Anecdotal, Historical and Critical Commentaries on Genetics
Edited by James F. Crow and William F. Dove
EDWARD Novitski, 1918–2006, was the acknowledged master of that special art of manipulating chromosomes during what Lucchesi (1994) called “the age of Drosophila chromosome mechanics.” Following the Sturtevant tradition, his guiding principle was to derive as much information as possible from breeding experiments with minimum use of direct cytological examination. Nobody could perform this kind of chromosome manipulation as well as Ed and he relished new challenges. (Novitski's closest friends and relatives, especially in later years, called him Eddie, a name he seems to have preferred. Those, such as ourselves, whose acquaintance extends over many years, knew him as Ed, which we shall adopt here.) He continued this kind of work long after the development of microbial and molecular genetics had carried the field in new directions.
Another side of Novitski was a love of pranks and practical jokes, which were indeed clever, sometimes diabolically so. He reached what must be the pinnacle of achievement in this rarified atmosphere, for his reputation was such that pranks that he never carried out were attributed to him nonetheless. He admired Richard Feynman, a physics genius who also enjoyed such things as safe cracking, bongo drums, and practical jokes. Both men took great pleasure in “finding things out” and shared highly creative minds and a love of pranks.
Fortunately, Ed completed an autobiographical memoir not long before his death (Novitski 2005). He was unusual; so, naturally, the book is unusual. It has four main sections. The first is “Fun and Games,” a series of anecdotes and practical jokes. The first prank is his most famous, perpetrated on Herschel Roman. Ed manipulated the seminar clock to run slowly so that Herschel, after finishing his talk, seemed to have an embarrassingly long period of time remaining to be filled. His attempts to extricate himself make an amusing story. The second part of Ed's book is the story of his own life. The third is his account of the rift between Alfred Sturtevant and Theodosius Dobzhansky. Novitski had the unique vantage point of having been successively a student of each of them, and he is clearly in Sturtevant's corner. The fourth part is titled “The Pleasure of Finding Things Out.” It recounts some of his most interesting intellectual challenges. The book is as idiosyncratic as Ed himself, a mixture of deep science, anecdotes, intellectual depth, and whimsy.
A BRIEF BIOGRAPHY
Edward Novitski was born in Wilkes-Barre, Pennsylvania, on July 24, 1918. He had an early interest in science, leading him to chemistry experiments and building a radio receiver. He also had an interest in collecting animals, especially snakes, a practice he engaged in after slipping out of highly unpleasant church services. Significantly for both their later careers, he and E. B. Lewis attended the same high school and were the leaders of a biology club. One day, while perusing the journal Science, Ed Lewis noticed an ad for Drosophila cultures, so most of the club's small treasury was used to get some stocks. It was the beginning of two illustrious Drosophila careers. Novitski carried on a correspondence with the Purdue faculty member S. A. Rifenburgh, who had furnished the flies for the biological supply house. With Rifenburgh's help, he got a scholarship to Purdue, without which college would have been unattainable for him.
While in high school Ed discovered a mutation, heldout (Novitski and Rifenburgh 1938), shown to be an allele of a gene that was subsequently named decapentaplegic. This is a key regulatory gene in dorsal–ventral patterning of the embryo. He also found the mutation, later called asteroid, which he sent to Ed Lewis; this mutation marked the beginning of Lewis's famed career (Crow and Bender 2004). Novitski carried on an extensive correspondence with C. B. Bridges, remarkable for the interest and professional respect that Bridges showed for this promising unknown scientist. No fewer than 36 letters were exchanged.
In high school, Ed learned Latin over the summer and entered the second-year class in the fall. At Purdue he soon discovered that he could get credit for college courses simply by learning the material on his own and taking examinations. In this way, starting with calculus, he completed his undergraduate studies at Purdue in 2 years. He influenced his friend Lewis to adopt the same strategy.
At Bridges' suggestion, he applied to and was accepted by Caltech, entering graduate school in the fall of 1938. Alas, Bridges was terminally ill at this time, so what might have been an important scientific collaboration never materialized. Novitski began graduate work as a student of Dobzhansky, irradiating Drosophila pseudoobscura to produce inversions and using these to isolate lethal mutations from natural populations. These lethals were to be tested for allelism, a heroic task since the number of tests goes up with the square of the number of mutations. Ed soon became disillusioned, thinking that the data had minimal value for distinguishing among alternative ideas and that the work could, as he said, be carried out as easily by a well-trained chimpanzee. He finally gave up, destroyed the stocks, and was promptly sacked as a teaching assistant.
After some uncertainty, he was finally awarded a fellowship with Sturtevant. He was now on the path that he would follow the rest of his life. Together they published an article showing the chromosomal homologies of various Drosophila species, as evidenced by the location of corresponding mutations (Sturtevant and Novitski 1941). This article uncovered an error by Dobzhansky, a failure to identify one chromosome arm. During this period and later, Novitski became increasingly conscious of numerous Dobzhansky errors. Another example is the “sex ratio” phenomenon, which Dobzhansky had interpreted as an extra chromosome replication. This was later shown to involve no unusual processes; rather, it involved the nonfunctioning of some meiotic products (Novitski et al. 1965). Novitski's disillusionment with Dobzhansky and his admiration of Sturtevant argues that, although the differences were always underplayed, he must have received considerable satisfaction from discovering the errors, as was probably true of Sturtevant as well.
Novitski received his Ph.D. in 1942. While in Dobzhansky's group, he met Esther Rudkin whom he later married while he was in military service. His service in the Army Air Force lasted 3 years, from 1942 to 1945. During this time the Air Force received a new, state of the art device, which was installed in bombers flying out of England. It failed to function as described, but characteristically Ed was able to identify the problem and restore its function. For this, he received a commendation from his commanding officer. After his discharge from the Air Force, he spent 2 years in the laboratory of Curt Stern at the University of Rochester, the first as a Guggenheim fellow and the second on an Atomic Energy project. Then came a year at the University of Missouri in the laboratory of A. B. Griffen and 2 years at Caltech, again with Sturtevant. In 1951 he joined the faculty at the University of Missouri where he stayed until 1956. He then moved to the Biology Division of the Oak Ridge National Laboratory as head of the Drosophila genetics group. Finally, in 1958, he became Professor of Biology at the University of Oregon where, except for sojourns in Zurich, Canberra, and Leiden, he remained until his retirement in 1983. He died June 29, 2006, in his 88th year.
A central theme in Novitski's work was the remaking of the Drosophila genome by attaching chromosome arms in novel ways. Attached X chromosomes were well known, but there were five other ways in which two X chromosomes could be attached to a single centromere. Ed succeeded in constructing all five (Novitski 1954a). These chromosomes were used to analyze various aspects of segregation and recombination. A particularly neat procedure was employed to join the X and Y. Attaching parts of the X to parts of the Y had already been done, but Novitski and Dan Lindsley succeeded, by a procedure that was both logical and ingenious, in attaching the entire X and Y chromosomes (Lindsley and Novitski 1950, 1963; for a nontechnical description, see Novitski 2005, pp. 145–148). The experiment was contrived so that only the desired type of male would have all the necessary Y chromosome fertility genes, so the presence of a single fertile male in a culture bottle would produce larvae—a labor-saving selective scheme worthy of the needle-in-the-haystack experiments of microbial geneticists. This chromosome became essential for all subsequent studies of the Y chromosome. Novitski also produced, by judicious combination of recombinant types, a compound XY chromosome that was a ring (Novitski and Childress 1976). Other constructions of note include assembly of the right and left autosomal arms in tandem with the centromere at the terminus. By the equivalent of a centromere fusion these acrocentric chromosomes could be doubled to produce an attached two and attached three. Finally, the tour de force: he was able to attach all four arms of the major autosomes to one centromere, producing a single giant chromosome (Novitski et al. 1981). The four arms were arranged in the order 2R 2L · 3L 3R, where the dot indicates the centromere. Surprisingly, these bizarre chromosomes went through meiosis in both males and females, although to no one's surprise, they were transmitted in reduced proportions.
A particularly ingenious example of Ed's Drosophila trickery occurred early in his career (Novitski 1950). Mel and Katie Green needed a particular lozenge allele, which was locked in an inversion, too short for a double crossover. Novitski was able to recover the two exchanges, one in each of two successive generations. When paired with a longer inversion, however, a crossover within the common inverted region produced not a dicentric and acentric pair, but duplication-deficiency chromosomes. Then, by using triploids and waiting for an unusual segregation, Ed was able to get the complementary duplication-deficiency chromosomes into the same gamete. These could be perpetuated in subsequent generations by selecting nondisjunction products. An additional crossover could then reconstitute the original long inversion sequence with the mutant allele in it. Finally, a double crossover within the larger inversion transferred the desired allele to the normal uninverted chromosome, and the Greens had their desired allele in a manageable condition. The procedure and Muller's reaction to it are described in Ed's book (Novitski 2005, pp. 135ff).
Novitski's graduate work involved species other than Drosophila melanogaster (Novitski 1946), but after that time he worked exclusively with that species. He demonstrated early that low-temperature shocks produced the desemination of mated females, rendering them “virgins” (Novitski and Rush 1948). He demonstrated that recombination between some pairs of structurally heterozygous chromosomes produces heteromorphic dyads from which the smaller element is preferentially included in the functional egg nucleus (Novitski 1951). He also studied the fate of double first anaphase bridges formed by a four-strand double exchange in an inversion heterozygote. He showed that, in the tug of war between centromeres at opposite ends of a bridge, the outcome depends on the sources of the chromosomes involved (Novitski 1952; Lindsley and Novitski 1958). Novitski later showed that the very unlikely precise reversion of the roughest-3 inversion could be achieved in heterozygous females when the two breakpoints of the inversion were brought into close proximity by the looped inversion configuration (Novitski 1961).
Other studies included the relationship of crossing over to nondisjunction (Novitski 1967, 1978); an explanation of the “crowding effect”, the tendency for chromosomes in triploids to segregate in roughly equal numbers to opposite poles at the expense of balanced haploid and diploid products (Sandler and Novitski 1957); crossing over within inversion heterozygotes (Novitski and Braver 1954); induced exchanges between the X and Y chromosomes (Lucchesi 1965); and an alternative to Rhoda Grell's distributive pairing hypothesis (Novitski 1964).
One of Novitski's lasting contributions has been an addition to the genetic vocabulary. In 1957, calling attention to frequent examples of altered segregation ratios, he and Larry Sandler coined the expression “meiotic drive” (Sandler and Novitski 1957). (For more on Sandler, see Lindsley 1999.) Soon afterward, Sandler had a golden opportunity to study the phenomenon because of the recent discovery by Yuichiro Hiraizumi of Segregation Distortion in D. melanogaster. Sandler joined Hiraizumi at the University of Wisconsin to work out the details. Ironically, this best-known example of distorted segregation ratios in Drosophila turned out not to be true meiotic drive, since it depends on sperm dysfunction (Hartl 1969). Although many cytological and molecular details are now understood, the molecular basis of the distortion process remains a mystery (Ganetzky 1999).
In addition to the chromosome mechanics of Drosophila, Novitski contributed a number of insights into other areas of genetics. He reported a relationship between the human sex ratio and paternal age (Novitski 1954b). He found a simple, nonmathematical way of showing that the A and B blood group determinants were alleles (Novitski 1982, pp. 403–407). With Everett Dempster, he showed that selection against one of two homozygous classes can lead to apparent heterosis (Novitski and Dempster 1958), which had caused some confusion in Drosophila population experiments. One of Ed's ventures outside Drosophila happened while he was still a student at Caltech. Working with C. A. G. Wiersma, he found that the nerves of the crayfish heart could be stimulated by chemicals. Seeing that acetylcholine had a stimulating effect, they guessed that this substance was actually produced by the nerve (Wiersma and Novitski 1942), which has turned out to be correct. While in Curt Stern's laboratory, he participated in a heroic experiment, producing the important result that “recessive” lethals regularly have slight, but detectable, viability effects in the heterozygous condition (Stern et al. 1952). This is of great significance because this means that the most effective selection against recessive lethals is directed against the much more common heterozygotes. The result also supported an earlier observation of Sturtevant that lethals in natural populations are less frequent than would be expected from their mutation rate if they were completely recessive.
Ed was a natural and self-taught mathematician; he always thought in algebraic terms when considering problems in chromosome behavior. Therefore it was natural that he would gravitate toward computers. When he arrived at Oak Ridge, he encountered a computer called the ORACLE (Oak Ridge Analog Computer and Logical Engine). It was in an air-cooled room full of vacuum tubes. Ed set about to learn how to program using hexadecimal code and later the first version of FORTRAN. He convened a meeting of a few geneticists to introduce them to the new tool and his mathematical proclivities led to fruitful associations with population geneticists such as Everett Dempster and Richard Lewontin.
Michael Ashburner has compiled a comprehensive, three-volume compendium on the biology and genetics of Drosophila, which has become an invaluable reference. Ed coauthored the first volume (Ashburner and Novitski 1976). The second was coauthored by Ted Wright and the third by H. L. Carson and J. N. Thompson, Jr.
Novitski wrote a textbook on human genetics (Novitski 1982). It was intended for undergraduate students and gave considerable attention to social issues, such as radiation effects (an important issue at the time), racial differences, and genetic counseling. As one would expect from Novitski, there were also touches of originality. One example is a picture of several sets of identical twins and, without any instruction, the members of a pair held their hands in similar positions.
Among Novitski's diverse interests was the interpretation of Mendel's results. Were they too good to be true? He remained convinced that some of Fisher's criticisms were unfounded, or at least that the question was still open. He provided several reasons. Some hinge on uncertainty as to the number of plants Mendel scored in determining from progeny which dominant plants were heterozygous. His method of correcting led to a departure from the 2:1 expectation that was opposite and almost equal to Fisher's correction. Ed's approximations were mathematically generalized by his son Charles (C. E. Novitski 2004). Contrary to several who have engaged in this polemic, Ed took the trouble to learn a great deal about garden peas. This led him to infer that Mendel very likely used seed-coat color rather than the usually assumed flower color in the trihybrid crosses. This made it possible to do all the scoring from seeds, removing the necessity for progeny testing and making Fisher's corrections unnecessary (E. Novitski 2004). Was Fisher's hypothesis correct? The debate goes on.
Ed's final paper was published the week of his death (Novitski 2006). It is a critical appraisal of T. H. Morgan, his wonderfully gifted students, and their successors. In typical Novitski style, it is thoughtful, personal, candid, and sometimes acerbic. From first-hand knowledge he makes clear his views of the people and their research.
Ed Novitski also contributed to the advancement of genetic knowledge of Drosophila through his students and postdocs. Among these were Larry and Iris Sandler, Stan Zimmering, John Lucchesi, and Jim Peacock. Dan Lindsley and Claude Hinton were his de facto students, although they were formally students of Sturtevant. He also influenced a number of undergraduates, including Nick Cozzarelli, Mark Ptashne, and Charles Laird.
Despite his powerful intellect and striking originality, Novitski never received a proportionate amount of recognition. Why? The main reason surely is his insistence on continuing to work on chromosome mechanics in Drosophila for its own sake, long after the winds of popularity had moved the center of genetic interest elsewhere. In a more popular field his ability would surely have brought him to the fore. Nevertheless, among Drosophila geneticists, he will always be known as the master manipulator of chromosomes. And stories about his eccentricities and practical jokes will be told whenever Drosophilists get together—and will undoubtedly improve with age.
Edward Novitski is survived by his wife, Esther, whom he cared for lovingly through her long and difficult decline; two sons, Charles and Paul; two daughters, Barbara-Jo and Ellen; and five grandchildren.
Plans are underway in the Genetics Society of America for a Novitski Prize. The details will be announced later.
We are much indebted to Charles Novitski for help with biographical information and for many thoughtful and critical comments.
- Copyright © 2006 by the Genetics Society of America