Embryo Project Encyclopedia

Stanley Cohen published "Purification of a Nerve-Growth Promoting Protein from the Mouse Salivary Gland and its Neuro-Cytoxic Antiserum" in the Proceedings of the National Academies of Sciences in 1960. This paper outlined the successful purification and identification of nerve growth factor (NGF) as a protein, the developmental effects of depriving an embryo of NGF, and the discovery that NGF is also required for the maintenance of the nervous system.

The epigenetic landscape is a concept representing embryonic development. It was proposed by Conrad Hal Waddington to illustrate the various developmental pathways a cell might take toward differentiation. The epigenetic landscape integrates the connected concepts of competence, induction, and regulative abilities of the genes into a single model designed to explain cellular differentiation, a long standing problem in embryology.

Rita Levi-Montalcini is a Nobel Laureate recognized for her work in the discovery and characterization of nerve growth factor. Nerve growth factor (NGF) promotes the growth and maintenance of the nervous system in a developing system. The majority of her career has been devoted to investigating the many aspects of NGF.

Nerve growth factor (NGF) is a signaling protein and growth factor implicated in a wide range of development and maintenance functions. NGF was discovered through a series of experiments in the 1950s on the development of the chick nervous system. Since its discovery, NGF has been found to act in a variety of tissues throughout development and adulthood. It has been implicated in immune function, stress response, nerve maintenance, and in neurodegenerative diseases. It is named for its effect on the critical role it plays in the growth and organization of the nervous system during embryonic development.

As one of the first to work at the Carnegie Institution of Washington Department of Embryology, Warren Harmon Lewis made a number of contributions to the field of embryology. In addition to his experimental discoveries on muscle development and the eye, Lewis also published and revised numerous works of scientific literature, including papers in the Carnegie Contributions to Embryology and five editions of Gray's Anatomy.

Jane Marion Oppenheimer, embryologist and historian of science and medicine, was born on 19 September 1911 in Philadelphia, Pennsylvania, to Sylvia Stern and James H. Oppenheimer. After studying zoology at Bryn Mawr College, Oppenheimer received her AB degree in 1932. Oppenheimer received her PhD in embryology at Yale University in 1935 and worked as a research fellow from 1935-1936. While at Yale she was influenced by the work of Ross Granville Harrison and John Spangler Nicholas, the latter of whom was Oppenheimer's PhD advisor. While working with Nicholas, she studied the embryology of killifish (Fundulus hereoclitus) using Nicholas s method for dechorionating the embryo, which made it possible to perform precise experimental manipulations on teleost embryos. Oppenheimer became interested in teleosts after studying the history of biology as a graduate student and published a part of her dissertation, "Historical Introduction to the Study of Teleostean Development," in the History of Science Society journal Osiris. From 1934-1937 she published numerous noteworthy papers discussing Fundulus embryology. Oppenheimer performed fate mapping experiments and developed a staging series for Fundulus embryos. When the United States and the USSR developed Apollo-Soyuz as a joint space venture, Oppenheimer used Fundulus embryos to design an experiment that tested the effects of a zero-gravity environment on embryonic development.

Viktor Hamburger was an embryologist who focused on neural development. His scientific career stretched from the early 1920s as a student of Hans Spemann to the late 1980s at Washington University resolving the role of nerve growth factor in the life of neurons. Hamburger is noted for his systematic approach to science and a strict attention to detail. Throughout his life he maintained an interest in nature and the arts, believing both were important to his scientific work.

Washington University in St. Louis served as the backdrop for many scientific discoveries, including that of nerve growth factor (NGF). Many of the accomplishments in embryology at Washington University can be attributed to the influence of Viktor Hamburger. He served as chair of the zoology department for twenty-five years. One of the few Nobel Prizes given for embryological research was awarded to faculty members Hamburger hired; Rita Levi-Montalcini and Stanley Cohen won for their role in the discovery of nerve growth factor.

The hanging drop tissue culture is a technique utilized in embryology and other fields to allow growth that would otherwise be restricted by the flat plane of culture dishes and also to minimize the surface area to volume ratio, slowing evaporation. The classic hanging drop culture is a small drop of liquid, such as plasma or some other media allowing tissue growth, suspended from an inverted watch glass. The hanging drop is then suspended by gravity and surface tension, rather than spreading across a plate. This allows tissues or other cell types to be examined without being squashed against a dish.

Pope Pius XI, born Ambrogio Damiano Achille Ratti, was born to the wealthy owner of a silk factory on 31 May 1857 in Desio, Italy. He was ordained to the priesthood at the age of eighteen, at which time he began a long life devoted to study, peacekeeping, and the betterment of societies around the world. Pius XI is noted here for his contribution to the Roman Catholic Church's early twentieth century approach to issues regarding contraception and abortion, which was presented in his December 1930 encyclical "Casti Connubii."