Filter by Topic
- People (100) Apply People filter
- Reproduction (88) Apply Reproduction filter
- Publications (70) Apply Publications filter
- Experiments (46) Apply Experiments filter
- Processes (40) Apply Processes filter
- Technologies (37) Apply Technologies filter
- Theories (30) Apply Theories filter
- Legal (29) Apply Legal filter
- Disorders (16) Apply Disorders filter
- Ethics (16) Apply Ethics filter
- Outreach (15) Apply Outreach filter
- Organizations (13) Apply Organizations filter
- Organisms (8) Apply Organisms filter
- Religion (2) Apply Religion filter
- Places (1) Apply Places filter
- Reproductive Health Arizona (1) Apply Reproductive Health Arizona filter
Filter by Format
- (-) Remove Articles filter Articles
Dinosaur Egg Parataxonomy
Dinosaur egg parataxonomy is a classification system that organizes dinosaur eggs by descriptive features such as shape, size, and shell thickness. Though egg parataxonomy originated in the nineteenth century, Zi-Kui Zhao from Beijing, China, developed a modern parataxonomic system in the late twentieth century. Zhao's system, published in 1975, enabled scientists to organize egg specimens according to observable features, and to communicate their findings.
Roy Chapman Andrews (1884-1960)
Roy Chapman Andrews traveled the world studying fossils, from mammals to dinosaurs, during the first half of the twentieth century. Andrews worked and collected fossil specimens for the American Museum of Natural History (AMNH) in New York City, New York. Throughout his career, Andrews collected bones of many animal species, including a previously unknown species of a horned, herbivorous dinosaur, later named Proceratops andrewsi in his honor. Andrews published widely read narratives about his travels and field experiences, such as On the Trail of Ancient Man and Across Mongolian Plains.
Acid Dissolution of Fossil Dinosaur Eggs
Acid dissolution is a technique of removing a fossil from the surrounding rock matrix in which it is encased by dissolving that matrix with acid. Fossilized bone, though strong enough to be preserved for thousands or millions of years, is often more delicate than rock. Once a fossil is discovered, scientists must remove the fossil from its surroundings without damaging the fossil itself.
Hwang Woo-suk's Use of Human Eggs for Research 2002-2005
Hwang Woo-suk, a geneticist in South Korea, claimed in Science magazine in 2004 and 2005 that he and a team of researchers had for the first time cloned a human embryo and that they had derived eleven stem cell lines from it. Hwang was a professor at Seoul National University in Seoul, South Korea. In the Science articles, Hwang stated that all of the women who donated eggs to his laboratory were volunteers who donated their eggs (oocytes) without receiving any compensation in return. In 2006, Hwang admitted that many of the results were fabricated.
Subject: Legal, Ethics, Reproduction
Recombinant Gonadotropins Used in Fertility Treatments
First manufactured in 1988 by Serono laboratories, recombinant gonadotropins are synthetic hormones that can stimulate egg production in women for use in fertility treatments. Recombinant gonadotropins are artificially created using recombinant DNA technology, a technology that joins together DNA from different organisms. In vertebrates, naturally-occurring gonadotropins regulate the growth and function of the gonads, known as testes in males and ovaries in females.
Subject: Technologies, Reproduction
Transvaginal Ultrasound-Guided Oocyte Retrieval
Transvaginal ultrasound-guided oocyte retrieval, also known as egg retrieval, is a surgical technique used by medical professionals to extract mature eggs directly from the women’s ovaries under the guidance of ultrasound imaging. In 1982, physicians Suzan Lenz and Jorgen Lauritsen at the University of Copenhagen in Copenhagen, Denmark, proposed the technology to improve the egg collection aspect of in vitro fertilization, or IVF. During IVF, a healthcare practitioner must remove mature eggs from a woman’s ovaries to fertilize them with sperm outside of the body.
Subject: Technologies, Reproduction
Jan Evangelista Purkyne (1787-1869)
Jan Evangelista Purkyne, also called Johannes or Johann Evangelist Purkinje, studied cells in the cerebellum, fibers of the heart, subjective visual phenomenon, and germinal vesicle, in eastern Europe during the early nineteenth century. His investigations provided insights into various mechanisms and structures of the human body. Purkyne introduced techniques for decalcification of bones and teeth, embedding of tissue specimens, and eye examinations.
History of the Monash IVF Research Program from 1971 to 1989
In 1971, a group of researchers founded the Monash IVF Research Program with the mission to discover how in vitro fertilization, or IVF, techniques could become a treatment for infertility in both men and women. The program included researcher Carl Wood and colleagues John Leeton, Alex Lopata, Alan Trounson, and Ian Johnston at the Queen Victoria Medical Center and Royal Women’s Hospital in Melbourne, Australia. Since the program’s establishment in 1971, the Monash IVF Research Program has helped to develop and implement many IVF technologies still used in clinical practice as of 2020.
Subject: Organizations, Reproduction
"On the Nature of the Process of Fertilization and the Artificial Production of Normal Larvae (Plutei) From the Unfertilized Eggs of the Sea Urchin" (1899), by Jacques Loeb
Jacques Loeb developed procedures to make embryos from unfertilized sea urchin eggs in 1899. Loeb called the procedures "artificial parthenogenesis," and he introduced them and his results in "On the Nature of the Process of Fertilization and the Artificial Production of Norma Larvae (Plutei) from the Unfertilized Eggs of the Sea Urchin" in an 1899 issue of The American Journal of Physiology. In 1900 Loeb elaborated on his experiments.
"Transplantation of Living Nuclei from Blastula Cells into Enucleated Frogs' Eggs" (1952), by Robert Briggs and Thomas J. King
In 1952 Robert Briggs and Thomas J. King published their article, "Transplantation of Living Nuclei from Blastula Cells into Enucleated Frogs' Eggs," in the Proceedings of the National Academy of Sciences, the culmination of a series of experiments conducted at the Institute for Cancer Research and Lankenau Hospital Research Institute in Philadelphia, Pennsylvania. In this paper Briggs and King examined whether nuclei of embryonic cells are differentiated, and by doing so, were the first to conduct a successful nuclear transplantation with amphibian embryos.
“Pregnancy Established in an Infertile Patient After Transfer of a Donated Embryo Fertilized In Vitro” (1983), by Alan Trounson, John Leeton, Mandy Besanko, Carl Wood, and Angelo Conti
In 1983, researchers Alan Trounson, John Leeton, Carl Wood, Mandy Besanko, and Angelo Conti published the article “Pregnancy Established in an Infertile Patient After Transfer of a Donated Embryo Fertilized In Vitro” in The British Medical Journal. In the article, the authors discuss one of the first successful experiments using in vitro fertilization, or IVF, with the use of a human donor embryo at the Monash University and Queen Victoria Medical Center in Melbourne, Australia.
Subject: Publications, Publications, Reproduction, Processes
"The Role of Maternal Mitochondria during Oogenesis, Fertilization and Embryogenesis" (2002), by James M. Cummins
James M Cummins published 'The Role of Maternal Mitochondria during Oogenesis, Fertilization and Embryogenesis' 30 January 2002 in Reproductive BioMedicine Online. In the article, Cummins examines the role of the energy producing cytoplasmic particles, or organelles called mitochondria. Humans inherit mitochondria from their mothers, and mechanisms have evolved to eliminate sperm mitochondria in early embryonic development. Mitochondria contain their own DNA (mtDNA) separate from nuclear DNA (nDNA).
"The Adaptive Significance of Temperature-Dependent Sex Determination in a Reptile" (2008), by Daniel Warner and Richard Shine
In 2008 researchers Daniel Warner and Richard Shine tested the Charnov-Bull model by conducting experiments on the Jacky dragon (Amphibolurus muricatus), in Australia. Their results showed that temperature-dependent sex determination(TSD) evolved in this species as an adaptation to fluctuating environmental temperatures. The Charnov-Bull model, proposed by Eric Charnov and James Bull in 1977, described the evolution of TSD, although the model was, for many years, untested.
Temperature-Dependent Sex Determination in Reptiles
The sex of a reptile embryo partly results from the production of sex hormones during development, and one process to produce those hormones depends on the temperature of the embryo's environment. The production of sex hormones can result solely from genetics or from genetics in combination with the influence of environmental factors. In genotypic sex determination, also called genetic or chromosomal sex determination, an organism's genes determine which hormones are produced.
The Baby Makers (2012)
In 2012, the production company Waddell Media Production released the documentary The Baby Makers. The four-part series, directed and produced by Edel O’Mahony, follows multiple couples in Northern Ireland struggling with infertility problems as they utilize different treatments such as in vitro fertilization, or IVF, egg donation, and egg freezing. IVF is a procedure in which a woman’s egg is fertilized by a sperm outside of her body. Once the sperm fertilizes the egg, a fertility doctor places the fertilized egg back into the woman’s uterus.
"Behavioral Thermoregulation by Turtle Embryos" (2011), by Wei-Guo Du, Bo Zhao, Ye Chen, and Richard Shine
In "Behavioral Thermoregulation by Turtle Embryos," published in Proceedings of the National Academy of Sciences in April, 2011, Wei-Guo Du, Bo Zhao, Ye Chen, and Richard Shine report that turtle embryos can move towards warmer temperatures within the egg when presented with a small, 0.8 degrees Celsius gradient. This behavioral thermoregulation may benefit the embryo's fitness by accelerating the rate of development enough to decrease the incubation period by up to four and a half days. Embryos are generally thought to have little control over their surroundings.
"How do Embryos Assess Risk? Vibrational Cues in Predator-Induced Hatching of Red-Eyed Treefrogs" (2005), by Karen Warkentin
In 'How do Embryos Assess Risk? Vibrational Cues in Predator-Induced Hatching of Red-Eyed Treefrogs' (2005), Karen Warkentin reported on experiments she conducted to see how red-eyed treefrog embryos, Agalychnis callidryas, can distinguish between vibrations due to predator attacks and other environmental occurrences, such as storms. Though the ability of red-eyed treefrogs to alter their hatch timing had been documented, the specific cues that induce early hatching were not well understood.
Subject: Experiments, Organisms
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.
Dr. John Rock, a doctor of obstetrics and gynecology in Boston, and Miriam Menkin, Rock s hired lab technician, were the first researchers to fertilize a human egg outside of a human body in February of 1944. Their work was published on 4 August 1944 in an issue of Science in an article entitled "In Vitro Fertilization and Cleavage of Human Ovarian Eggs." This experiment marked the first time in history that a human embryo was produced outside of the human body, proving that in vitro fertilization was possible in humans.
Subject: Experiments, Reproduction
De Formatione Ovi et Pulli (1621), by Girolamo Fabrici
The embryological treatise De formatione ovi et pulli (On the Formation of the Egg and of the Chick) was written by anatomist and embryologist Girolamo Fabrici and published in Padua posthumously in 1621. The book was edited by Joahannes Prevotius and is separated into two parts that describe Fabrici's observations and assumptions on embryology and combine the traditional knowledge of his predecessors with his own first-hand anatomical observations.
Oviraptor philoceratops Dinosaurs
Oviraptor philoceratops was a small bird-like dinosaur that lived about seventy-five million years ago, during the late Cretaceous period. In 1923, George Olsen of the American Museum of Natural History (AMNH) in New York City, New York, discovered the first Oviraptor fossilized skeleton on top of a dinosaur egg nest in the Gobi Desert, Mongolia. Because of the close proximity of dinosaur and nest, when Henry Fairfield Osborn president of the AMNH published on the discovery, he assumed that the Oviraptor had died attempting to steal the eggs.
Experiments on the Reproductive Costs of a Pure Capital Breeder, the Children’s Python (Antaresia childreni) (2013), by Olivier Lourdais, Sophie Lorioux, and Dale F. DeNardo
In 2013, Olivier Lourdais, Sophie Lorioux, and Dale DeNardo conducted a study on the impact of the reproductive effort on the muscle size and the constriction strength of female Children’s pythons. Children’s pythons are pure capital breeders, meaning that they do not eat during vitellogenesis, a process in which egg-laying or oviparous species allocate bodily resources including fat, water, and protein to follicles in the ovary that develop into eggs.
Study of Fossilized Massospondylus Dinosaur Embryos from South Africa (1978-2012)
In 1978, James Kitching discovered two dinosaur embryos in a road-cut talus at Roodraai (Red Bend) in Golden Gate Highlands National Park, South Africa. Kitching assigned the fossilized embryos to the species of long necked herbivores Massospondylus carinatus (longer vertebra) from the Early Jurassic period, between 200 and 183 million years ago. The embryos were partially visible but surrounded by eggshell and rock, called matrix. Kitching said that the eggs were too delicate to remove from the matrix without damage.
In humans, multi-fetal pregnancy occurs when a mother carries more than one fetus during the pregnancy. The most common multi-fetal pregnancy is twins, but mothers have given birth to up to eight children (octuplets) from a single pregnancy. Multiple fetusus can result from the release of multiple eggs or multiple ovulations, the splitting of a single fertilized egg, and fertility treatments such as in vitro fertilization (IVF) which involves the insertion of many fertilized eggs into the mother's uterus.
Subject: Processes, Reproduction
An Atlas of Fertilization and Karyokinesis of the Ovum (1895), by Edmund Beecher Wilson
Edmund Beecher Wilson in the US published An Atlas of Fertilization and Karyokinesis of the Ovum (hereafter called An Atlas) in 1895. The book presents photographs by photographer Edward Leaming that capture stages of fertilization, the fusion of sperm and egg and early development of sea urchin (Toxopneustes variegatus) ova, or egg cell. Prior to An Atlas, no one photographed of eggcell division in clear detail. Wilson obtained high quality images of egg cells by cutting the cells into thin sections and preserving them throughout different stages of development.
Subject: Publications, Reproduction