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Induced Pluripotent Stem Cell Experiments by Kazutoshi Takahashi and Shinya Yamanaka in 2006 and 2007

In 2006, Kazutoshi Takahashi and Shinya Yamanaka reprogrammed mice fibroblast cells, which can produce only other fibroblast cells, to become pluripotent stem cells, which have the capacity to produce many different types of cells. Takahashi and Yamanaka also experimented with human cell cultures in 2007. Each worked at Kyoto University in Kyoto, Japan. They called the pluripotent stem cells that they produced induced pluripotent stem cells (iPSCs) because they had induced the adult cells, called differentiated cells, to become pluripotent stem cells through genetic manipulation.

Format: Articles

Subject: Experiments

Somatic Cell Nuclear Transfer in Mammals (1938-2013)

In the second half of the
twentieth century, scientists learned how to clone organisms in some
species of mammals. Scientists have applied somatic cell nuclear transfer to clone human and
mammalian embryos as a means to produce stem cells for laboratory
and medical use. Somatic cell nuclear transfer (SCNT) is a technology applied in cloning, stem cell
research and regenerative medicine. Somatic cells are cells that
have gone through the differentiation process and are not germ
cells. Somatic cells donate their nuclei, which scientists

Format: Articles

Subject: Theories, Technologies, Processes

Effects of Prenatal Alcohol Exposure on Basal Ganglia Development

Prenatal exposure to alcohol (ethanol) in human and animal models results in a range of alcohol-induced developmental defects. In humans, those collective birth defects are called Fetal Alcohol Spectrum Disorders, with the most severe manifestation being Fetal Alcohol Syndrome (FAS). FAS is defined by pre- and post-natal growth retardation, minor facial abnormalities, and deficiencies in the central nervous system (CNS). The basal ganglia, one of the central nervous system components, are affected by exposure to ethanol during development.

Format: Articles

Subject: Disorders, Reproduction

Ernst Heinrich Philipp August Haeckel (1834-1919)

Ernst Heinrich Philipp August Haeckel was a prominent comparative anatomist and active lecturer in the late nineteenth and early twentieth centuries. He is most well known for his descriptions of phylogenetic trees, studies of radiolarians, and illustrations of vertebrate embryos to support his biogenetic law and Darwin's work with evolution. Haeckel aggressively argued that the development of an embryo repeats or recapitulates the progressive stages of lower life forms and that by studying embryonic development one could thus study the evolutionary history of life on earth.

Format: Articles

Subject: People

John von Neumann's Cellular Automata

Cellular automata (CA) are mathematical models used to simulate complex systems or processes. In several fields, including biology, physics, and chemistry, CA are employed to analyze phenomena such as the growth of plants, DNA evolution, and embryogenesis. In the 1940s John von Neumann formalized the idea of cellular automata in order to create a theoretical model for a self-reproducing machine. Von Neumann's work was motivated by his attempt to understand biological evolution and self-reproduction.

Format: Articles

Subject: Theories

"A molecular wound response program associated with regeneration initiation in planarians" (2012), by Danielle Wenemoser et al.

In 2012, a team of scientists across the US conducted an experiment to find the mechanism that allowed a group of flatworms, planarians, to regenerate any body part. The group included Danielle Wenemoser, Sylvain Lapan, Alex Wilkinson, George Bell, and Peter Reddien. They aimed to identify genes that are expressed by planarians in response to wounds that initiated a regenerative mechanism. The researchers determined several genes as important for tissue regeneration.

Format: Articles

Subject: Experiments

Ian Wilmut (1944- )

British embryologist Sir Ian Wilmut, best known for his work in the field of animal genetic engineering and the successful cloning of sheep, was born 7 July 1944 in Hampton Lucy, England. The family later moved to Scarborough, in the north of the country, to allow his father to accept a teaching position. There Wilmut met Gordon Whalley, head of the biology department at Scarborough High School for Boys, which Wilmut attended.

Format: Articles

Subject: People

Nuclear Transplantation

Nuclear transplantation is a method in which the nucleus of a donor cell is relocated to a target cell that has had its nucleus removed (enucleated). Nuclear transplantation has allowed experimental embryologists to manipulate the development of an organism and to study the potential of the nucleus to direct development. Nuclear transplantation, as it was first called, was later referred to as somatic nuclear transfer or cloning.

Format: Articles

Subject: Processes

Robert William Briggs (1911-1983)

Robert William Briggs was a prolific developmental biologist. However, he is most identified with the first successful cloning of a frog by nuclear transplantation. His later studies focused on the problem of how genes influence development.

Format: Articles

Subject: People

Viktor Hamburger (1900-2001)

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.

Format: Articles

Subject: People

San Diego Zoo Institute for Conservation Research

The San Diego Zoo Institute for Conservation Research (SDZICR) in San Diego, California, is a research organization that works to generate, use, and share information for the conservation of wildlife and their habitats. In 1975, Kurt Benirschke, a researcher at the University of California, San Diego (UCSD) who studied human and animal reproduction, and Charles Bieler, the director of the San Diego Zoo, collaborated to form the Center for Reproduction of Endangered Species (CRES).

Format: Articles

Subject: Organizations

The Role of the Notch signaling pathway in Somitogenesis

Among other functions, the Notch signaling pathway contributes to the development of somites in animals. It involves a cell signaling mechanism with a wide range of functions, including cellular differentiation, and the formation of the embryonic structures (embryogenesis). All multicellular animals use Notch signaling, which is involved in the development, maintenance, and regeneration of a range of tissues. The Notch signaling pathways spans two cells, and consists of receptor proteins, which cross one cell's membrane and interacts with proteins on adjacent cells, called ligands.

Format: Articles

Subject: Theories, Processes

Barbara McClintock (1902-1992)

Barbara McClintock worked on genetics in corn (maize) plants and spent most of her life conducting research at the Cold Spring Harbor Laboratory in Laurel Hollow, New York. McClintock's research focused on reproduction and mutations in maize, and described the phenomenon of genetic crossover in chromosomes. Through her maize mutation experiments, McClintock observed transposons, or mobile elements of genes within the chromosome, which jump around the genome. McClintock received the Nobel Prize for Physiology or Medicine in 1983 for her research on chromosome transposition.

Format: Articles

Subject: People

Purkinje Cells

Purkinje cells, also called Purkinje neurons, are neurons in vertebrate animals located in the cerebellar cortex of the brain. Purkinje cell bodies are shaped like a flask and have many threadlike extensions called dendrites, which receive impulses from other neurons called granule cells. Each cell also has a single projection called an axon, which transmits impulses to the part of the brain that controls movement, the cerebellum. Purkinje cells are inhibitory neurons: they secrete neurotransmitters that bind to receptors that inhibit or reduce the firing of other neurons.

Format: Articles

Subject: Theories

“Use of reproductive technology for sex selection for nonmedical reasons” (2015), by the Ethics Committee of the American Society for Reproductive Medicine

In June 2015, the Ethics Committee of the American Society for Reproductive Medicine, or ASRM, published “Use of reproductive technology for sex selection for nonmedical reasons” in Fertility and Sterility. In the report, the Committee presents arguments for and against the use of reproductive technology for sex selection for any reason besides avoiding sex-linked disorders, or genetic disorders that only affect a particular sex.

Format: Articles

Subject: Publications

Johns Hopkins Fertility Center

Johns Hopkins Medical Center, located in Baltimore, Maryland, opened in 1889; its associated medical school opened four years later. Today the hospital, a leading research center, contains many departments, including a fertility center that is renowned for taking on difficult cases that have been rejected by other fertility clinics. The fertility center was founded by physician Georgeanna Seegar Jones in 1939 as the Division of Reproductive Endocrinology in the gynecology department. The division expanded once formal training in reproductive endocrinology began in 1973.

Format: Articles

Subject: Organizations, Reproduction

Jan Swammerdam (1637-1680)

Jan Swammerdam, known as the founder of the preformation theory based on his extensive research on insect development, was born on 12 February 1637 in Amsterdam, the Netherlands, to Baertje Jans Corvers and Jan Jacobszoon Swammerdam. He began medical school on 11 October 1661 at the University of Leiden. A few of his classmates included Regnier de Graaf, Frederik Ruysch, Niels Stensen (Nicolaus Steno), and Robertus Padtbrugge. Padtbrugge would later join the East India Company and send Swammerdam exotic animals.

Format: Articles

Subject: People

Reassessment of Carrel's Immortal Tissue Culture Experiments

In the 1910s, Alexis Carrel, a French surgeon and biologist, concluded that cells are intrinsically immortal. His claim was based on chick-heart tissue cultures in his laboratory that seemed to be able to proliferate forever. Carrel's ideas about cellular immortality convinced his many contemporaries that cells could be maintained indefinitely. In the 1960s, however, Carrel's thesis about cell immortality was put into question by the discovery that human diploid cells can only proliferate for a finite period.

Format: Articles

Subject: Processes, Theories

The Jackson Laboratory

The Roscoe B. Jackson Laboratory, known commonly in the scientific field as the Jackson Laboratory, was founded by Clarence Cook Little in May 1929. The lab has been pivotal in research with in vitro fertilization, teratomas, gene replacement therapy for birth defects, and more because its researchers have focused from the beginning on developing the mouse as a model organism. Mice were chosen by researchers at Jackson as the best available model for genetic research, and today genetically uniform strains of mice developed at the lab are used in laboratories all over the world.

Format: Articles

Subject: Organizations

Charles Manning Child (1869-1954)

Born in Ypsilanti, Michigan, on 2 February 1869, Charles Manning Child was the only surviving child of Mary Elizabeth and Charles Chauncey Child, a prosperous, old New England family. Growing up in Higganum, Connecticut, Child was interested in biology from an early age. He made extensive collections of plants and minerals on his family farm and went on to study biology at Wesleyan University, commuting from his family home. Child received his PhB in 1890 and MS in biology in 1892, and then went on to study in Leipzig after his parents death.

Format: Articles

Subject: People

Mitochondrial DNA (mtDNA)

Mitochondrial DNA (mtDNA) is located outside the nucleus in the liquid portion of the cell (cytoplasm) inside cellular organelles called Mitochondria. Mitochondria are located in all complex or eukaryotic cells, including plant, animal, fungi, and single celled protists, which contain their own mtDNA genome. In animals with a backbone, or vertebrates, mtDNA is a double stranded, circular molecule that forms a circular genome, which ranges in size from sixteen to eighteen kilo-base pairs, depending on species. Each mitochondrion in a cell can have multiple copies of the mtDNA genome.

Format: Articles

Subject: Theories

“An Extended Family with a Dominantly Inherited Speech Disorder” (1990), by Jane A. Hurst et al.

In 1990, researcher Jane Hurst and her colleagues published “An Extended Family With a Dominantly Inherited Speech Disorder,” in which they proposed that a single gene was responsible for a language disorder across three generations of a family. Affected individuals of the family, called the KE family, had difficulty producing, expressing and comprehending speech. Hurst and her team studied the KE family and the disorder at the Department of Clinical Genetics at the Great Ormond Street Hospital for Children in London, England.

Format: Articles

Subject: Publications, Disorders

Apoptosis in Embryonic Development

Apoptosis, or programmed cell death, is a mechanism in embryonic development that occurs naturally in organisms. Apoptosis is a different process from cell necrosis, which is uncontrolled cell death usually after infection or specific trauma. As cells rapidly proliferate during development, some of them undergo apoptosis, which is necessary for many stages in development, including neural development, reduction in egg cells (oocytes) at birth, as well as the shaping of fingers and vestigial organs in humans and other animals. Sydney Brenner, H. Robert Horvitz, and John E.

Format: Articles

Subject: Theories

Calvin Blackman Bridges (1889-1938)

Calvin Blackman Bridges studied chromosomes and heredity in the US throughout the early twentieth century. Bridges performed research with Thomas Hunt Morgan at Columbia University in New York City, New York, and at the California Institute of Technology in Pasadena, California. Bridges and Morgan studied heredity in Drosophila, the common fruit fly. Throughout the early twentieth century, researchers were gathering evidence that genes, or what Gregor Mendel had called the factors that control heredity, are located on chromosomes.

Format: Articles

Subject: People

Meiosis in Humans

Meiosis, the process by which sexually-reproducing organisms generate gametes (sex cells), is an essential precondition for the normal formation of the embryo. As sexually reproducing, diploid, multicellular eukaryotes, humans rely on meiosis to serve a number of important functions, including the promotion of genetic diversity and the creation of proper conditions for reproductive success.

Format: Articles

Subject: Processes, Reproduction