Glossary
Words and phrases commonly used in stem cell research
- ancestor cell
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General term for cell without self-renewal ability that contributes to tissue formation. In some cases it generates tissue stem cells.
Synonyms: precursor cell - asymmetric division
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Cell division resulting in two daughter cells with different properties. Observed in some but not all stem cells and can occur in other types of progenitor cell.
- blastocyst
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An early stage embryo of about 100 cells that has not yet implanted into the womb. The blastocysti is a sphere made up of an outer layer of cells, a fluid-filled cavity and cluster of cells inside called the inner cell mass.
- cancer cell of origin
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Precancerous cell that gives rise to a cancer stem celli. May be a mutated stem cell, or a progenitor cell that has acquired self-renewal capacity through mutation.
- cancer stem cell
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Self-renewing cell responsible for sustaining a cancer and for producing differentiated progeny that form the bulk of the cancer. Cancer stem cells identified in leukaemias and certain solid tumours are critical therapeutic targets.
- cancer-initiating cell
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Cell that can produce a new cancer upon transplantation. A key property of a cancer stem celli.
- cell culture
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The growth of cells in a laboratory dish for experimental research. The cells are grown in a solution, or medium, that contains nutrients and growth factors. Different factors can be added to the culture medium to initiate changes in cell behaviour.
- cell replacement therapy
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Reconstitution of tissue by functional incorporation of transplanted stem-cell progeny. Distinct from 'bystander' trophic, anti-inflammatory or immunomodulatory effects of introduced cells.
- clonal analysis
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Investigation of properties of single cells. Essential for formal demonstration of self-renewal and potencyi.
- commitment
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Engagement in a programme leading to differentiationi. For a stem celli, this means it no longer retains the ability to self-renewi.
- daughter cell
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One of the two or more cells formed in the division of a single cell.
- differentiation
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The process by which cells become specialized to perform particular tasks.
- embryonic stem cell
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Pluripotenti stem-cell lines derived from early embryos before formation of the tissue germ layers.
Synonyms: embryonic stem cells - germ cells
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The reproductive cells in multicellular organisms.
- immortal strand
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The hypothesis of selective retention of parental DNA strands during asymmetric self-renewal. Potential mechanism to protect stem cells from the mutations associated with replication.
- induced pluripotent stem (iPS) cells
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A type of pluripotenti stem celli derived from a non-pluripotent cell, typically an adult somatic celli, by manipulating expression of certain genes.
Synonyms: induced pluripotency, induced pluripotent stem cells, induced pluripotent stem (iPS) cells, iPS cells - lineage
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Term used to describe cells with a common ancestry, that is developing from the same type of identifiable immature cell.
- long-term reconstitution
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Lifelong renewal of tissue by transplanted cells. The definitive test for haematopoietic, epidermal and spermatogonial stem cells.
- multipotent
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Able form multiple mature cell types that constitute an entire tissue or tissues. Example: haematopoietic (blood) stem cells.
- niche
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Cellular micro-environment providing the support and stimuli necessary to sustain self-renewal
- oligopotent
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Able to form two or more mature cell types within a tissue. For example, neural stem cells that can create a subset of neurons in the brain are oligopotenti.
- plasticity
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Unproven notion that tissue stem cells may be able to generate the cell types of another tissue under certain conditions.
- pluripotent
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Able to form all the body's cell lineages, including germ cellsi, and some or even all extraembryonic cell types. Example: embryonic stem cellsi.
- potency
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The range of commitment options available to a cell.
- progenitor cell
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Generic term for any dividing cell with the capacity to give rise to another cell type. Includes possible stem cells in which self-renewal has not yet been demonstrated.
- regenerative medicine
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Reconstruction of diseased or injured tissue by activation of resident cells or by cell transplantation.
- reprogramming
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Increase in potencyi. Occurs naturally in regenerative organisms (dedifferentiation). Induced experimentally in mammalian cells by nuclear transfer, cell fusion, genetic manipulation or in vitro culture.
- self-renewal
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The ability of a stem celli to divide and produce copies of itself for an indefinite period of time. This is the defining property of stem cells.
Synonyms: self-renew - somatic cell
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Any of the cells of a plant or animal other than germ cellsi
Synonyms: somatic cells - stem cell
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A cell that can continuously produce unaltered daughters and also has the ability to produce daughter cells that have different, more restricted properties.
- stemness
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Unproven notion that different stem cells are regulated by common genes and mechanisms.
- tissue stem cell
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Stem celli derived from, or resident in, a fetal or adult tissue, with potencyi limited to cells of that tissue. These cells sustain turnover and repair throughout life in some tissues.
Synonyms: adult stem cell - totipotent
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Sufficient to form entire organism. The zygotei is totipotenti; not demonstrated for any vertebrate stem celli.
- unipotent
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Forms a single mature cell type. For example, spermatogonial stem cells are unipotenti, as they can only form sperm cells.
- zygote
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A single cell resulting from the fusion of male and female gametes (sperm and egg) at fertilization.