05/11/2004
Rhabditoidea
Ellsworth C. Dougherty first recognized the potential of C. briggsae, which had been found by Margaret Briggs in a pile of leaves on the campus of Stanford University in Palo Alto, California, in 1944 and used in her MS studies under the direction of Dr. Arthur C. Giese (Briggs, 1946; Gochnauer, 2004). Briggs studied the lifecycle of what she identified as Rhabditis sp. in association with bacteria and in various culture media devoid of other organisms. She showed that the population could not be sustained in the absence of bacteria or even on dead bacterial cells; living bacteria were a necessary food source. However, survival of individuals was greater on some bacteria-free media than others.
Dougherty was alerted to the work of Margaret Briggs by George Wells Beadle of Stanford University (Gochnauer, 2004). Beadle and his colleague, Edward Tatum, were two of three Nobel laureates in medicine in 1958. Their 1941 paper on genetic control of biochemical reactions in the bread mold, Neurospora, validated the one-gene, one-enzyme hypothesis that became a cornerstone of biochemical genetics.
Later (1949), Dougherty and Victor Nigon of France described the nematode used by Briggs as Rhabditis briggsae (Dougherty and Nigon, 1949) and later as Caenorhabditis briggsae.
Dougherty studied the nutritional requirements and axenic cultivation of Caenorhabditis species, particularly C. briggsae, until his death in 1965. In the course of his studies, Dougherty recognized the potential for using C. briggsae in studies of genetics and developmental biology because of ease of culture and maintenance, different reproductive patterns (hermaphroditism and sexual), few chromosomes, less than 1000 cells, etc. Eventually, C. elegans was selected as the model species for all the same reasons and because it was considered more common in nature.
Margaret Briggs went on to complete a PhD in 1950 at the University of Wiscosin, Madison under the direction of Dr. Liz McCoy. Later, she worked at Woods Hole, married and became Margaret Briggs Gochnauer (Gochnauer, 2004). Her PhD research was on responses of R. briggsae to antibiotics (Gochnauer and McCoy, 1954) .
Interestingly, until the mid 1970s, people working in developmental biology frequently confused C. briggsae and C. elegans and many of the cultures being used were mis-identified. In the mid 1970s, graduate student Paul Friedman working with Ed Platzer at UC Riverside developed the diagnostic criteria for separating the two species and resolved the confusion (Friedman et al, 1977).
Briggs, M.P. 1946. Culture methods for a free-living soil nematode. MA Thesis, Stanford University, 63p.
Dougherty, E.C. and V. Nigon. 1949. A new species of the
free-living nematode genus Rhabditis of interest in comparative
physiology and genetics. J. Parasitol. 35: 11.
Dougherty, E.C., E.L. Hansen, W.L. Nicholas, J.A. Mollett, and E.A.
Yarwood. 1959. Axenic cultivation of Caenorhabditis briggsae (Nematoda:
Rhabditidae) with unsupplemented and supplemented chemically defined media.
Ann. N.Y. Acad. Sci. 77: 176-217.
Friedman, P.A., E.G. Platzer, and J.E. Eby. 1977. Species differentiation in
C. briggsae and C. elegans. J. Nematol. 9: 197-203.
Gochnauer, M.B. and E. McCoy. 1954. Responses of a soil nematode, R.
briggsae, to antibiotics. J. Exp. Zool. 125:377-406.
Gochnauer, N. 2004. (Daughter of Margaret Briggs Gochnauer), personal communication.
Nicholas, W.L., E.C. Dougherty, and E.L. Hansen. 1959. Axenic cultivation of
C. briggsae (Nematoda: Rhabditidae) with chemically undefined supplements;
comparative studies with related nematodes. Ann. N.Y. Acad. Sci. 77:
218-236.
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