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"On the Induction of Embryonic Primordia by Implantation of Organizers from Different Species" (1924), Hilde Mangold's Dissertation

Hilde Proscholdt Mangold was a doctoral student at the Zoological Institute at the University of Freiburg in Freiburg, Germany, from 1920-1923. Mangold conducted research for her dissertation 'On the Induction of Embryonic Primordia by Implantation of Organizers from Different Species' ('Ueber Induktion von Embryonanlagen durch Implantation artfremder Organisatoren'), under the guidance of Hans Spemann, a professor of zoology at the University of Freiburg.

Format: Articles

Subject: Experiments, Publications

"CRISPR /Cas9-mediated Gene Editing in Human Tripronuclear Zygotes" (2015), by Junjiu Huang et al.

In 2015, Junjiu Huang and his colleagues reported their attempt to enable CRISPR/cas 9-mediated gene editing in nonviable human zygotes for the first time at Sun Yat-Sen University in Guangzhou, China. Their article, CRISPR /Cas9-mediated Gene Editing in Human Tripronuclear Zygotes, was published in Protein and Cell. Nonviable zygotes are sperm-fertilized eggs that cannot develop into a fetus. Researchers previously developed the CRISPR/cas 9 gene editing tool, which is a system that originated from bacteria as a defense mechanism against viruses.

Format: Articles

Subject: Publications, Experiments

"The Effects of Wing Bud Extirpation on the Development of the Central Nervous System in Chick Embryos" (1934), by Viktor Hamburger

German embryologist Viktor Hamburger came to the US in 1932 with a fellowship provided by the Rockefeller Foundation. Hamburger started his research in Frank Rattray Lillie's laboratory at the University of Chicago. His two-year work on the development of the central nervous system (CNS) in chick embryos was crystallized in his 1934 paper, "The Effects of Wing Bud Extirpation on the Development of the Central Nervous System in Chick Embryos," published in The Journal of Experimental Zoology.

Format: Articles

Subject: Publications, Experiments

Lysogenic Bacteria as an Experimental Model at the Pasteur Institute (1915-1965)

Lysogenic bacteria, or virus-infected bacteria, were the primary experimental models used by scientists working in the laboratories of the Pasteur Institute in Paris, France, during the 1950s and 1960s. Historians of science have noted that the use of lysogenic bacteria as a model in microbiological research influenced the scientific achievements of the Pasteur Institute's scientists.

Format: Articles

Subject: Organisms, Experiments

"Generation of Induced Pluripotent Stem Cells without Myc from Mouse and Human Fibroblasts" (2007), by Masato Nakagawa et al.

In November 2007, Masato Nakagawa, along with a number of other researchers including Kazutoshi Takahashi, Keisuke Okita, and Shinya Yamanaka, published "Generation of Induced Pluripotent Stem Cells without Myc from Mouse and Human Fibroblasts" (abbreviated "Generation") in Nature. In "Generation," the authors point to dedifferentiation of somatic cells as an avenue for generating pluripotent stem cells useful for treating specific patients and diseases.

Format: Articles

Subject: Publications, Experiments

“Survival of Mouse Embryos Frozen to -196 ° and -269 °C” (1972), by David Whittingham, Stanley Leibo, and Peter Mazur

In 1972, David Whittingham, Stanley Leibo, and Peter Mazur published the paper, “Survival of Mouse Embryos Frozen to -196 ° and -269 °C,” hereafter, “Survival of Mouse Embryos,” in the journal Science. The study marked one of the first times that researchers had successfully cryopreserved, or preserved and stored by freezing, a mammalian embryo and later transferred that embryo to a live mouse who gave birth to viable offspring. Previously, scientists had only been successful cryopreserving single cells, like red blood cells.

Format: Articles

Subject: Experiments, Publications

"Programmed Cell Death-II. Endocrine Potentiation of the Breakdown of the Intersegmental Muscles of Silkmoths" (1964), by Richard A. Lockshin and Carroll M. Williams

Richard A. Lockshin's 1963 PhD dissertation on cell death in insect metamorphosis was conducted under the supervision of Harvard insect physiologist Carroll M. Williams. Lockshin and Williams used this doctoral research as the basis for five articles, with the main title "Programmed Cell Death," that were published between 1964 and 1965 in the Journal of Insect Physiology. These articles examine the cytological processes, neuronal and endocrinal controls, and the influence of drugs on the mechanism of cell death observed in pupal muscle structures of the American silkmoth.

Format: Articles

Subject: Experiments, Publications

Beadle and Ephrussi Show that Something Besides Eye Tissue Determines Eye Color in Fruit Flies

In the 1930s, George Beadle and Boris Ephrussi discovered factors that affect eye colors in developing fruit flies. They did so while working at the California Institute of Technology in Pasadena, California. (1) They took optic discs (colored fuchsia in the image) from fruit fly larvae in the third instar stage of development. Had the flies not been manipulated, they would have developed into adults with vermilion eyes.

Format: Graphics

Subject: Experiments, Organisms

Beadle and Ephrussi’s Technique to Transplant Optic Discs between Fruit Fly Larvae

In 1935, George Beadle and Boris Ephrussi developed a technique to transplant optic discs between fruit fly larvae. They developed it while at the California Institute of Technology in Pasedena, California. Optic discs are tissues from which the adult eyes develop. Beadle and Ephrussi used their technique to study the development of the eye and eye pigment. (1) The experimenter dissects a donor larva, which is in the third instar stage of development, and removes the optic disc (colored red) with a micropipette.

Format: Graphics

Subject: Technologies, Experiments, Organisms

Gastrulation in Mus musculus (common house mouse)

As mice embryos develop, they undergo a stage of development called gastrulation. The hallmark of vertebrate gastrulation is the reorganization of the inner cell mass (ICM) into the three germ layers: ectoderm, mesoderm, and endoderm. Mammalian embryogenesis occurs within organisms; therefore, gastrulation was originally described in species with easily observable embryos. For example, the African clawed frog (Xenopus laevis) is the most widely used organism to study gastrulation because the large embryos develop inside a translucent membrane.

Format: Articles

Subject: Processes, Experiments

Thesis: Timeline of Changes in Mammography Guidelines in the United States

Breast cancer affects about 12% of women in the US. Arguably, it is one of the most advertised cancers. Mammography became a popular tool of breast cancer screening in the 1970s, and patient-geared guidelines came from the American Cancer Society (ACS) and the US Preventative Task Force (USPSTF). This research focuses on ACS guidelines, as they were the earliest as well as the most changed guidelines. Mammography guidelines changed over time due to multiple factors. This research has tracked possible causes of those changes.

Format: Essays and Theses

Subject: Technologies, Experiments, Publications

The Inheritance of Acquired Characteristics (1924), by Paul Kammerer

The Inheritance of Acquired Characteristics is a book published in 1924, written by Paul Kammerer, who studied developmental biology in Vienna, Austria, in the early twentieth century. The Inheritance of Acquired Characteristics summarizes Kammerer's experiments, and explains their significance. In his book, Kammerer aims to explain how offspring inherit traits from their parents. Some scholars criticized Kammerer's reports and interpretations, arguing that they were inaccurate and misleading, while others supported Kammerer's work.

Format: Articles

Subject: Publications, Theories

Paul Kammerer (1880-1926)

Paul Kammerer conducted experiments on amphibians and marine animals at the Vivarium, a research institute in Vienna, Austria, in the early twentieth century. Kammerer bred organisms in captivity, and he induced them to develop particular adaptations, which Kammerer claimed the organismss offspring would inherit. Kammerer argued that his results demonstrated the inheritance of acquired characteristics, or Lamarckian inheritance. The Lamarckian theory of inheritance posits that individuals transmit acquired traits to their offspring.

Format: Articles

Subject: Experiments, People

The First Successful Cloning of a Gaur (2000), by Advanced Cell Technology

The first successful cloning of a gaur in 2000 by Advanced Cell Technology involved the cells of two animals: an egg cell from a domestic cow and a skin cell from a gaur. The researchers extracted the egg cell from the ovary of the domestic cow and the skin cell from the skin of the gaur. First, the researchers performed nuclear transplantation on the egg cell of the cow, during which they removed the nucleus of the egg cell. The mitochondria of the egg cell remained intact inside the cell.

Format: Graphics

Subject: Experiments, Organisms, Reproduction

Oral Glucose Tolerance Test for Gestational Diabetes

In the twentieth century, researchers developed the oral glucose tolerance test, or OGTT, as a method to diagnose different types of diabetes, a medical condition that causes blood sugar levels to become abnormally high. During the test, a healthcare provider measures a person’s blood sugar levels before and after the person consumes a predetermined amount of glucose solution. While not exclusively used for pregnant women, an OGTT may test for gestational diabetes which, according to the International Diabetes Federation, affected one in six pregnancies worldwide in 2019.

Format: Articles

Subject: Technologies, Reproduction, Experiments

James Edgar Till (1931– )

James Edgar Till is a biophysicist known for establishing the existence of stem cells along with Ernest McCulloch in 1963. Stem cells are undifferentiated cells that can shift, or differentiate, into specialized types of cells and serve as a repair system in the body by dividing indefinitely to replenish other cells. Till’s work with stem cells in bone marrow, which produces the body’s blood cells, helped form the field of modern hematology, a medical discipline that focuses on diseases related to the blood.

Format: Articles

Subject: People, Experiments, Technologies

"The Development of the Pronephros during the Embryonic and Early Larval Life of the Catfish (Ictalurus punctatus)" (1932), by Rachel L. Carson

Rachel L. Carson studied biology at Johns Hopkins University in Maryland and graduated in 1933 with an MA upon the completion of her thesis, The Development of the Pronephros during the Embryonic and Early Larval Life of the Catfish (Ictalurus punctatus). The research that Carson conducted for this thesis project grounded many of the claims and observations she presented in her 1962 book, Silent Spring.

Format: Articles

Subject: People, Experiments, Publications

Eduard Friedrich Wilhelm Pflüger (1829-1910)

Eduard Friedrich Wilhelm Pflüger was a physiologist known for his research on respiration, the respiratory quotient, experimenting on the effects of electricity on muscles and nerves, and his study of the ovaries and egg development. His experiments on how the gravitational orientation of frog eggs affects their cleavage plane inspired embryologists such as Wilhelm Roux and Gustav Born to conduct their own experiments using frog eggs.

Format: Articles

Subject: People

Chemical Induction

Research in chemical induction seeks to identify the compound or compounds responsible for differentiation in a developing embryo. Soren Lovtrup compared the search for these compounds to the search for the philosopher's stone. It was based on the assumption that the differentiating agents have to be chemical substances either within cells or in the extracellular matrix.

Format: Articles

Subject: Processes

Otto Rank (1884–1939)

Otto Rank studied how birth impacts individuals’ psychology and creates anxiety throughout their lives in Europe and the US during the nineteenth century. In his book The Trauma of Birth, Rank stated that birth was extremely traumatic and that one spent his or her whole life trying to recover from the experience of being born and harshly separated from the peaceful womb. He argued that the trauma experienced at birth is the source of all human suffering and the key to understanding anxiety later in life.

Format: Articles

Subject: People

Thesis: How Purported Scientific Failures Have Led to Advancements in IVF

This thesis shows us the history of how some of the first attempts at IVF in humans using various options such as donated egg cells and cryopreserved embryos, often ended in early miscarriages. At that time, most members of the scientific community and general public responded to those trials by regarding them as insignificant. In 1998, the success rate of women under the age of 38 having children with the use of IVF was 22.1%. Over time, scientists began to acknowledge those published findings that detailed various “failed” human IVF experiments.

Format: Essays and Theses

Subject: Publications, Technologies, Experiments, Reproduction, Outreach

HeLa Cell Line

The HeLa cell line was the first immortal human cell line that George Otto Gey, Margaret Gey, and Mary Kucibek first isolated from Henrietta Lacks and developed at The Johns Hopkins Hospital in Baltimore, Maryland, in 1951. An immortal human cell line is a cluster of cells that continuously multiply on their own outside of the human from which they originated. Scientists use immortal human cell lines in their research to investigate how cells function in humans.

Format: Articles

Subject: Technologies, Experiments, People, Ethics

Johann Gregor Mendel (1822-1884)

Johann Gregor Mendel studied plants and their patterns of inheritance in Austria during the nineteenth century. Mendel experimented with the pea plant, Pisum, and his publication, 'Versuche uber Pflanzenhybriden' (“Experiments on Plant Hybridization”), published in 1866, revolutionized theories of trait inheritance. Mendel’s discoveries relating to factors, traits, and how they pass between generations of organisms enabled scientists in the twentieth century to build theories of genetics.

Format: Articles

Subject: People

Ernest Everett Just (1883-1941)

Ernest Everett Just was an early twentieth century American experimental embryologist involved in research at the Marine Biological Laboratory (MBL) at Woods Hole, Massachusetts, and the Stazione Zoologica in Naples, Italy. Just was known for simple but elegant experiments that supported the "fertilizing" theory of Frank R. Lillie and served as an antagonist to Jacques Loeb's work with artificial parthenogenesis.

Format: Articles

Subject: People

Anne Laura Dorinthea McLaren (1927-2007)

Anne Laura Dorinthea McLaren was a developmental biologist known for her work with embryology in the twentieth century. McLaren was the first researcher to grow mouse embryos outside of the womb. She experimented by culturing mouse eggs and successfully developing them into embryos, leading to advancements with in vitro fertilization.

Format: Articles

Subject: People