Bernard Ogilvie Dodge

Bernard Ogilvie Dodge
Born	18 April 1872 Mauston, Wisconsin
Died	9 August 1960
Nationality	American
Alma mater	University of Wisconsin,Columbia University
Scientific career
Fields	Mycology

Bernard Ogilvie Dodge(18 April 1872 – 9 August 1960) was an Americanbotanistand pioneer researcher onheredityin fungi.Dodge was the author of over 150 papers dealing with the life histories,cytology,morphology,pathologyandgeneticsoffungi,and with insects and other animal pests of plants. He made the first studies ofsexual reproductionin the common bread mold,Neurospora.

Dodge's work on the genetics ofNeurosporalaid the groundwork for the discoveries that earnedGeorge Wells BeadleandEdward Lawrie TatumtheNobel Prizein 1958.

Early years

Bernard Ogilvie Dodge was an eighth-generation descendant ofRebecca Nurse,the third of seven children born to Mary Ann and Elbridge Gerry Dodge. Though neither parent had a high school education, both had a strong love for literature, music and learning. Dodge's father was widely acquainted with the writings ofShakespeare,Byron,Chaucer,Spenser,andPope,and supplemented the income from hisMauston, Wisconsinfarm by teaching in the local schools.

Bernard Dodge spent the first 20 years of his life working on the family farm. He recalled to biographer W. J. Robbins that at the age of 10 a bumper crop ofsorghumrequired operation of themillday and night during the rush period of syrup making. At such times Dodge's father, two of Dodge's older brothers, and Dodge worked 18 hours a day, beginning at midnight. (Dodge's job was to stand on the circling horsepower platform and drive the horses, walking sideways to avoid dizziness.) That same winter, Bernard Dodge also worked at the local schoolhouse, one mile away, to sweep out the schoolhouse and build the fire. He earned five cents each school day.

Dodge did not complete hishigh schooleducation until he was 20 years old. He taught high school and then entered theUniversity of Wisconsinas a special student in 1896, only to leave college less than a year later when his funds were exhausted. He returned to teaching until, at the age of 28, he had saved enough money to resume his formal education. He obtained a diploma fromMilwaukee Normal School,returned to teaching a third time (serving as high school principal atAlgoma, Wisconsin,where he also taught botany,physicsandgeometry). Dodge returned to the University of Wisconsin in 1908, at the age of 36, and completed the requirements for the Ph.B. degree in 1909.

In high school, Dodge had a three-month course in botany in which each student was required to collect and identify 75 plants, using the keys of Gray's "School and Field Botany" textbook. Dodge recounted to W. J. Robbins that he "far exceeded the number required". While still a high school principal in Algoma, a chance meeting with an amateurmycologist(aBohemiantailor with a basket full of "Pilze" (mushrooms) that were "gut fur essen" (good to eat)) aroused an interest in collecting fungi. Dodge sentspecimensto the University of Wisconsin for identification, bought Atkinson's book onmushrooms,and his wife Jennie presented him with MacIllwain's "One Thousand Edible Mushrooms" as a Christmas present.

At the University of Wisconsin, Dodge studied Botany underR. A. Harper.When Harper transferred toColumbia Universityin New York, he suggested that Dodge undertake graduate work there. Dodge accepted a minor position as an Assistant and Research Fellow in Botany at Columbia. Dodge received his Ph.D at the age of 40; his first paper was published when he was 42.

Dodge remained at Columbia as Instructor of Botany until 1920, when he accepted an appointment as Plant Pathologist (in fruit diseases) in the Bureau of Plant Industry of theU.S. Department of Agriculture.During his eight years inWashington, D.C.,he initiated his studies ofNeurospora.

Neurosporaresearch

As a graduate student and instructor at Columbia, Dodge investigated thetaxonomyandreproductionof species ofAscobolaceae.He found that theascosporesof several species of Ascobolus which rarelygerminateunder ordinary conditions on artificial media, do so readily after being subjected to 50-70 degrees Celsius for five to 10 minutes. Dodge discovered this completely by accident: after trying several methods to germinate the ascospores of Ascobolus (without success). One day Dodge temporarily set down a batch of test plates inside a hot-airsterilizerwhich was not running, while he went to teach a class. When Dodge returned, he was dismayed to find that someone had lit the oven in the interim, and the temperature inside had reached over 70 degrees. Dodge removed the plates, assumed that the spores had been killed, but before discarding the old plates he examined them under amicroscope.He was astounded to find that most of the spores had germinated. This discovery proved to be of importance later for his studies ofNeurospora.

Though Dodge considered himself primarily a mycologist and a plant pathologist, his study ofNeurosporais regarded by many as his major work. As he told W. J. Robbins:

I was, 1925-6, highly interested in studies on the blackberryrusts,short and long cycle forms (species). […] I had found that I could pass the rust on the Black Diamondblackberry(dewberry) by grafting to young shoots of this species, and was trying to culture the rest oncornmealagarin plates and flasks. So I had several plates and flasks (250 cc) standing on shelves in the Arlington Farm greenhouses. I was much concerned to find thatMonila sitophilahad gotten into some of the flasks as well as some plates. Practically all of them were soon bearingperitheciaresembling those Dr. C. L. Shear had shown me and [had] asked me to try to germinate the ascospores. I was so much excited and interested in my rust studies that I could not leave those experiments to help my superior out. I did suggest trying to make those spores germinate by heating them. […] Several weeks had passed when this red bread mold developed in my greenhouse flasks and plates. Just on a chance I inverted plates of corn [meal] agar on cultures of perithecia shooting spores so spores were shot upward and scattered about. I put some of these plates in a drying oven and heated them as I had gone many times to make ascospores of Ascobolus to germinate. By next morning a high percentage of the mold had germinated.

The ability to germinate the ascospores ofNeurosporamade it possible to define itslife cycle,distinguish species, make crosses between species, and grow thehaploidoffspring.

Over the next 30 years, Dodge published over 40 papers onNeurospora,which was easy to grow and required little space (and only a few days) to complete its life cycle. These advantages madeNeurospora,in many respects, an ideal organism for the investigation of genetics and biochemical genetics. Dodge convincedThomas Hunt Morganof the advantages ofNeurosporaand Morgan took cultures with him when he transferred from Columbia University to theCalifornia Institute of Technologyin 1928.

Influence

Dodge never developed a larger program involving an extensive study of spontaneous and induced mutations orchromosomemapping. In fact, he regarded his research onNeurosporaas an "extra", carried on while pursuing his official duties as a plant pathologist. Nevertheless, Dodge's investigations laid the foundation for the use ofNeurosporain the investigation of genetics andbiochemical geneticson a worldwide basis. In a letter to Dodge on November 1, 1959, George Beadle wrote:

Without your pioneer work, those of us who have made use ofNeurosporanever could have done what we did. [..]Neurosporahas been good to many of us and it is your baby more than anyone else's. Thanks again for giving it to genetics.

In his own Nobel Lecture, Edward L. Tatum wrote:

I shall not enumerate the factors involved in our selection of thisorganismfor the production of chemical or nutritionally deficient mutants, but must take this opportunity of reiterating our indebtedness to the previous basic finds of a number of investigators. Foremost among these, to B. O. Dodge for this establishment of this ascomycete as a most suitable organism for genetics studies; and to C. C. Lindegren, who became interested inNeurosporathrough T. H. Morgan, a close friend of Dodge.

Another prominent scientist inspired directly by Dodge wasEsther Lederberg,who worked with him at theNew York Botanical Gardenas an intern while she was an undergraduate atHunter College,Lederberg (née Esther Miriam Zimmer) worked with Dodge under three scholarships between 1941 and 1942, conducting research inheterokaryosisinNeurosporatetrasperma. She wrote her Master's thesis onNeurospora crassaand published two papers onNeurospora crassabefore beginning her studies of the bacteriumEscherichia coli,and her highly influential development of replica plating, the discovery of fertility factor F (inheritable sex change due to viral infection), temperate lambda bacteriophage, and her pioneering work in transduction.

Professional associations

• National Academy of Sciences
• Sigma Xi
• American Association for the Advancement of Science
• Linnean Society of London
• British Mycological Society(honorary)
• Torrey Botanical Club
• Botanical Society of America

Further reading

• William J. Robbins, "Bernard Ogilvie Dodge",Biographical MemoirsVol. XXXVI, National Academy of Sciences, Columbia University Press, New York, NY, 1962, pp. 85–124.
• Francis T. Ryan and Lindsay S. Olive, "The Importance of B. O. Dodge's Work for the Genetics of Fungi",Bulletin of the Torrey Botanical Club,Vol. 88, No. 2 (Mar-Apr 1961), pp. 118–120.
• Obituary,Proceedings of the Linnean Society of London,Vol. 173, Issue 1, p. 64-68.

External links

• National Academy of Sciences Biographical Memoir