Endometrium(en-do-MEE-tree-um) The layer of tissue that lines the uterus.
Endothelialrelating to a flat layer of cells lining the heart, for example, or blood vessels.
EngraftmentThe process in which transplanted stem cells or bone marrow cells migrate to the bone marrow and begin producing healthy red blood cells, white blood…
EpiblastGives rise to the ectoderm and mesoderm. The mesoderm then displaces the hypoblast cells and forms the entodermal cell layer on its inner surface.
Epidermal growth factor (EGF)A cell messenger protein that has effects including stimulation of epidermal development, in newborn animals it hastens eyelid-opening and tooth-eruption
Epithelium(EP-ih-THEE-lee-um) A thin layer of tissue that covers organs, glands, and other structures within the body.
Erythrocyte(eh-RITH-roh-site) A cell that carries oxygen to all parts of the body. Also called RBC and red blood cell.
Ex vivo(ex VEE-voh) Outside of the living body. Refers to a medical procedure in which an organ, cells, or tissue are taken from a living body for a treatment or…
Extracellular matrixThe microenvironment next to a cell that allows for structural support, orientation, and connections for cell-to-cell interactions and formation of…
Extraembryonic tissuesIntrauterine tissues that support the embryo's placenta, umbilical cord, and amniotic sac.
Feeder cell layerCells that are utilized in co-culture to maintain pluripotent stem cells. Cells usually consist of mouse embryonic fibroblasts.
Feeder layerCells used in co-culture to maintain pluripotent stem cells. Cells usually consist of mouse embryonic fibroblasts.
FertilizationThe union of two gametes from opposite sexes to form a zygote. Typically, each gamete contains a haploid set of chromosomes.
Fetal calf serumA type of culture medium often used in the culture of stem cells. It provides a number of growth factors.
Fetus(FEET-us) The developing offspring from 7 to 8 weeks after conception until birth.
FibroblastA connective tissue cell that makes and secretes collagen proteins.
Fluorescence-activated cell sorting (FACS)A technique that can separate and analyze cells, which are labeled with fluorochrome-conjugated antibody, by their fluorescence and light scattering…
FollistatinAn inhibitory factor produced during embryonic development that affects the growth and differentiation of the pancreas.
GameteA haploid sex cell, egg or sperm, that contains a single copy of each chromosome.
Gamma-interferonA type of small protein with antiviral activity, made by T lymphocytes.
Gap junctionsCommunicating cell-cell junctions that allow ions and small molecules to pass from the cytoplasm of one cell to the cytoplasm of another cell.
GastrulaAn early animal embryo consisting of two layers of cells; an embryological stage following the blastula.
GastrulationThe process whereby the cells of the blastocyst are translocated to establish three germ layers.
GeneThe functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a…
Genital RidgeFormation of a genital ridge requires at least two genes, WT-1, which is also important in early kidney formation, and SF-1, required for the development…
GenomeThe complete genetic material of an organism.
Genomic imprintingA biochemical phenomenon that determines, for certain specific genes, which one of the pair of identical genes, the mother's or the father's, will be…
Germ layersThe three germ layers are the endoderm, mesoderm and ectoderm and are the three precursory tissue layers of the early, primitive embryo (which form at…
GestationThe period between conception (fertilization of the egg ) to parturition (birth) spent in utero by the foetus of viviparous animals.
GliaThe nonneuronal or supporting tissue (neuroglia) of the brain and spinal cord.
Glial cells(glee'-ul sells) branched cells that make up the supporting structure of the nervous (brain & spinal cord) tissue.
GlucagonA hormone produced by the pancreas that increases the level of glucose (sugar) in the blood.
glycoproteinA protein that has sugar molecules attached to it.
gonadThe part of the reproductive system that produces and releases eggs (ovary) or sperm (testicle/testis).
Gonadal ridgeAnatomic site in the early fetus where primordial germ cells (PGCs) are formed.
Gonadal ridgesEmbryonic structures arising in humans at about five weeks, eventually developing into gonads (either testes or ovaries).
GonadsThe embryonic sex gland before it becomes a definitive testis or ovary.
GoosecoidGene that encodes a transcription factor that is important for determining craniofacial orientation and features in the vertebrate embryo.
Graft Versus Host Disease (GVHD)A side effect of a bone marrow or stem cell transplant that occurs when new bone marrow or stem cells (the graft) reject or attack the patient's body (the…
Granulocyte(GRAN-yoo-loh-SITE) A type of white blood cell that fights bacterial infection. Neutrophils, eosinophils, and basophils are granulocytes.
Granulose cellsCells surrounding and maintaining the ovarian follicle.
Green Fluorescent Protein(Abbreviation: GFP). A protein derived from a species of jelly fish, that fluoresces when exposed to ultra violet light.
Growth FactorsSubstances sometimes given to transplant patients to stimulate the production of blood cells, or to stem cell donors to mobilize stem cells into the…
Hanging drop methodA technique used to culture embryonic stem cells so that they develop into embryoid bodies.
HaploidA cell or organism containing one of each of the pairs of homologous chromosomes found in the normal diploid cell.
Haploid human cellA cell such as an egg or sperm that contains only twenty-three chromosomes.
Hematological OncologistA medical doctor who specializes in diagnosing and treating malignancies, or cancers, of the blood and blood- forming tissues.
Hematologist(HEE-muh-TAH-loh-jist) A doctor who specializes in treating blood disorders.
Hematopoiesis(hee-MA-toh-poy-EE-sus) The formation of new blood cells.
Hematopoietic cell transplantationThe transplantation of hematopoietic stem cells with blood-forming potential. Hematopoietic stem cells provide rapid and sustained reconstitution of blood…
Hematopoietic stem cellAn unspecialized precursor cell that will develop into a mature blood cell. See also cell
Hematopoietic stem cellsThe precursors of mature blood cells that are defined by their ability to replace the bone marrow system following its obliteration (for example, by…
HistocompatibleA tissue or organ from a donor (the person giving the organ or tissue) that will not be rejected by the recipient (the patient in whom the tissue or organ…
Hoechst dyeA dye used to identify hematopoietic stem cells (HSCs).
Homologous1. General definition: from the same source, or having the same evolutionary function or structure. 2.
Homologous recombinationThe exchange of DNA fragments between two DNA molecules or chromatids of paired chromosomes (during crossing over) at the site of identical nucleotide…
Hox genesConsists of at least 38 encoded nucleotides that contain genes found in four clusters on four different chromosomes.
HSC markersCell-surface molecules that are used to identify hematopoietic stem cells.
Human embryonic stem cellA stem cell that is derived from the inner cell mass of a blastocyst and can differentiate into several tissue types in a dish.
Human Leukocyte Antigen (HLA)A distinguishing series of proteins that exist on the surface of every white blood cell to help the cells discriminate between "friendly" cells and…
Hurler syndromeA heritable condition involving deficiency of an enzyme (alpha-L-iduronidase), leading to abnormal accumulations of materials inside cells, then resulting…
HybridomaA hybrid cell, composed of a B Iymphocyte fused to a tumor cell, which grows indefinitely in tissue culture and is selected for the secretion of a…
HydroxyapatiteA natural mineral structure that contains calcium and phosphate ions that provide the power for the formation of bones and teeth.
HypoblastThe inner cell layer, or endoderm, which develops during the formation of the embryonic germ layers.
ICM cellsCells from the inner cell mass, a population of cells inside the blastula that give rise to the body of the new organism rather than to the chorion or…
Identical twinningProcess in which genetically identical organisms arise from symmetrical division and separation of totipotent cells.
immune system(ih-MYOON SIS-tem) The complex group of organs and cells that defends the body against infections and other diseases.
Immune system cellsWhite blood cells or leukocytes that originate from the bone marrow. They include antigen presenting cells, such as dendritic cells, T and B lymphocytes…
Immune-function assayA general term for a number of tests based on an immune cell's ability to carry out a particular immune function.
Immunocompromised miceThese genetically altered mice are used for transplantation experiments because they usually do not reject the transplanted tissue.
ImmunodeficientUnable to develop a normal immune response to, for example, a foreign substance.
ImmunofluorescenceThe detection of antibodies by using special proteins labeled with fluorescein.
ImmunogenicRelating to or producing an immune response.
ImmunohistologyExamination of tissues through specific immunostaining techniques.
Immunophenotyping(IM-yoo-no-FEE-no-tie-ping) A process used to identify cells, based on the types of antigens or markers on the surface of the cell.
Immunosuppressive drugsDrugs that prevent or interfere with the development of an immunologic response.
ImplantationThe attachement of the blastocyst to the uterine lining, and its subsequent embedding there. (Based on SMD)
In vitro(in VEE-troh) In the laboratory (outside the body). The opposite of in vivo (in the body).
In vitro fertilization(in VEE-troh FER-tih-lih-ZAY-shun) A procedure in which eggs are removed from a woman's ovary and combined with sperm outside the body to form embryos.
In vitro fertilization (IVF)The union of an egg and sperm, where the event takes place outside the body and in an artificial environment (the literal meaning of "in vitro" is "in…
In vivoIn the body. The opposite of in vitro (outside the body or in the laboratory).
Indomethacin(IN-doh-MEH-thuh-sin) A drug that reduces pain, fever, swelling, and redness. It is also being used to reduce tumor-induced suppression of the immune…
Induced pluripotent stem cellsAdult cells reprogrammed to an embryonic stem cell–like state by being forced to express factors important for maintaining the "stemness" of embryonic…