigorate American science.

Martynas died in 2014 at the age of 96. A last anecdote: Martynas and I were gossiping about science one day in Syracuse during a family visit and our conversation turned to someone’s work. Martynas stopped. “One doesn’t judge one’s friends.”

Acknowledgments

John and Joe Yčas, Martynas’ sons, provided useful family background. I thank the archivists at the University of Colorado library for sifting through the Gamow/Yčas papers for relevant documents.

Footnotes

Literature Cited