Lilian Vaughan Morgan

Lilian Vaughan Morgan
Born Lilian Vaughan Sampson
(1870-07-07)July 7, 1870
Hallowell, Maine
Died December 6, 1952(1952-12-06) (aged 82)
Los Angeles, California
Nationality American
Other names Lilian Vaughan Sampson
Alma mater Bryn Mawr (B.S.), Bryn Mawr (M.S.)
Known for Discovery of attached-X chromosomes, discovery of ring chromosomes
Scientific career
Fields Genetics
Institutions Bryn Mawr College
Columbia University
California Institute of Technology

Lilian Vaughan Morgan (née Sampson; July 7, 1870 – December 6, 1952) was an American experimental biologist who made seminal contributions to the genetics of Drosophila melanogaster, which cemented its status as one of the most powerful model systems in biology. In addition to her scientific career, she was involved in science education and was one of the founders of the Children's School of Science in Woods Hole, Massachusetts.

Early life

Morgan was born in 1870 in Hallowell, Maine. She was orphaned at the age of three when her parents and younger sister died of tuberculosis. After the death of her parents, she and her older sister Edith were raised by her maternal grandparents in Germantown, Pennsylvania.

Early research career

Morgan enrolled as an undergraduate student at Bryn Mawr in 1887. She majored in biology and was advised by Martha Carey Thomas. After her graduation with honors in 1891, she spent the summer at the Marine Biological Laboratory in Woods Hole, Massachusetts, where Edmund Beecher Wilson, one of her previous zoology professors, introduced her to her future graduate advisor and husband Thomas Hunt Morgan.[1]

In the autumn of 1891, a European fellowship for the best graduate in class enabled Morgan to go to Europe and study the musculature of chitons at the University of Zurich with Arnold Lang, a comparative anatomist and student of Ernst Haeckel.[1] She returned to Bryn Mawr in 1892, where she received her MS in biology in 1894, advised by Thomas Morgan. After graduation, she published her work on the musculature of chitons, returned to Woods Hole as an independent investigator, and spent seven summers investigating breeding, development and embryology in amphibia.[1]

Family life

In 1904, at the age of 34, she married Thomas Hunt Morgan and moved to New York City, where he took a position at Columbia University. That following summer, they moved to California, where she researched and published work on planarian regeneration at the Stanford Marine Laboratory. She would not publish another paper for sixteen years. During this time, she supported her husband's career and raised four children: Howard Key Morgan, born 1906; Edith Sampson Morgan, born 1907; Lilian Vaughan Morgan, born 1910; and Isabella Merrick Morgan, born 1911. Shine and Wrobel (1976) note that one key to Thomas Hunt Morgan's success was that his personal affairs were entirely handled by Lilian Morgan, freeing him to focus on his research.[2] The family spent their winters in New York and returned in the summers to Woods Hole, where she maintained a summer house for children, relatives and her husband's graduate students. She maintained this house for many years, eventually equipping it for science lessons for children.[1]

Involvement in science education

With several other women, Morgan founded the Summer School Club at Woods Hole in 1913, which is now the Children's School of Science, and served as its first educational chairperson and Science Committee Chair in 1914. She preferred working outdoors with children to conduct experiments and discuss problems.[1]

Later research career

After her children were old enough, Morgan returned to the laboratory to study Drosophila genetics after briefly considering studying the violin. Her husband refused to collaborate with her; instead, he merely gave her working space in his laboratory at Columbia University, where she maintained her own Drosophila stocks and held no official position.[1] Her husband and the other male scientists never became comfortable with her presence in the lab, whose atmosphere was "a little like that of an exclusive men's club."[1] Morgan may also have felt isolated because she was older than the other women and was neither outgoing nor talkative, according to Alfred Sturtevant. Because she didn't hold an official position, she never attended a scientific meeting and never presented a paper at a conference.[1]

Major research accomplishments

Morgan discovered the attached-X[3] and ring chromosomes in Drosophila melanogaster. Normal Drosophila X-chromosomes have one centromere located on one end of the chromosome, while attached-X chromosomes are composed of two X-chromosomes that share a single centromere. These compounds are transmitted as a single entity exclusively from mother to daughter. Morgan's attached-X chromosome strain has proved invaluable for Drosophila genetics because it allows mutant alleles on a different X chromosome to be maintained clonally in a stock of males, which do not undergo recombination.

Morgan's second major contribution to the Drosophila genetic toolkit was the discovery of ring chromosomes.[4] Ring chromosomes were discovered from their unusual frequencies of recombination in an attached-X stock, which revealed a circularized X-chromosome upon cytological examination. Ring-X chromosomes are unstable in early development, a phenomenon that has been applied to generate mosaic tissues containing XX and XO cells during mitosis that bear recessive loss-of-function alleles of specific X-linked genes.

Later life

Morgan and her family moved to California in 1928, where she continued her Drosophila research at the California Institute of Technology in Pasadana while her husband Thomas Hunt Morgan became the division head. Her husband died in 1945; one year afterwards, Morgan would receive her first official appointment of her life as a Research Associate at the age of 76.[1] She died in 1952 at the age of 82 in Los Angeles.

List of Publications

  • Sampson, L. V. 1894. Die Muskulatur von Chiton. Jenaischen Zeitschrift für Naturwissenschaft 28: 460-468.
  • Sampson, L. V. 1895. The musculature of chiton. Journal of Morphology 11:595-628.
  • Sampson, L. V. 1900. Unusual modes of breeding and development among anura. Amer. Naturalist 34:687-715.
  • Sampson, L. V. 1904. A contribution to the embryology of Hylodes martinicensis. Araer. J. Anat. 3: 473-504.
  • Morgan, L. V. 1905. Incomplete anterior regeneration in the absence of the brain in Leploplana litloralis. Biol. Bull. 9:187-193.
  • Morgan, L. V. 1906. Regeneration of grafted pieces of planarians. J. Exp. Zool. 3:269-294.
  • Morgan, L. V. 1922. Non-criss-cross inheritance in Drosophila melanogaster. Biol. Bull. 42:267-274.
  • Morgan, L. V. 1925. Polyploidy in Drosophila melanogaster with two attached X chromosomes" Genetics 10:148-178.
  • Morgan, L. V. 1926. Correlation between shape and behavior of a chromosome" Proc. Natl. Acad. Sci 12:180-181.
  • Morgan, L. V. 1929. Composites of Drosophila melanogaster. Carnegie Inst. of Wash. Publ. No. 399: 225-296.
  • Morgan, L. V. 1931. Proof that bar changes to notbar by unequal crossing-over" Proc. Natl. Acad. Sci 17:270-272.
  • Morgan, L. V. 1933. A closed X chromosome in Drosophila melanogaster" Genetics 18:250-283.
  • Morgan, L. V. 1938a. Origin of attached-X chromosomes in Drosophila melanogaster and the occurrence of non-disjunction of X's in the male. Amer. Naturalist 72:434-446.
  • Morgan, L. V. 1938b. Effects of a compound duplication of the X chromosome of Drosophila melanogaster" Genetics 23:423-462.
  • Morgan, L. V. 1939. A spontaneous somatic exchange between non-homologous chromosomes in Drosophila melanogaster" Genetics 24:747-752.
  • Morgan, L. V. 1947. A variable phenotype associated with the fourth chromosome of Drosophila melanogaster and affected by heterochromatin" Genetics 32:200-219.
  • Morgan, T. H., H. Redfield, and L. V. Morgan. 1943. Maintenance of a Drosophila stock center, in connection with investigations on the germinal material in relation to heredity. Carnegie Inst. Wash. Yearbk. 42:171-174.
  • Morgan, T. H., A. H. Sturtevant, and L. V. Morgan. 1945. Maintenance of a Drosophila stock center, in connection with investigations on the germinal material in relation to heredity. Carnegie Inst. Wash. Yearbk. 44:157-160.

References

  1. 1 2 3 4 5 6 7 8 9 Keenan, Katherine (1983). "Lilian Vaughan Morgan (1870-1952): Her life and Work". Am. Zool. 23: 867–876. doi:10.1093/icb/23.4.867.
  2. ↑ Shine, Ian; Beadle, Sylvia Wrobel (1976). Thomas Hunt Morgan : pioneer of genetics (Paperback ed.). Lexington, Ky.: University Press of Kentucky. ISBN 978-0-8131-9337-3.
  3. ↑ Morgan, L.V. (1922). "Non-criss-cross inheritance in Drosophila melanogaster". Biol. Bull. 42: 267–274. doi:10.2307/1536473.
  4. ↑ Morgan, LV (March 1926). "Correlation between Shape and Behavior of a Chromosome". Proceedings of the National Academy of Sciences of the United States of America. 12 (3): 180–1. doi:10.1073/pnas.12.3.180. PMC 1084483. PMID 16576974.
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