The Birth of the Archaea: a Personal Retrospective Carl R. Woese Department of Microbiology ...

24 Pages·2006·0.16 MB·English

The Birth of the Archaea: a Personal Retrospective

Carl R. Woese
Department of Microbiology
University of Illinois
Urbana, Illinois 61801

Dedicated to Wolfram Zillig:
A founder of the archaeal revolution.

Mailing address: Department of Microbiology, University of Illinois, 601 South
Goodwin Ave., Urbana, IL 61801-3709. Phone [phone]. Fax (217) 244-
6697. E-mail [email protected].
Carl R. Woese

Let There Be Light
My job was to determine the complete
For me the moment was, I believe, the sequence of every oligonucleotide of
afternoon of June 11, 1976. I had just significant length (five or more
taped the film of a primary "Sanger nucleotides) in the primary pattern,
pattern" to a back-lit translucent "wall" in which required the aforementioned
the lab and had begun to "interpret" the "secondary" patterns. These in turn
pattern in terms of the "secondary cuts" were created by removing little snippets
taken from it, the corresponding films of of paper at the appropriate places in the
which were lying on a huge light table corresponding original
directly beneath the "primary"; the object electrophoretogram and further
being to infer the sequences of all the digesting the oligonucleotide(s) therein
oligonucleotides (of significant length) in (in situ) with one or a few ribonucleases
the primary pattern. Except for this of different cutting specificities than that
eerie lighting arrangement, the room of T1 RNAse (thereby creating sub-
was fairly dark, with the only prominent fragments). These enzymatically treated
features being the pattern of back-lit snippets were then individually
black spots on the "primary" film and the reinserted (mashed) into a very large
corresponding transluminated lines of sheet of (DEAE cellulose) paper (about
black "sub-cut" spots on the "secondary" 30 of them in a line near the "bottom" of
film lying below. such a sheet). Each large "secondary"
sheet was then subject to one
dimensional electrophoresis to resolve
The spots on the "primary" film the sub-fragments in each of the thirty-
represented specific oligonucleotide odd secondary digestions from one
fragments into which a (radio-labeled) another. From the one or several
16S rRNA (ribosomal RNA) had been "secondary" cuts taken from a primary
cut by T1 ribonuclease, then subjected spot, the exact sequence of the
to a two dimensional paper oligonucleotide(s) in the corresponding
electrophoretic separation, with the primary spot could (almost always) be
resulting oligonucleotide "spots" deduced (Uchida et al, 1974).
detected by means of X-ray film (Uchida
et al., 1974). The "isopleth" pattern on "Reading" a Sanger pattern in this
the film of the "Sanger pattern" (Sanger fashion was painstaking work, requiring
et al, 1965) already revealed a great a good fraction of the day to work up a
deal about the sequence(s) of the single "primary", something I at the time
oligonucleotide(s) in the individual spots; had been doing for several days a week
for instance, the length of oligo, number off and on for a long time. It was routine
of uracil residues it contained (a primary work, boring, but demanding full
determinant of the overall structure of concentration. [There were days when
the isopleth pattern), and the C I'd walk home from work saying to
(cytosine) vs. A (adenine) contents of myself: "Woese, you have destroyed
the individual spots in each in an your mind again today"]. But this day
isopleth (Sanger et al, 1965). [Each was special: I and Biology were in for a
oligonucleotide had but one G residue, surprise! First, however, more
at its 3' end, the cut site of ribonuclease background.
T1 (Sanger et al, 1965)].

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The Birth of the Archaea: a Personal Retrospective

Starting Down the Yellow Brick Road However, I differed from the whole lot of
them in perceiving the nature of the
I had had an abiding interest in the code as inseparable from the problem of
translation process since the latter part the nature and origin of the decoding
of the 1950s; first with the ribosome and mechanism. Thus, translation to me
its subunits, then, starting in 1960, with was the central biological concern. It
the genetic code ─ the hot topic of represented one of a new class of major
molecular biology at the time. The code evolutionary problems that molecular
had come into prominence on the heels probings of the cell were bringing to
of Watson and Crick's two world-shaking light. Now was the time to start thinking
1953 publications. The physicist about the evolution of the cell and its
George Gamow thought he could see macromolecular componentry. How this
"pockets" in the double stranded evolution occurred is almost as much a
structure of DNA, pockets of just the mystery today as it was four decades
right size and spacing to hold and ago. But one thing was certain from the
discriminate among amino acids, start: approaching these sorts of "deep"
suggesting the basis for a direct universal evolutionary problems would
templating mechanism upon which require a universal phylogenetic
translation could be based (Watson & framework within which to work
Crick, 1953; Gamow, 1954). effectively. Since no universal
phylogeny then existed ─ our
understanding of evolutionary
Then came a thrilling but brief period relationships being effectively confined
when a clique of physicists and to plants and animals ─ this meant
molecular biologists worked together taking on the rather large task of
and competed to see who would be first determining genealogical relationships
to derive the "code" from "first for the microbial world, the bacteria and
principles". The prospect of theoretically single-celled eukaryotes, which, as it
solving the genetic code, the "language turned out, meant determining the
of life", was so seductive that cameo missing 95% or more of the "tree of
appearances on the coding stage were life". A slight diversion in my research
made by Feynmann and Teller (no program would be necessary ─ a
doubt prompted by the charismatic diversion that lasted a good two
Gamow). The decoders soon split into decades!
two camps, however, those who, like A method for my madness. In 1965,
Gamow, believed that the basis of the on his way to developing nucleic acid
code lay in specific recognition of amino sequencing technology, Fred Sanger
acids by nucleic acids, and those who, had spun off an "oligonucleotide
like Francis Crick, believed it impossible cataloging" methodology (Sanger et al.,
that nucleic acids could recognize 1965). This procedure, applied to
anything except other nucleic ribosomal RNA (the small subunit rRNA
acids/nucleotides, which they did it turned out), was exactly what we
through base pairing (F. H. C. Crick, needed to determine genealogical
unpublished "Letter to the RNA Tie relationships across the entire breadth
Club; see Judson, 1996). When I of the phylogenetic spectrum. It was
belatedly entered the area, my intuition already apparent from DNA-rRNA
sided with Gamow. hybridization studies that the sequence
of a ribosomal RNA tended to be highly
conserved, probably to the point that
recognizable sequence similarity would
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Carl R. Woese

extend across the full taxonomic microbiologist's search for these
spectrum (Yankofsky & Spiegelman, relationships had gotten itself into.
1962). Ribosomal RNAs are obviously
ubiquitous; they occur in the cell in
thousands of copies; and they can be The best advice I'd solicited regarding
radio-labeled and isolated with relative organism choice came from my
ease. In addition, they are functionally colleague in the Microbiology
about as constant as one could wish for Department at Illinois, Ralph Wolfe. By
─ they are not adaptive characters. And now I'd gotten used to microbiologists
last but not least, rRNAs are integral suggesting that we work on their favorite
parts of a complex, integrated molecular bugs, and in this respect, Wolfe was no
aggregate (genetically dispersed within different. But what he had to say was;
the genome), which would make them his advice was more compelling than
as insensitive as can be to the any other I had received! I can almost
vicissitudes of reticulate evolution (Fox remember his words: he told me the
et al, 1977a). Only technological methanogens were united as a group by
problems seemed to stand in our way: a unique biochemistry that involved a
growing the various organisms and set of unusual coenzymes. Yet, the
doing so in a low phosphate, radioactive organisms showed no uniformity in their
medium; tweaking the Sanger method to morphologies, which latter fact had
fit our needs; finding needed help; and caused taxonomists initially to scatter
so on. Scientists do not want to, or them throughout the various taxa in the
often cannot, create all the things they 7th edition of Bergey's Manual (Breed et
need in their work. In our case the chief al, 1957). [In Bergey's 8th, however,
problem was the organisms required for they had all been grouped on the basis
the project. Half of them at least would of their common biochemistry (Murray et
be too fastidious for anyone but an al., 1974)]. Finally! here was the kind of
expert to grow. Striking up phylogenetic challenge I was hoping
collaborations with experts in the culture for. I longed to characterize a
of particular organisms was essential. methanogen rRNA as soon as possible.
But it wasn't possible ─ at least not yet.
Wolfe and I had spoken in early 1974 (if
Learning our way around. Coming I recall correctly), and the technology
into the game as a needed for growing and radio-labeling
biophysicist/molecular biologist my the methanogens safely was not at that
knowledge of bacteria and time in place. Now, back to the main
bacteriologists didn't extend far beyond thread.
E. coli, Bacillus, and Louis Pasteur; and
I didn't have the foggiest notion of how
bacteria were related to one another. It Epiphany!
was time to ask real microbiologists for
help in choosing the right organisms. By the beginning of 1976 my lab had
Each, of course, had a different opinion "cataloged" (generated T1
(the bacteria they themselves worked oligonucleotide lists) for roughly 30
with, that is). At that stage, I didn't know organisms, mainly "procaryotes" and a
that actually there were no experts on smattering of eukaryotes. It had
bacterial relationships (those above the become obvious that the two groups
level, say, of genus and occasionally could be readily distinguished from each
family, that is). And I was completely other on the basis of "oligonucleotide
unaware of the bizarre state that the signatures", which were lists of
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The Birth of the Archaea: a Personal Retrospective

oligonucleotides characteristic of one of syllable monstrosity that was always
the two groups to the exclusion of the shortened to "∆H", the organism's strain
other. The two apposing oligonucleotide designation (Zeikus & Wolfe, 1972).
signatures were remarkably distinct. [In
addition, a set of "universal"
oligonucleotides existed, those found in From the get-go ∆H's Sanger pattern
all the rRNA catalogs we had so far was strange. First of all the two small
generated]. In working up a Sanger "odd" oligos on the primary pattern that
pattern for an organism, one had only to screamed out "procaryote" were
"read" a small number of oligos into it absent. Intrigued by this appetizer, but
before being able to smile and say: "Oh, afraid to make too much of it, I quickly
that's a procaryote", or "that a euk". jumped into the "G isopleth"
There were two spots on the primary (oligonucleotides that lack a uracil
films of all procaryotic rRNAs that easily residue), hoping to find the first of the
caught one's eye, for they contained procaryotic signature oligos, which
modified nucleotides and, so, were would certainly set things back on the
located at places in the Sanger pattern procaryote track! Imagine my surprise
where normally there would be no when that "signature" oligo was missing
oligonucleotides. These "odd oligos" as well. Not only that, but the G-isopleth
allowed one to declare "procaryote" at contained the rather large 3' terminal
first glance: after that, it was just a oligonucleotide of this 16S rRNA, which
matter of detailing the rest of the pattern did not belong there! What was going
to figure out the relationship of the new on? This methanogen rRNA was not
procaryote to ones already cataloged. feeling procaryotic. The more oligos I
sequenced, the less procaryotic it felt,
as signature oligo after procaryotic
By 1976 Wolfe and his student Bill Balch signature oligo failed to turn up.
had developed a technique for growing However, a number of them were still
methanogens (in pressurized serum there, as, surprisingly, were some oligos
bottles) that was sterile, fast, and (most from the eukaryotic signature, and,
important from our point of view), safe thankfully, quite a few of the oligos we'd
enough to permit cells to be radio- considered universal in distribution.
labeled (Balch & Wolfe, 1976). George What was this RNA? It was not that of a
Fox, then my post-doc, had known Bill procaryote. It was not eukaryotic. Nor
from a course they'd taken together at was it from Mars (because of the
Woods Hole the summer before George "universals"). Then it dawned on me.
arrived at Illinois. Their acquaintance Was there something out there other
made it easy for George to approach Bill than procaryotes and eucaryotes ─
about a collaboration to work on perhaps a distant relative of their's that
methangens ─ which George did on his no one had realized was there? Why
own initiative ─ the year the Balch-Wolfe not? But the idea surely wasn't in
method was being published. It was on keeping with conventional wisdom!
that aforementioned day in June 1976
that I began to read the Sanger pattern
produced (by my technician Linda I rushed to share my out-of-biology
Magrum) from George and Bill's first experience with George, a skeptical
successful methanogen rRNA prep. George Fox to be sure. George was
The formal name of the organism was always skeptical. That's what made him
Methanobacterium a good scientist; and because of that,
thermoautotrophicum, a fourteen whatever skepticism he initially evinced
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Carl R. Woese

quickly dissipated. "Yes", he agreed, ribosomal RNA is a non-adaptive,
there probably was something else out universal character. That's what makes
there: it wasn't just procaryotes and its sequence so good for tracing
eukaryotes all the way down. That was organismal genealogies. It is also what
a heady thought, novel enough that we makes it completely uninformative as
sensed trouble in trying to convince regards the phenotypes of the
other biologists of the idea. Little did we organisms whose genealogies it traces.
know how much trouble there would be! Darwin had defined evolution as
descent with variation. In our case there
had been a long trail of descent, and,
A finding like this you do not therefore, we should find a comparably
immediately go out and shout about. huge amount of variation, not only
You had better have all your ducks in a quantitative but qualitative. In other
row and have firmer evidence than words, there had to be important
would otherwise be needed. We went features characteristic of our new
into fast-forward mode: by the end of the urkingdom that distinguished it sharply
year (1976) we had five additional from the rest of the living world, and
methanogen catalogs in hand, with there should be impressive variation
more on the way. They would cover all among the species in the urkingdom, as
the disparate morphologies associated well. Testing these two main
with the known methanogens. And sure evolutionary predictions drove our work
enough, none of the new catalogs was from that point on.
"procaryotic" (or eukaryotic): and they
were all of a kind! The methanogens
represented a new highest level There had already been a promising
taxonomic grouping, which could be sign in the biochemistry of the
defined by a characteristic methanogens. We now knew for sure
oligonucleotide signature. [And tellingly, that methanogenesis was indeed
that signature was no more extensive confined to a particular phylogenetically-
than were those of the "procaryotes" or defined group of organisms and that the
the eukaryotes, implying that within process utilized a set of co-enzymes
whatever new taxon they represented, that apparently were found no where
the methanogens were quite a highly else (Balch & Wolfe, 1979). Doubly
diverged group]. Darwin had long ago good! But with their highly specific,
said that there would come a day when restricted distribution these coenzymes
there would be "very fairly true were going to be of no use to us in
genealogical trees of each great searching for non-methanogenic
kingdom of nature." Perhaps that day members of our new urkingdom.
was at hand! In any case, there was
lots of work still to do.
The big question was then: where are
the predicted other phenotypes? How
Build It and They Will Come. could they be found? [As it turned out, a
couple of the sought-for non-
A new "urkingdom" (as we were methanogenic archaeal phenotypes lay
beginning to call our new highest level unknown on our "to-do" list.
phylogenetic group) would be a major Thermoplasma (which had been
evolutionary find. It afforded a rare described as a mycoplasma growing
opportunity to put the theory of evolution freely under hot and acid conditions)
to serious predictive test. As I've said, was among the mycoplasmas tabbed for
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The Birth of the Archaea: a Personal Retrospective

rRNA characterization in a collaboration peptidoglycan; and possession of
with Jack Maniloff (University of peptidoglycan-containing cell walls had
Rochester), a collaboration that had come to be considered one (of the few
begun in earnest in the spring of 1975 positive) unifying characteristics of
(with Mycoplasma gallisepticum). And procaryotes (Stanier et al, 1963). There
there were the extreme halophiles, had been no systematic examination of
whose unusual obligate high salt growth bacterial walls before about 1967,
conditions made them obvious although a fair number of them had
candidates for the phylogeny project in been characterized on a hit-or-miss
any case. I have often mused in recent basis. What Kandler had known (which
times about how the history of the we didn't) was that the walls of at least
archaea would have played out had one methanogen and those of some
their entrance into our world been extreme halophiles did not contain
through one of these other portals. No peptidoglycan (Kandler & Hippe, 1977).
doubt that things would have gone very
differently!
What did these atypical walls imply? On
Fortunately, the job of hunting for other the basis of the cell wall studies alone
phenotypes that might belong to the (the lack of peptidoglycan), one could
new urkingdom turned out to be easier not reliably infer much, especially infer
than I imagined. Unbeknownst to that the peptidoglycan-less organisms
George and me, our collaborator Ralph constituted a monophyletic grouping
Wolfe had invited the well-known unto themselves. [Bacteria atypical in
German microbiologist Otto Kandler to one way or another were often
Urbana for a visit. [Being a molecular encountered, and sometimes they
biologist, I had never heard of this lacked some property that
Kandler fellow ─ or almost any other microbiologists had come to believe was
well-known microbiologist, for that typical of "procaryotes". But in all such
matter ─ until the day that Ralph cases, the idiosyncrasy in question had
marched him into my office to hear the been passed off as adaptation to some
official word from George and myself unusual environment. It would require
about the new urkingdom]. According to much stronger evidence than one or two
his records, Otto (as I would soon come out-of-the-blue idiosyncrasies to make a
to call him) visited Urbana in January of microbiologist question a bacterium's
1977, well before publication of our procaryotic pedigree. And as we were
finding. soon to find out, there were some
among them who would not question
that pedigree even when confronted
The German Smiled. Amazingly, with strong evidence!]
Kandler ─ unlike the others we'd tried to
convince about what our findings meant
─ wasn't incredulous or disbelieving or Kandler had fully realized the potential
anything. I think he smiled. A "third significance of the cell wall studies in the
form of life" was fine with him; he had light of our rRNA molecular phylogenetic
almost expected it. For some time evidence, and had immediately gone
Kandler had, from his own work and that back to Germany intent upon fleshing
of others, known that the walls of certain out the comparative study of cell walls ─
procaryotes were highly atypical. The and to spread the word. But his visit
walls of the bacteria so far characterized had left us with a critical clue in our hunt
had (almost) all contained for novel archaebacterial phenotypes: if
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Carl R. Woese

unusual cell walls meant anything, of the cloning era (signaled by the
perhaps the extreme halophiles would recent cloning in bacteria of the gene for
turn out to be members of our new "far the growth hormone somatotrophin). At
out" group. We were desperate to get the time, no one could see that this
our hands on cultures of extreme fortuitous coincidence foretold the
halophiles. coming battle over biology's future, and
the coincident press releases were
With the help of Jane Gibson (Cornell) tantamount to the first skirmish in the
we obtained some halophile cultures ideological struggle that would pit the
from the Woods Hole collection. I was forces of what would become the
not about to wait for a student or a biomedical-industrial complex against
collaboration to come along to grow the those representing a resurgent
organisms. I donned my acid-eaten lab Darwinism. Our "third form of life", which
coat (which had hung on the back of my touched upon one of the deepest chords
office door for over a decade) and went in human nature (i.e., where we came
back to the bench. I grew the cultures from), completely wiped the press
myself, turning them over to one of my release announcing the era of "Man-the-
students, Kenneth Leuhrsen, for the medical-miracle" off the front pages of
more exacting extraction and isolation the papers. I was overjoyed at the
procedures for a radio-labeled 16S public's appreciation of our work (Fox et
rRNA; and Ken's prep would as always al, 1977b; Woese & Fox, 1977b)!
be given to our trusty Linda for Sanger
pattern production. By late spring of
1977, a year after we'd seen our first But there were already rumblings from
methanogen catalog, we were gazing at the scientific heights. On the day the
a 16S rRNA catalog from the first front page of The New York Times
extreme halophile. It didn't disappoint. announced our discovery of a "third form
Here was the first non-methanogenic of life", my colleague Ralph Wolfe
phenotype to join the group ─ and a received a telephone call from his friend,
novel phenotype it indeed was. But I'm the Nobel Laureate Salvador Luria
getting ahead of myself. It's time to see (whom he did not initially name), an
how the public ─ and the biology upset Salvador Luria. According to
establishment ─ reacted when this Wolfe, Luria told him in no uncertain
strange archaeal chimera was loosed terms to publicly dissociate himself from
upon their world. this scientific fakery or face the ruination
of his career. In a recent recounting of
the episode (Wolfe, 2001) Ralph said he
Confrontation and Heresy was so humiliated he "wanted to crawl
under something and hide"; but he
The press release concerning the "third managed to tell Luria that supporting
form of life" was set to coincide with the evidence for the claim had just been
publication of the first of our two papers published in the Proceedings of the
in the Proceedings of the U. S. National National Academy of Sciences (a fact
Academy of Sciences, November 3rd that had appeared in the New York
1977. A telling coincidence was to Times account). Luria begrudged that
occur. November 3rd just so happened he hadn't known about any publication,
to be the date chosen by the then but that the journal happened to be
president of the U.S. National Academy there on his desk. Fortunately, Ralph
of Sciences, Philip Handler, to release left for a planned family gathering out of
an official statement heralding the dawn
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The Birth of the Archaea: a Personal Retrospective

town the next day (Wolfe, 2001) and It was not simply the extreme halophiles
thereby escaped further humiliation. that had the strange lipids, either: Two
other recently isolated bacteria,
Thermoplasma acidophilum (Darland &
As you might expect, I saw the episode Brock, 1970) and Sulfolobus
and its overall significance differently. acidocaldarius (Brock et al, 1972) did as
How could this Luria fellow have the well (Langworthy et al, 1972; 1974).
temerity to excoriate his friend and my Thomas Brock, whose laboratory had
colleague like that? What pedestal was first isolated and characterized both
he standing on? It appears that he had organisms, had noted the lipid
blustered at Ralph something to the coincidence. And he later would say that
effect that: "Everybody knows that all the unusual lipids the two shared was a
bacteria are procaryotes; there can't be clear case of convergent evolution. In
any such thing as a 'third form of life'"! support of that assertion Brock would
Irony of ironies! As time (and the invoke the ether-linked lipids of the
diligence of a particular scientific extreme halophiles: "This hypothesis is
historian) have shown, the fakery lay not strengthened by the fact that
in our work, but in the prokaryote Halobacterium, another quite different
concept itself (Sapp, 2005): it is now organism, also has lipids similar to those
clear that the "procaryote" was mere of the two acidophilic thermophiles"
guesswork. [More on this below]. But in (Brock, 1978).
the hey-day of the procaryote, which this
was, the true believers were out to
pillory us for our heresy: how dare we Brock's argument doesn't make sense;
proclaim that the mighty at least today it doesn't. In its time,
PROCARYOTIC EMPEROR WASN'T however, it was reasonable. Like all
WEARING ANY CLOTHES! biologists of that period, Brock firmly
believed all bacteria to be
"procaryotes". If both of the
Expanding the Urkingdom thermophiles were procaryotes and they
were not specifically related (as was
With the halophiles came another clue ─ believed), then their common
lipids, highly unusual ether-linked, idiosyncrasy has to represent
branched chain lipids. In my whole convergence, independent adaptations
career I'd never paid attention to lipids, to their respective extreme niches.
and here we were with lipids on the From this perspective the case for
brain! The fact that extreme halophiles convergent evolution is indeed
possessed ether-linked lipids had been strengthened by pointing to a third
published in the mid-1960s (Kates et al, prokaryotic species (the extreme
1965; Kates, 1972), but nothing much halophiles), from a still different extreme
had been made of it: these strange niche, that also had similar strange
lipids seemed to be just one more lipids. Brock's conventional mind set
unexplainable biological idiosyncrasy. here is a wonderful example of what
Microbiologists and biochemists didn't comes of unquestioned acceptance of
view things evolutionarily. From a the assumption that all bacteria are
genuinely biological perspective, "procaryotes" ─ all idiosyncratic
however, these lipids were significant ─ characteristics then become adaptive
evolutionarily significant. changes.

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Carl R. Woese

We didn't know what kind of lipids the Tornabene (a colleague and oft-time
methanogens had, and that was critical, collaborator of Langworthy's). And in
for the lipids were a good candidate for short order there the answer was:
a property shared by all of the methanogens have ether-linked lipids
organisms in the new urkingdom. (Tornabene & Langworthy, 1979)! The
Determining the lipid type of the circle had been closed. The first
methanogens was essential. I archaebacterial-universal phenotypic
frequently discussed with Wolfe whom property had been found.
we could enlist to find the answer.
Although Brock wasn't the one to
approach, one of his colleagues, Tom Recently Tom L. recalled to me in
Langworthy at the University of South touching detail our first contact (he has
Dakota (an expert in lipid analysis), a photographic kind of memory). It was
seemed to me a good bet; and it was warm that day in mid-November 1977.
decided (I thought) to send cells to He had been eating lunch and reading
Langworthy. an article in the latest issue of Time
magazine about a "third form of life".
Since there had been no mention of our
Ralph then threw me a curve ball. He unpublished halophile work in the Time
had come up with a different candidate, article, Tom was unaware that we knew
a young Professor at Yale who was about any lipid connection. So, Tom
about to join our Microbiology faculty, had his own "eureka moment", for some
who was also an expert lipid chemist, of the bacteria he was working with,
name of John Cronan. Ralph felt Thermoplasma and Sulfolobus, were
(rightly, I had to admit) that it would be unusual enough in their properties that
more collegial for us to work with they might even represent a fourth
Cronan. So Ralph ordered a pellet of urkingdom; c.f. Brock quote above. He
methanogen cells sent off to John for was thinking of contacting Time
lipid analysis. Days went by; weeks magazine about the possibility, when
went by; it seemed like more; and no the phone rang. It was Woese calling to
word from Yale. Ralph finally agreed to ask him for help working with just these
call Cronan up and find out what had organisms. We had decided to grow
happened. It turns out that John's lab them ourselves and were seeking
had done a quick, but definitive, initial cultures from Tom, which he provided
screen of the methanogen for lipid type on the spot. I was not willing to wait for
upon receiving the prep and then Thermoplasma rRNA to come in under
dropped the project as uninteresting: the mycoplasma collaboration; it was at
there was nothing new there; the the bottom of Maniloff's list,
methanogen lipids were just like the
halophile lipids! John had perceived the
whole thing from a strictly biochemical The work on Thermoplasma went
perspective. Hadn't Ralph made clear smoothly, and by the beginning of 1978
to him how critical methanogen lipids there existed a catalog defining the 2nd
were to our case? major non-methanogenic archaeal
phenotype. I wanted to publish this one
in Nature, to give wide scientific
It was back to plan A. Bill Balch was coverage to the fact that archaebacteria
asked to prepare methanogens again, were now a real group (comprising at
and these were sent to Tom Langworthy least two diverse organismal
and another lipid biochemist, Thomas phenotypes). A manuscript had been
10