My Science School

Christiane Nusslein-Volhard, (born October 20, 1942, Magdeburg, Germany), German developmental geneticist who was jointly awarded the 1995 Nobel Prize for Physiology or Medicine with geneticists Eric F. Wieschaus and Edward B. Lewis for their research concerning the mechanisms of early embryonic development. 

In the early 1990s Nusslein-Volhard began studying genes that control development in the zebra fish Danio rerio. These organisms are ideal models for investigations into developmental biology because they have clear embryos, have a rapid rate of reproduction, and are closely related to other vertebrates. Nusslein-Volhard studied the migration of cells from their sites of origin to their sites of destination within zebra fish embryos. Her investigations in zebra fish have helped elucidate genes and other cellular substances involved in human development and in the regulation of normal human physiology.

In addition to the Nobel Prize, Nusslein-Volhard received the Leibniz Prize (1986) and the Albert Lasker Basic Medical Research Award (1991). She also published several books, including Zebrafish: A Practical Approach (2002; written with Ralf Dahm) and Coming to Life: How Genes Drive Development (2006).

Credit : Britannica 

Picture Credit : Google

The 1995 laureates in physiology or medicine are developmental biologists who have discovered important genetic mechanisms which control early embryonic development. They have used the fruit fly, Drosophila melanogaster, as their experimental system. This organism is classical in genetics. The principles found in the fruit fly, apply also to higher organisms including man.

Using Drosophila Nüsslein-Volhard and Wieschaus were able to identify and classify a small number of genes that are of key importance in determining the body plan and the formation of body segments. Lewis investigated how genes could control the further development of individual body segments into specialized organs. He found that the genes were arranged in the same order on the chromosomes as the body segments they controlled. The first genes in a complex of developmental genes controlled the head region, genes in the middle controlled abdominal segments while the last genes controlled the posterior (“tail”) region. Together these three scientists have achieved a breakthrough that will help explain congenital malformations in man.

The fertilized egg is spherical. It divides rapidly to form 2, 4 , 8 cells and so on. Up until the 16-cell stage the early embryo is symmetrical and all cells are equal. Beyond this point, cells begin to specialize and the embryo becomes asymmetrical. Within a week it becomes clear what will form the head and tail regions and what will become the ventral and dorsal sides of the embryo. Somewhat later in development the body of the embryo forms segments and the position of the vertebral column is fixed. The individual segments undergo different development, depending on their position along the “head-tail” axis. Which genes control these events? How many are they? Do they cooperate or do they exert their controlling influence independently of each other?
This year’s laureates have answered several of these questions by identifying a series of important genes and how they function to control the formation of the body axis and body segments. They have also discovered genes that determine which organs that will form in individual segments. Although the fruit fly was used as an experimental system, the principles apply also to higher animals and man. Furthermore, genes analogous to those in the fruit fly have been found in man. An important conclusion is that basic genetic mechanisms controlling early development of multicellular organisms have been conserved during evolution for millions of years.

Credit : Nobel Prize 

Picture Credit : Google

Christiane Nusslein-Volhard is a German geneticist, who was the co-recipient of the 1995 Nobel Prize in Physiology or Medicine for her research on the mechanisms of early embryonic development. Christiane Nusslein-Volhard was born in Heyrothsberge, Germany, in 1942. Christiane studied biology at Goethe University in Frankfurt and biochemistry at Eberhard-Karl University, Tubingen, before undertaking graduate studies at the Max Planck Institute.

Upon completing her PhD in genetics in 1973, Chritiane joined the University of Basel. There she undertook gene study on Drosophila, or fruit flies, an important model organism in genetics. In 1978, she joined the European Molecular Biology Laboratory in Heidelberg. Christiane and her research partner Eric wieschaus studied the embroyonic development of fruit flies and, around 1980, succeeded in identifying and classifying the 15 genes that direct the cells to form a new fly. Their findings had major implications for our understanding of human reproduction, as well. In 1981 she returned to Tubingen, where she served as director of the Max Planck Institute for Developmental Biology from 1985 to 2015. She won the Albert Lasker Award for Basic Medical Research in 1991 and the Nobel Prize in Physiology or Medicine in 1995, together with Eric Wieschaus and Edward B. Lewis.

Chritiane expanded her research beyond Drosophila to vertebrates. In the early 1990s, she began studying genes that control development in the zebra fish Danio rerio. Her investigations in zebra fish have helped elucidate genes and other cellular substances involved in human development.

Picture Credit : Google

The successful use of insulin in treating human patients followed. But because Best did not receive his medical degree until 1925, he did not share the Nobel Prize for Physiology or Medicine awarded to Banting and J.J.R. Macleod in 1923 for their role in the work. Best also discovered the vitamin choline and the enzyme histaminase. He was one of the first to introduce anticoagulants in treatment of thrombosis (blood clots).

In May 1921, while still an undergraduate, Best became a laboratory assistant to Banting at the University of Toronto. In the months that followed, they performed their prizewinning research on insulin. Best continued as research associate in the Banting and Best Department of Medical Research, which was created at the university in 1923, and he succeeded Banting as its director (1941–67). With Banting he wrote Internal Secretions of the Pancreas (1922).

The first clinical tests on a human patient were conducted on a severely diabetic 14-year-old boy. Although the injections of the extract failed to have resoundingly beneficial effects, the Toronto team continued to experiment. A short while later Collip made a breakthrough in purifying the extract, using alcohol in slightly over 90 percent concentration to precipitate out the active ingredient (insulin). At the same time, though, personal tension was mounting among the four scientists, as Banting became increasingly bitter toward Macleod and pitted himself and Best against Collip in the race to purify the extract. At the end of January, Collip came to Banting and Best’s lab and informed the two that although he had discovered a method to produce pure extract, he would share it only with Macleod. It was only Best’s quick restraint that stopped Banting from attacking Collip. Fortunately for the future of insulin an uneasy agreement made a few days later allowed them to continue to work together. On May 3, 1922, Macleod, representing the group, announced to the international medical community at a meeting of the Association of American Physicians that they had discovered “insulin”—the antidiabetic agent.

Credit : Britannica 

Picture Credit : Google

Charles Best was an American-Canadian scientist, who co-discovered insulin, a critical milestone in the treatment of diabetes. Charles Best also discovered the vitamin choline and the enzyme histaminase. He was among the first to introduce anticoagulants in the treatment of blood clots.

Best was born in Maine, the U.S., in 1899. He grew up in Pembroke before joining the University of Toronto, Toronto, Canada, to study medicine in 1915, but his studies were interrupted by the onset of the First World War. He served as an infantry soldier and later as an acting Sergeant Major in the Canadian Army. He returned to Toronto in 1921 to continue his studies. He was a professional basketball player and used his remuneration from sports to pay his academic fees.

While still an undergraduate, Best became an assistant to Frederick Banting, who was experimenting on pancreatic secretions. By then, it had been established that diabetes involved problems with the pancreas. JJ.R. Macleod, professor of physiology at the University of Toronto, was overseeing the work of Banting and Best. The biochemist James Collip was added to the team later. In 1921, the team succeeded in obtaining the pancreatic extract of insulin in a form that controlled diabetes in dogs, thus paving the way for its trial and usage in human patients. In 1922, the team successfully injected Leonard Thompson, a 14 year-old boy with insulin. He was critical due to diabetes and the injection helped save his life. Banting. Best and Collip shared the patent for insulin, which they sold to the University of Toronto for $1 each.

In 1923, the Nobel Prize Committee honoured Banting and Macleod with the Nobel Prize in Medicine for the discovery of insulin, ignoring Best and Collip. But Banting shared half his prize money with Best, while Macleod did so with Collip. Best continued as research associate in the Banting and Best Department of Medical Research, which was created at the university in 1923.

Picture Credit : Google