Dr.Edward B. Lewis, an American geneticist, was born in Wilkes-Barre, Pennsylvania. In 1939, he obtained BA in Biostatistics from University of Minnesota, where he worked with Drosophila melanogaster in C. P. Oliver’s lab. Later, in 1942, he received his Ph.D. degree from Caltech (California Institute of Technology) under the supervision of A. Sturtevant.

Dr. Christiane Nüsslein-Volhard, a German developmental biologist, was born in Magdeburg, Germany. She studied biology at Goethe University in Frankfurt received her Ph.D. degree from University of Tübingen in 1974.

Dr. Eric F. Wieschaus, an American developmental biologist, was born in South Bend, Indiana. He obtained B.S. in Biology in 1969 from University of Notre Dame and received his Ph.D. degree in Biology from Yale University in 1974.

Life begins from a single cell (fertilized egg), which divides and forms an entire organism. During the initial stages of embryogenesis, the dividing cells look alike but with time the fate of the cells is decided. For example, cells go to make up the liver, heart, skin cells etc. Little was known then about the mechanisms by which a multicellular and complex organism develops from a single cell. In 1970s, Edward Lewis, in fruit flies, discovered that the position of organs in a body segment matched the loci of the corresponding genes on the chromosome. Later, in 1980, Christiane Nüsslein-Volhard and Eric Wieschaus identified and classified 15 genes, which regulate cell fates in fruit fly, crucial for Drosophila embryogenesis.

"For their discoveries concerning the genetic control of early embryonic development", Edward B. Lewis, Christiane Nüsslein-Volhard and Eric F. Wieschaus were jointly awarded the Nobel Prize in Physiology or Medicine in 1995.

References:

"The Nobel Prize in Physiology or Medicine 1995". Nobelprize.org. Nobel Media AB 2014. Web. 12 Oct 2017. http://www.nobelprize.org/nobel_prizes/medicine/laureates/1995/