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  • sperm
  • Embryo development begins with a sperm fertilizing an egg to become a zygote which undergoes many cleavages to develop into a ball of cells called a morula. (wikipedia.org)
  • At this point, the question may be raised as to how an embryo is created without a sperm uniting with the egg. (cbhd.org)
  • In the normal process of fertilization and embryo formation, the egg and sperm cells each have only one copy, or half, of the DNA necessary to code for a fully functioning human being. (cbhd.org)
  • At the point of union of the sperm and egg, an embryo is created. (cbhd.org)
  • According to the definitions included in the bill, Clone a human being or cloning a human being, shall mean the creation of a human being by any means other than by the fertilization of a naturally intact oocyte of a human female by a naturally intact sperm of a human male. (natcath.org)
  • When the sperm fertilizes the egg, the sperm nucleus and centrosomes are deposited within the egg, which causes a cytoplasmic flux resulting in the movement of the sperm pronucleus and centrosomes towards one pole. (wikipedia.org)
  • The centrosomes deposited by the sperm seem to be responsible for the establishment of the posterior pole within the one cell embryo. (wikipedia.org)
  • Xenopus
  • In many animals such as Drosophila and Xenopus, the mid blastula transition (MBT) is a crucial step in development during which the maternal mRNA is degraded and control over development is passed to the embryo. (wikipedia.org)
  • In Xenopus embryos, the blastula is composed of three different regions. (wikipedia.org)
  • zygote
  • When this is done the cytoplasmic factors effect the nucleus to become a zygote. (wikipedia.org)
  • These proteins are initially distributed uniformly throughout the zygote and then become polarized with the creation of the posterior pole. (wikipedia.org)
  • Since the zygote is genetically identical to the embryo, the fully formed fetus, and the baby, questioning the beginning of personhood could lead to an instance of the Sorites paradox, also known as the paradox of the heap. (wikipedia.org)
  • fetal
  • In January 2018, a team of scientists in Shanghai announced the successful cloning of two female crab-eating macaques (named Zhong Zhong and Hua Hua) from fetal nuclei. (wikipedia.org)
  • The issue arises in a number of fields including science, religion, philosophy, and law, and is most acute in debates relating to abortion, stem cell research, reproductive rights, and fetal rights. (wikipedia.org)
  • vertebrate
  • In the vertebrate embryo, a rhombomere is a transiently divided segment of the developing neural tube, within the hindbrain region (a neuromere) in the area that will eventually become the rhombencephalon. (wikipedia.org)
  • connective
  • In her work with chick embryos, Margaret Lewis studied connective tissue formation within the tissues as well as outside of an environment where factors involved in coagulation are present. (wikipedia.org)
  • Platt observed that in the mudpuppy (Necturus maculosus), the coordinated migration of neural crest cells in the embryo produced parts of the nervous system, bones, and connective tissues in the head. (asu.edu)
  • therapeutic
  • Along the way we must reduce the emotional valence of phrases such as "therapeutic cloning" and "destruction of embryos. (jci.org)
  • Given the spin that science and the media have put on the latest achievement in medical science - the cloning of the first human embryo - some reading this article may truly believe that there are good, and even therapeutic, reasons for human cloning and that human cloning cannot really result in the development of a human being to the point of birth. (cbhd.org)
  • The House rejected competing measures that would have banned cloning for reproductive purposes while allowing nonreproductive or therapeutic cloning for scientific research. (encyclopedia.com)
  • Stem cells can then be obtained by the destruction of this clone embryo for use in therapeutic cloning or in the case of reproductive cloning the clone embryo is implanted into a host mother for further development and brought to term. (wikipedia.org)
  • cells
  • Changes in dendrite-mediated interaction between nerve cells can contribute to the formation of new memories. (pewtrusts.org)
  • In this video article, we describe our technique for targeted laser ablation of kidney nephron cells in the zebrafish embryo kidney, or pronephros. (jove.com)
  • In this issue of Celebrate Life, I will explain embryonic stem cell technology, where the stem cells are derived, in a variation of ways, from the developing human embryo. (clmagazine.org)
  • The resultant embryo grows for the next five days to a blastocyst, which is a hollow ball of around 120 cells with a concentration of cells at one pole called the inner cell mass. (clmagazine.org)
  • The embryologist uses micro-instruments to dissect the inner cell mass from the rest of the embryo and the cells are then disaggregated and placed on top of further "feeder cells" (usually of animal origin) in another dish. (clmagazine.org)
  • Scheme of the formation of embryo cells of cereals with the base chromosome numbers multiple of "7" at the initial stage of development, with the critical number of 588 cells. (intechopen.com)
  • The arrows in a circle indicate the direction of flows, the shaded rectangles - the location of the cells, and the shape of the envelope lines around the perimeter of the shaded rectangles - the shape of the embryo. (intechopen.com)
  • The first, by Drs. Donald Landry and Howard Zucker of Columbia University, proposes that we take stem cells from embryos at the same point at which we take organs from children and adults: right after they die. (slate.com)
  • He cites an experiment in which stem cells from arrested frog embryos were injected into normal frog embryos. (slate.com)
  • Twenty-five percent of the cells began to divide again and were absorbed into the new embryos. (slate.com)
  • They're also wary of the Columbia team's suggestion that stem cells could be harvested from embryos "in extremis," i.e., near death. (slate.com)
  • In other words, the parts of an embryo-or the parts that normally would become an embryo-might produce stem cells, even if, to avoid the moral problem, we kept these parts incomplete or severed. (slate.com)
  • Then, once the cell begins to divide, reactivate the gene, too late to organize the embryo but early enough to make stem cells. (slate.com)
  • The addition of the two growth phases into the cell cycle allows for the cells to increase in size, as up to this point the blastomeres undergo reductive divisions in which the overall size of the embryo does not increase, but more cells are created. (wikipedia.org)
  • A germ layer is a group of cells in an embryo that interact with each other as the embryo develops and contribute to the formation of all organs and tissues. (asu.edu)
  • Research is needed to determine the most viable stem cell lines and reliable ways to promote the differentiation of pluripotent stem cells into specific cell types (neurons, muscle cells, etc. (jci.org)
  • The Kit proto-oncogene encodes a tyrosine kinase receptor whose ligand is a paracrine protein called stem cell factor (SCF), which is important in hematopoiesis (formation of cells in blood). (wikipedia.org)
  • Theoretically, tissues generated from cells cloned from a patient's own adult nucleus should not trigger an immune response, but it is possible that subtle differences caused by the foreign cytoplasm in the donor egg might cause a rejection response. (encyclopedia.com)
  • With the somatic, or adult cell nucleus, the egg begins to develop into a blastocyst, essentially a sphere containing a cluster of unspecialized stem cells. (natcath.org)
  • This research focuses on four discrete neuron types in the mouse CNS that are amenable to accurate and economical quantitative analysis: retinal ganglion cells (large projection neurons), photoreceptors, horizontal cells (smaller interneurons), and neurons in the dorsal lateral geniculate nucleus. (nervenet.org)
  • We will study four well-defined and interconnected cell populations in the mouse primary visual system (photoreceptors, horizontal cells, retinal ganglion cells, and neurons in the dorsal lateral geniculate nucleus). (nervenet.org)
  • Development will ensue normally and after many mitotic divisions, this single cell forms a blastocyst (an early stage embryo with about 100 cells) with an identical genome to the original organism (i.e. a clone). (wikipedia.org)
  • The aim of carrying out this procedure is to obtain pluripotent cells from a cloned embryo. (wikipedia.org)
  • Originating from the lateral ganglionic eminence, one of the three embryonic structures that eventually become specific parts of the brain, the sub-ventricular zone (SVZ) is a group of cells that develop along the surface of the ventricular layer of the brain, following the creation of the cortical plate in embryos. (wikipedia.org)
  • mice
  • Hurlbut's first choice is the human equivalent of cdx2, the gene in mice that directs the formation of the placenta. (slate.com)
  • cell
  • An adult cell from the patient is then introduced into the egg and it is artificially stimulated to divide, resulting in a growing embryo which is a clone of the patient. (clmagazine.org)
  • Here the animal egg's nucleus is removed and, once again, an adult human cell from the patient is introduced into the animal egg and development is stimulated. (clmagazine.org)
  • The good news is that we may have figured out how to solve the moral problem that's been holding up stem-cell research. (slate.com)
  • He seems to be the only person in this debate who has figured out that the Catholic fixation on the technical definition of a human embryo, which stem-cell researchers regard as a roadblock, actually presents an opportunity. (slate.com)
  • The plan would be to follow the recipe for cloning-put the nucleus of a body cell into a gutted egg cell-but turn off cdx2. (slate.com)
  • Margaret Adaline Reed Lewis (1881-1970) was an American cell biologist and embryologist who made contributions to cancer research and cell culture techniques, and was likely the first person to successfully grow mammalian tissue in vitro. (wikipedia.org)
  • In 1908, Margaret Reed researched in Berlin in Max Hartmann's lab where she performed probably the first in vitro mammalian cell culture with guinea pig bone marrow by explanting the bone marrow and placing it into a nutrient-rich agar produced by fellow lab researcher Rhoda Erdmann and incubating the sample. (wikipedia.org)
  • Since the Lewises main interest was microscopic cell structures, their objective was to create optically clear media, which led to the creation of the Locke-Lewis solution. (wikipedia.org)
  • As a result, this couple's greatest impact on embryology and cell biology in the twentieth century was teaching later generations of biologists the basic factors involved in tissue culture based on what they had learned from their research. (wikipedia.org)
  • With so many avenues opened by cell culture to explore, Margaret Lewis and her husband diverged in their area of study, with Margaret Lewis choosing to focus on microbiological problems, which involved close observations of chick embryo intestines reacting to typhoid bacilli in the medium in which it was grown. (wikipedia.org)
  • During the blastula stage of development, a significant amount of activity occurs within the early embryo to establish cell polarity, cell specification, axis formation, and regulate gene expression. (wikipedia.org)
  • The study of the blastula and of cell specification has many implications on the field of stem cell research as well as the continued improvement of fertility treatments. (wikipedia.org)
  • This has led to an intense debate that threatens to limit embryonic stem cell research. (jci.org)
  • A stem cell is defined by two properties (see A stem cell research lexicon ). (jci.org)
  • In the first one, first messenger cross through the cell membrane, binding and activating intracellular receptors localized at nucleus or cytosol, which then act as transcriptional factors regulating directly gene expression. (wikipedia.org)
  • That nucleus is then replaced with the nucleus from a donor s skin, liver, brain or any other cell in the body. (natcath.org)
  • Some Catholic leaders, activists in the pro-life movement, and legislators oppose embryonic stem cell research, while others believe certain forms of the research present morally acceptable means of achieving long-sought medical gains. (natcath.org)
  • The technique consists of taking an enucleated oocyte (egg cell) and implanting a donor nucleus from a somatic (body) cell. (wikipedia.org)
  • It is a technique for cloning in which the nucleus of a somatic cell is transferred to the cytoplasm of an enucleated egg. (wikipedia.org)
  • The nucleus of the donor egg cell is removed and discarded, leaving it 'deprogrammed. (wikipedia.org)
  • After being inserted into the egg, the somatic cell nucleus is reprogrammed by its host egg cell. (wikipedia.org)
  • Somatic cell nuclear transplantation has become a focus of study in stem cell research. (wikipedia.org)
  • Developmental Biology
  • Flat Mount Preparation for Observation and Analysis of Zebrafish Embryo Specimens Stained by Whole Mount In situ Hybridization Christina N. Cheng 1 , Yue Li 1 , Amanda N. Marra 1 , Valerie Verdun 1 , Rebecca A. Wingert 1 1 Department of Biological Sciences, University of Notre Dame The zebrafish embryo is an excellent model for developmental biology research. (jove.com)
  • tissues
  • Most plants, in particular, can safely reach temperatures of −4 °C to −12 °C. Certain bacteria, notably Pseudomonas syringae, produce specialized proteins that serve as potent ice nucleators, which they use to force ice formation on the surface of various fruits and plants at about −2 °C. The freezing causes injuries in the epithelia and makes the nutrients in the underlying plant tissues available to the bacteria. (wikipedia.org)
  • characteristics
  • There are several important characteristics that indicate protein formation from amino acids requires information. (icr.org)
  • A few days after doing so, she found that some of the nuclei exhibited characteristics of mitosis. (wikipedia.org)
  • biomedical
  • Can you identify the objects in these biomedical research images? (pewtrusts.org)
  • Pew's biomedical scholars and fellows are on the cutting edge of biomedical research-using new tools and techniques to tackle complex questions about human health. (pewtrusts.org)
  • species
  • These well-characterized ESC lines not only will enrich our understanding of pluripotency programs in the ungulate species but also will provide a useful resource for the creation of transgenic ungulate models of human diseases. (pnas.org)
  • Scheme
  • Hurlbut, an earnest young member of the council's conservative wing, has been working for two years on a scheme to end-run the problem of killing embryos. (slate.com)
  • development
  • Read more about his research into this phenomenon, also known as "handedness," which plays an important role in embryonic development as well as in genetic diseases and birth defects. (pewtrusts.org)
  • Recording and contextualizing the science of embryos, development, and reproduction. (asu.edu)
  • These Aims were designed to allow the testing of our hypotheses that control over the MSC microenvironment, and inclusion of signals present during normal development that are both permissive and instructive for cartilage formation and maturation, will lead to the generation of constructs with properties akin to native tissue and improved repair. (upenn.edu)
  • The history of Earth concerns the development of planet Earth from its formation to the present day. (wikipedia.org)
  • human
  • Should blastocysts be protected under the same laws that govern research on human subjects? (jci.org)
  • If successful, his campaign would essentially shut down any human genetic bioscience research efforts in Missouri. (natcath.org)
  • If his view prevails, one of the most ambitious research efforts in the Midwest may be forced to move elsewhere, and university work on human genetics could be in jeopardy. (natcath.org)
  • enough
  • If a hypothetical nucleus is too small, the energy that would be released by forming its volume is not enough to create its surface, and nucleation does not proceed. (wikipedia.org)
  • Freezing does not start until the temperature is low enough to provide enough energy to form stable nuclei. (wikipedia.org)
  • method
  • The problem with this method is that even after removal of the animal nucleus, there still remains animal DNA within the animal egg, inside tiny energy-making components called mitochondria. (clmagazine.org)
  • Science
  • This is partly due to its total absence from secondary school science curricula and partly because it has remained in the domain of research biologists. (creation.com)
  • This paper, authored by John D. Gearhart and his research team - Michael J Shamblott, Joyce Axelman, Shunping Wang, Elizabeith M. Bugg, John W. Littlefield, Peter J. Donovan, Paul D. Blumenthal, and George R. Huggins - was published in Proceedings of the National Academy of Science soon after James A. (asu.edu)
  • scientists
  • The above quote from Ian Wilmut, the man who captured the world's attention with his creation of Dolly, the cloned sheep, should awaken us all to the vast power of the scientific community, as well as to the desire for total control held by so many scientists in this post-modern era. (cbhd.org)
  • Instead of calling this cloned organism an embryo, which is precisely what it is, scientists have labeled it an "activated egg. (cbhd.org)
  • parts
  • God appears to have left His unmistakable signature throughout His creation, even on the smallest parts. (icr.org)
  • The distinction Hurlbut wants to draw and exploit is between a whole embryo and its parts. (slate.com)
  • animal
  • Julia Barlow Platt studied neural crests in animal embryos and became involved in politics in the US during the nineteenth and twentieth centuries. (asu.edu)
  • work
  • Mendel's work went largely unnoticed after its first publication in 1866, but was rediscovered in the late 19th century by Hugo de Vries, Carl Correns, and Erich von Tschermak, who (claimed to have) reached similar conclusions in their own research. (wikipedia.org)
  • shown
  • Our progress during the ongoing grant has shown a role for matrix and cellular density, the timing of material degradation, introduction of soluble inductive factors, and mechanical loading (both compression and sliding contact) in guiding cartilage formation and maturation. (upenn.edu)
  • Vestibular nuclei have been shown to span all the rhombomeres, some correlating with the boundaries of the rhombomeres. (wikipedia.org)