Perspectives
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Copyright Ó 2007 by the Genetics Society of America Perspectives Anecdotal, Historical and Critical Commentaries on Genetics Edited by James F. Crow and William F. Dove Tending Neurospora: David Perkins, 1919–2007, and Dorothy Newmeyer Perkins, 1922–2007 Rowland H. Davis1 Department of Molecular Biology and Biochemistry, University of California, Irvine, California 92697 HE death of David Perkins and his wife, Dorothy compelled to retire ‘‘officially’’ at the age of 70 in T Newmeyer Perkins, just after the new year is a 1989, David maintained an active laboratory at Stanford great loss to fungal genetics, but the work to which they as professor emeritus until his death in 2007. devoted their lives has left the field in vibrant health. Dorothy (‘‘Dot’’) Lorraine Newmeyer Perkins died The contributions that David made, with the long- of natural causes on January 6, 2007, a few days after standing collaboration and support of his wife, extend David. Born on May 28, 1922, she ultimately had four over many areas of study using the model organism, the siblings. Both of her parents were musicians. Dot main- fungus Neurospora. These include pioneering work tained an interest in music, but yearned to have a career on its formal genetics, the most extensive studies per- as a research scientist. Thinking at the time that this goal formed with any eukaryotic microorganism at the time: was unattainable for a woman, she enrolled in the its cytogenetics, its genomic organization, the biology Philadelphia College of Pharmacy and graduated with of its mating systems, and an extensive exploration of its high honors in the mid-1940s. She took a job as a natural populations. During that time, David sustained chemist in a drug factory, but escaped its routines for a the research of investigators worldwide by methodo- position as a lab technician, and later as a graduate logical innovations, running compendia of mutants student, with Edward L. Tatum at Yale University. She and genetic maps, recruitment of women and young completed her Ph.D. at Stanford in 1951, following investigators, and illumination of the path to future Tatum’s move back to the West Coast. She married research problems. He thereby furthered the role of David Perkins in 1952 and worked thereafter on Neurospora as a model for studies of filamentous fungi Neurospora genetics as a Senior Research Scientist in in general for .50 years (Davis 2000). Indeed, no David’s lab. Poor health forced her to work part time in single investigator can claim a greater role in the origin mid-career and to retire early, although she continued and development of the large field of fungal genetics to contribute to the work of the laboratory. and biology. David and Dorothy Perkins are survived by their only David Dexter Perkins died on January 2, 2007, at the child, Susan, born in 1956. In addition to science, the age of 87 in Stanford, California, after a short illness. entire family enjoyed hiking and camping trips in the Born in Watertown, New York, on May 2, 1919, he California coast range and Sierra Nevada Mountains. received his bachelor’s degree in biology in 1941 at the Sue Perkins became a geologist, and she and her hus- University of Rochester. After serving as an intelligence band, John Bergin, live in Seattle. officer in the Army Air Force in England during World War II, David received his Ph.D. degree in 1949 at Columbia University for work in genetics with Francis AMAN,AMODEL,AMISSION Ryan. He took a position in the Biology Department at David entered the field of genetics in one of its glori- Stanford University the same year. Since 1951, David’s ous decades. Beadle and Tatum had begun a revolution- work on the genetics of the fungus Neurospora con- ary program in 1941 with their discovery of mutations in tinued without interruption for 58 years. Although Neurospora that blocked biosynthetic reactions (Beadle and Tatum 1941). Francis Ryan, David’s Ph.D. mentor, 1Author e-mail: [email protected] was an early postdoctoral associate of the Beadle–Tatum Genetics 175: 1543–1548 (April 2007) 1544 R. H. Davis products (ascospores) of a single meiosis, together with the increasing availability of biochemical markers, pop- ularized Neurospora for genetic investigations. With the further investigations and development of standard strains by Carl Lindegren in the 1930s and the Beadle laboratory in the 1940s, tetrad analysis came into its own, and David became one of its greatest practitioners. Formal genetic work and the formation of the Neu- rospora community: David’s early work on N. crassa foc- used on linkage analysis using tetrads and random progeny to study mapping functions and interference and to construct dependable genetic maps. The meth- ods were especially useful for species with unordered tetrads. He could now use many new mutants isolated in his own and other laboratories, especially Beadle’s, which had by then moved to the California Institute of Technology. At this time, he and Dot had teamed up Figure 1.—David and Dot Perkins in the 1970s. Photo- with Raymond Barratt, another Tatum student, to pub- graph kindly provided by Susan Perkins. lish the first ‘‘compendium’’ of Neurospora mutants in 1954 (Barratt et al. 1954). This was less a curatorial job than the first bible of Neurospora genetic theory and laboratory at Stanford in 1941 and returned to his home techniques. The long work included not only theoret- base at Columbia University, dedicated to the study of ical analysis of recombination, but also phenotypic de- microbial and biochemical genetics. After World War II, scriptions of all known mutants and their alleles and David joined Ryan as one of the first generation of maps of Neurospora’s seven chromosomes. Barratt had students in the new era. David, inspired by Neurospora already proposed the main nomenclatural and certain tetrad analysis, chose the corn pathogen, Ustilago maydis, other conventions of the field. Their joint work led for his thesis work, but switched to Neurospora there- Barratt, at Dartmouth after 1954, to establish the Fungal after, doubtless recognizing its methodological advan- Genetics Stock Center, to organize the first Neurospora tages and the increasing visibility of Neurospora research. Information Conference (now the Fungal Genetics Con- David eschewed direct involvement in biochemical work ference), and to publish the Neurospora Newsletter (now and instead embarked upon detailed studies on the the Fungal Genetics Newsletter). These achievements estab- genetics of Neurospora, which he continued for the rest lished and bound together a Neurospora research com- of his career. This put him in a unique position as a munity that has endured to this day. David, while still pioneer in the genetics of haploid eukaryotes and as the collaborating with Barratt in the curatorial work, con- facilitator of research by all later investigators who used tinued his steady output of original work. He would Neurospora as an experimental organism. As Charley soon become the central player in keeping the Neuros- Yanofsky said in a recent memorial, ‘‘Beadle and Tatum pora community together and in defining Neurospora initiated research using this organism, but it was David as a model organism for many areas of research. Part of who made certain that this interest would continue.’’ the success of this effort reflects David’s instilling a lack The sexual phase of Neurospora was discovered by of competitiveness into the field as a whole; he shared B. O. Dodge (Shear and Dodge 1927). An arresting and trusted, expecting the same from others. (A para- feature of the eight-spored species, N. crassa and N. gon of fairness, he never put his name on articles from sitophila, was the alignment of meiotic products (each his lab unless he had done some of the experimental duplicated in a postmeiotic division) in the linear tet- work.) rad, or ascus. The products of the first-division segrega- Chromosomal aberrations and cytogenetics: In the tion remain in the upper and lower halves, and the early 1960s, David focused on chromosomal aberra- second-division segregation products remain adjacent. tions. X-ray and ultraviolet mutagenesis, the latter Dodge discovered not only that alleles of a single gene commonly used by Neurospora workers, yield chromo- (the mating type A/a, in his case) segregated 4A:4a, but somal rearrangements, some associated with mutations also that some asci displayed a 2A:2a:2A:2a pattern. The at the breakpoints. David’s linkage studies uncovered latter was interpreted by Beadle, among others, as a these aberrations, which he interpreted straightfor- result of second-division segregation, showing clearly wardly as chiefly reciprocal or insertional translocations. that crossing over occurred at the four-strand stage of Such rearrangements led to characteristic patterns meiosis. Analysis of tetrads displayed the highly de- of ascospore abortion in tetrads. David developed his terministic nature of meiosis more clearly than earlier observations into a methodology of detecting and char- analyses. Nevertheless, the technical ease of dissecting acterizing genetic aberrations in ways the rest of the Perspectives 1545 community could use routinely for creating duplica- gone from what many might have considered an exotic tions, deficiencies, and fine-scale mapping of closely hobby to a major tool in the study of genome dynamics linked mutants by duplication coverage. in this simple organism. One of the most useful tools emerging from this work In 1974, Namboori Raju (‘‘Raju’’) joined the Perkins was a multiply translocated strain called alcoy, in which laboratory and extended its work in important ways. interchanges had occurred among six of Neurospora’s For .32 years, Raju worked closely with David, taking seven chromosomes (Perkins et al. 1969). The strain advantage of a variety of mutants affecting meiotic also carried the ‘‘visible’’ mutations al-1, cot, and ylo development in Neurospora.