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Barbara McClintock and Her Jumping Genes By: Angela Salmon Curricular Fit: This vignette can fit into any science class when discussing the importance of scientific research. Specifically this can be used for Biology 30 when discussing genetics (Unit 3: Cells, Chromosomes, and DNA). The early 20th Century was a time when genetics research was in its infancy. Mendel’s ideas of heredity were not widespread. Much important information was being discovered: the composition and structure of DNA, what a chromosome looked liked, how genes are arranged along the chromosome. The research that was occurring was endless. As more discoveries were made, more research needed to be done. There were still many things about genetics that were not known. Barbara McClintock was born in 1902 in Hartford, Connecticut. This girl grew to be a curious scientist with a passion for genetics. She gained her degree and her Ph.D. from Cornell University College of Agriculture. Most women at that time went on to become teachers but Barbara always had a zest for research. Botany was an accepted field for women to work in and Barbara had gained an interest in corn (Zea Mays). For most of her career she worked in a permanent position at Cold Spring Harbor facility run by the Carnegie Institute of Washington. Barbara was elected the first woman president of the Genetics Society of America in 1944. She became the third woman named to the National Academy of Science in 81 years. Barbara’s research was pioneering in the field of genetics. Her ideas were fresh and new, she was not afraid to question existing beliefs held by most geneticists as truths. The popular idea then was that genes were arranged along a chromosome like pearls on necklace, static and unmoving. In her research with corn she discovered that genes were not stationary, they actually had the ability to move within the chromosome. These regions were named transposons or "jumping genes". She presented her ideas on transposons at the 1951 Cold Spring Harbor Symposium where the reaction she received from her colleagues was less than rewarding. Most scientists were hesitant to acknowledge her discoveries as valid truths. This woman was the President of the Genetics Society of America just seven years earlier! Many people now feel that McClintock’s work was too advanced for many of her colleagues to comprehend at the time. Despite this negative reaction she continued her research on corn and made many other genetic discoveries including the presence of telomeres in chromosomes and the effects of traumatic events creating mutations in genetic material. It was not until the 1960’s that other scientists started to agree with her research when they found evidence of transposons in bacteria. Other geneticists were finally recognizing her work more than ten years later. Her pioneering research on transposons and other genetic discoveries went un-rewarded until 1983 when she received the Nobel Prize in Medicine or Physiology. Even though Barbara did not gain immediate recognition of her studies, she never gave up. Her passion for genetics and its research was never lost. We are aware of many things today, including transposons, because of the groundbreaking research done by these early scientists who had the curiosity to keep asking new questions and conducting new research. Questions What do you think helped Barbara McClintock to be a great and successful scientist? Why do you think other scientists did not readily accept the genetic research findings of Dr. McClintock? How much of scientific knowledge today can we assume is fact and how much of it is theory? How can we apply this story to our understanding of scientific research today? Do scientific discoveries happen overnight? References http://heg-school.awl.com/bc/companion/cmr2e/activity/VR/VR05.htm http://www.cshl.org/public/mcclintock.html http://heg-school.awl.com/bc/companion/cmr2e/activity/VR/VR05a.htm http://www.astr.ua.edu/4000ws/MCCLINTOCK.html © Angela Salmon. Reprinted with permission from Angela Salmon. All rights reserved. |