molecular function |
| GO:0005524 | | ATP binding | | Interacting selectively and non-covalently with ATP, adenosine 5'-triphosphate, a universally important coenzyme and enzyme regulator. |
| GO:0003677 | | DNA binding | | Any molecular function by which a gene product interacts selectively and non-covalently with DNA (deoxyribonucleic acid). |
| GO:0004707 | | MAP kinase activity | | Catalysis of the reaction: protein + ATP = protein phosphate + ADP. This reaction is the phosphorylation of proteins. Mitogen-activated protein kinase; a family of protein kinases that perform a crucial step in relaying signals from the plasma membrane to the nucleus. They are activated by a wide range of proliferation- or differentiation-inducing signals; activation is strong with agonists such as polypeptide growth factors and tumor-promoting phorbol esters, but weak (in most cell backgrounds) by stress stimuli. |
| GO:0008353 | | RNA polymerase II carboxy-terminal domain kinase activity | | Catalysis of the reaction: ATP + (DNA-directed RNA polymerase II) = ADP + phospho-(DNA-directed RNA polymerase II); phosphorylation occurs on residues in the carboxy-terminal domain (CTD) repeats. |
| GO:0042802 | | identical protein binding | | Interacting selectively and non-covalently with an identical protein or proteins. |
| GO:0016301 | | kinase activity | | Catalysis of the transfer of a phosphate group, usually from ATP, to a substrate molecule. |
| GO:0031435 | | mitogen-activated protein kinase kinase kinase binding | | Interacting selectively and non-covalently with a mitogen-activated protein kinase kinase kinase, any protein that can phosphorylate a MAP kinase kinase. |
| GO:0000166 | | nucleotide binding | | Interacting selectively and non-covalently with a nucleotide, any compound consisting of a nucleoside that is esterified with (ortho)phosphate or an oligophosphate at any hydroxyl group on the ribose or deoxyribose. |
| GO:0019902 | | phosphatase binding | | Interacting selectively and non-covalently with any phosphatase. |
| GO:0001784 | | phosphotyrosine residue binding | | Interacting selectively and non-covalently with a phosphorylated tyrosine residue within a protein. |
| GO:0005515 | | protein binding | | Interacting selectively and non-covalently with any protein or protein complex (a complex of two or more proteins that may include other nonprotein molecules). |
| GO:0004672 | | protein kinase activity | | Catalysis of the phosphorylation of an amino acid residue in a protein, usually according to the reaction: a protein + ATP = a phosphoprotein + ADP. |
| GO:0019901 | | protein kinase binding | | Interacting selectively and non-covalently with a protein kinase, any enzyme that catalyzes the transfer of a phosphate group, usually from ATP, to a protein substrate. |
| GO:0004674 | | protein serine/threonine kinase activity | | Catalysis of the reactions: ATP + protein serine = ADP + protein serine phosphate, and ATP + protein threonine = ADP + protein threonine phosphate. |
| GO:0008134 | | transcription factor binding | | Interacting selectively and non-covalently with a transcription factor, any protein required to initiate or regulate transcription. |
| GO:0016740 | | transferase activity | | Catalysis of the transfer of a group, e.g. a methyl group, glycosyl group, acyl group, phosphorus-containing, or other groups, from one compound (generally regarded as the donor) to another compound (generally regarded as the acceptor). Transferase is the systematic name for any enzyme of EC class 2. |
biological process |
| GO:0050853 | | B cell receptor signaling pathway | | A series of molecular signals initiated by the cross-linking of an antigen receptor on a B cell. |
| GO:0060020 | | Bergmann glial cell differentiation | | The process in which neuroepithelial cells of the neural tube give rise to Brgmann glial cells, specialized bipotential progenitors cells of the cerebellum. Differentiation includes the processes involved in commitment of a cell to a specific fate. |
| GO:0038127 | | ERBB signaling pathway | | A series of molecular signals initiated by binding of a ligand to a member of the ERBB family of receptor tyrosine kinases on the surface of a cell, and ending with regulation of a downstream cellular process, e.g. transcription. |
| GO:0070371 | | ERK1 and ERK2 cascade | | An intracellular protein kinase cascade containing at least ERK1 or ERK2 (MAPKs), a MEK (a MAPKK) and a MAP3K. The cascade can also contain two additional tiers: the upstream MAP4K and the downstream MAP Kinase-activated kinase (MAPKAPK). The kinases in each tier phosphorylate and activate the kinases in the downstream tier to transmit a signal within a cell. |
| GO:0038095 | | Fc-epsilon receptor signaling pathway | | A series of molecular signals initiated by the binding of the Fc portion of immunoglobulin E (IgE) to an Fc-epsilon receptor on the surface of a signal-receiving cell, and ending with regulation of a downstream cellular process, e.g. transcription. The Fc portion of an immunoglobulin is its C-terminal constant region. |
| GO:0038096 | | Fc-gamma receptor signaling pathway involved in phagocytosis | | An Fc-gamma receptor signaling pathway that contributes to the endocytic engulfment of external particulate material by phagocytes. |
| GO:0060397 | | JAK-STAT cascade involved in growth hormone signaling pathway | | The process in which STAT proteins (Signal Transducers and Activators of Transcription) are activated by members of the JAK (janus activated kinase) family of tyrosine kinases, following the binding of physiological ligands to the growth hormone receptor. Once activated, STATs dimerize and translocate to the nucleus and modulate the expression of target genes. |
| GO:0000165 | | MAPK cascade | | An intracellular protein kinase cascade containing at least a MAPK, a MAPKK and a MAP3K. The cascade can also contain two additional tiers: the upstream MAP4K and the downstream MAP Kinase-activated kinase (MAPKAPK). The kinases in each tier phosphorylate and activate the kinases in the downstream tier to transmit a signal within a cell. |
| GO:0000189 | | MAPK import into nucleus | | The directed movement of a MAP kinase to the nucleus upon activation. |
| GO:0050852 | | T cell receptor signaling pathway | | A series of molecular signals initiated by the cross-linking of an antigen receptor on a T cell. |
| GO:0000187 | | activation of MAPK activity | | The initiation of the activity of the inactive enzyme MAP kinase (MAPK). |
| GO:0009887 | | animal organ morphogenesis | | Morphogenesis of an animal organ. An organ is defined as a tissue or set of tissues that work together to perform a specific function or functions. Morphogenesis is the process in which anatomical structures are generated and organized. Organs are commonly observed as visibly distinct structures, but may also exist as loosely associated clusters of cells that work together to perform a specific function or functions. |
| GO:0006915 | | apoptotic process | | A programmed cell death process which begins when a cell receives an internal (e.g. DNA damage) or external signal (e.g. an extracellular death ligand), and proceeds through a series of biochemical events (signaling pathway phase) which trigger an execution phase. The execution phase is the last step of an apoptotic process, and is typically characterized by rounding-up of the cell, retraction of pseudopodes, reduction of cellular volume (pyknosis), chromatin condensation, nuclear fragmentation (karyorrhexis), plasma membrane blebbing and fragmentation of the cell into apoptotic bodies. When the execution phase is completed, the cell has died. |
| GO:0007411 | | axon guidance | | The chemotaxis process that directs the migration of an axon growth cone to a specific target site in response to a combination of attractive and repulsive cues. |
| GO:0061308 | | cardiac neural crest cell development involved in heart development | | The process aimed at the progression of a cardiac neural crest cell over time, from initial commitment of the cell to its specific fate, to the fully functional differentiated cell that contributes to the development of the heart. |
| GO:0072584 | | caveolin-mediated endocytosis | | An endocytosis process that begins when material is taken up into plasma membrane caveolae, which then pinch off to form endocytic caveolar carriers. |
| GO:0007049 | | cell cycle | | The progression of biochemical and morphological phases and events that occur in a cell during successive cell replication or nuclear replication events. Canonically, the cell cycle comprises the replication and segregation of genetic material followed by the division of the cell, but in endocycles or syncytial cells nuclear replication or nuclear division may not be followed by cell division. |
| GO:0006974 | | cellular response to DNA damage stimulus | | Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a stimulus indicating damage to its DNA from environmental insults or errors during metabolism. |
| GO:0097011 | | cellular response to granulocyte macrophage colony-stimulating factor stimulus | | Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a granulocyte macrophage colony-stimulating factor stimulus. |
| GO:0071310 | | cellular response to organic substance | | Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of an organic substance stimulus. |
| GO:0007268 | | chemical synaptic transmission | | The vesicular release of classical neurotransmitter molecules from a presynapse, across a chemical synapse, the subsequent activation of neurotransmitter receptors at the postsynapse of a target cell (neuron, muscle, or secretory cell) and the effects of this activation on the postsynaptic membrane potential and ionic composition of the postsynaptic cytosol. This process encompasses both spontaneous and evoked release of neurotransmitter and all parts of synaptic vesicle exocytosis. Evoked transmission starts with the arrival of an action potential at the presynapse. |
| GO:0006935 | | chemotaxis | | The directed movement of a motile cell or organism, or the directed growth of a cell guided by a specific chemical concentration gradient. Movement may be towards a higher concentration (positive chemotaxis) or towards a lower concentration (negative chemotaxis). |
| GO:0019858 | | cytosine metabolic process | | The chemical reactions and pathways involving cytosine, 4-amino-2-hydroxypyrimidine, a pyrimidine derivative that is one of the five main bases found in nucleic acids; it occurs widely in cytidine derivatives. |
| GO:0060324 | | face development | | The biological process whose specific outcome is the progression of a face from an initial condition to its mature state. The face is the ventral division of the head. |
| GO:0008543 | | fibroblast growth factor receptor signaling pathway | | The series of molecular signals generated as a consequence of a fibroblast growth factor receptor binding to one of its physiological ligands. |
| GO:0007507 | | heart development | | The process whose specific outcome is the progression of the heart over time, from its formation to the mature structure. The heart is a hollow, muscular organ, which, by contracting rhythmically, keeps up the circulation of the blood. |
| GO:0035556 | | intracellular signal transduction | | The process in which a signal is passed on to downstream components within the cell, which become activated themselves to further propagate the signal and finally trigger a change in the function or state of the cell. |
| GO:0060716 | | labyrinthine layer blood vessel development | | The process whose specific outcome is the progression of a blood vessel of the labyrinthine layer of the placenta over time, from its formation to the mature structure. The embryonic vessels grow through the layer to come in close contact with the maternal blood supply. |
| GO:0031663 | | lipopolysaccharide-mediated signaling pathway | | A series of molecular signals initiated by the binding of a lipopolysaccharide (LPS) to a receptor on the surface of a target cell, and ending with regulation of a downstream cellular process, e.g. transcription. Lipopolysaccharides are major components of the outer membrane of Gram-negative bacteria, making them prime targets for recognition by the immune system. |
| GO:0060291 | | long-term synaptic potentiation | | A process that modulates synaptic plasticity such that synapses are changed resulting in the increase in the rate, or frequency of synaptic transmission at the synapse. |
| GO:0060425 | | lung morphogenesis | | The process in which the anatomical structures of the lung are generated and organized. |
| GO:0033598 | | mammary gland epithelial cell proliferation | | The multiplication or reproduction of mammary gland epithelial cells, resulting in the expansion of a cell population. Mammary gland epithelial cells make up the covering of surfaces of the mammary gland. The mammary gland is a large compound sebaceous gland that in female mammals is modified to secrete milk. |
| GO:0045596 | | negative regulation of cell differentiation | | Any process that stops, prevents, or reduces the frequency, rate or extent of cell differentiation. |
| GO:0014032 | | neural crest cell development | | The process aimed at the progression of a neural crest cell over time, from initial commitment of the cell to its specific fate, to the fully functional differentiated cell. |
| GO:0042473 | | outer ear morphogenesis | | The process in which the anatomical structures of the outer ear are generated and organized. The outer ear is the part of the ear external to the tympanum (eardrum). It consists of a tube (the external auditory meatus) that directs sound waves on to the tympanum, and may also include the external pinna, which extends beyond the skull. |
| GO:0018105 | | peptidyl-serine phosphorylation | | The phosphorylation of peptidyl-serine to form peptidyl-O-phospho-L-serine. |
| GO:0018107 | | peptidyl-threonine phosphorylation | | The phosphorylation of peptidyl-threonine to form peptidyl-O-phospho-L-threonine. |
| GO:0016310 | | phosphorylation | | The process of introducing a phosphate group into a molecule, usually with the formation of a phosphoric ester, a phosphoric anhydride or a phosphoric amide. |
| GO:0030168 | | platelet activation | | A series of progressive, overlapping events triggered by exposure of the platelets to subendothelial tissue. These events include shape change, adhesiveness, aggregation, and release reactions. When carried through to completion, these events lead to the formation of a stable hemostatic plug. |
| GO:0030335 | | positive regulation of cell migration | | Any process that activates or increases the frequency, rate or extent of cell migration. |
| GO:0008284 | | positive regulation of cell proliferation | | Any process that activates or increases the rate or extent of cell proliferation. |
| GO:0010800 | | positive regulation of peptidyl-threonine phosphorylation | | Any process that increases the frequency, rate or extent of peptidyl-threonine phosphorylation. Peptidyl-threonine phosphorylation is the phosphorylation of peptidyl-threonine to form peptidyl-O-phospho-L-threonine. |
| GO:0051973 | | positive regulation of telomerase activity | | Any process that activates or increases the frequency, rate or extent of telomerase activity, the catalysis of the reaction: deoxynucleoside triphosphate + DNA(n) = diphosphate + DNA(n+1). |
| GO:1904355 | | positive regulation of telomere capping | | Any process that activates or increases the frequency, rate or extent of telomere capping. |
| GO:0032212 | | positive regulation of telomere maintenance via telomerase | | Any process that activates or increases the frequency, rate or extent of the addition of telomeric repeats by telomerase. |
| GO:0045893 | | positive regulation of transcription, DNA-templated | | Any process that activates or increases the frequency, rate or extent of cellular DNA-templated transcription. |
| GO:0045727 | | positive regulation of translation | | Any process that activates or increases the frequency, rate or extent of the chemical reactions and pathways resulting in the formation of proteins by the translation of mRNA or circRNA. |
| GO:0006468 | | protein phosphorylation | | The process of introducing a phosphate group on to a protein. |
| GO:0090170 | | regulation of Golgi inheritance | | Any process that modulates the rate, frequency or extent of Golgi inheritance. Golgi inheritance is the partitioning of Golgi apparatus between daughter cells at cell division. |
| GO:1900034 | | regulation of cellular response to heat | | Any process that modulates the frequency, rate or extent of cellular response to heat. |
| GO:0051493 | | regulation of cytoskeleton organization | | Any process that modulates the frequency, rate or extent of the formation, arrangement of constituent parts, or disassembly of cytoskeletal structures. |
| GO:2000641 | | regulation of early endosome to late endosome transport | | Any process that modulates the frequency, rate or extent of early endosome to late endosome transport. |
| GO:0014066 | | regulation of phosphatidylinositol 3-kinase signaling | | Any process that modulates the frequency, rate or extent of signal transduction mediated by the phosphatidylinositol 3-kinase cascade. |
| GO:0031647 | | regulation of protein stability | | Any process that affects the structure and integrity of a protein, altering the likelihood of its degradation or aggregation. |
| GO:0051090 | | regulation of sequence-specific DNA binding transcription factor activity | | Any process that modulates the frequency, rate or extent of the activity of a transcription factor, any factor involved in the initiation or regulation of transcription. |
| GO:0032872 | | regulation of stress-activated MAPK cascade | | Any process that modulates the frequency, rate or extent of signal transduction mediated by the stress-activated MAPK cascade. |
| GO:0006355 | | regulation of transcription, DNA-templated | | Any process that modulates the frequency, rate or extent of cellular DNA-templated transcription. |
| GO:0070849 | | response to epidermal growth factor | | Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of an epidermal growth factor stimulus. |
| GO:0043627 | | response to estrogen | | Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of stimulus by an estrogen, C18 steroid hormones that can stimulate the development of female sexual characteristics. |
| GO:0043330 | | response to exogenous dsRNA | | Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of an exogenous double-stranded RNA stimulus. |
| GO:0032496 | | response to lipopolysaccharide | | Any process that results in a change in state or activity of an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a lipopolysaccharide stimulus; lipopolysaccharide is a major component of the cell wall of gram-negative bacteria. |
| GO:0006950 | | response to stress | | Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a disturbance in organismal or cellular homeostasis, usually, but not necessarily, exogenous (e.g. temperature, humidity, ionizing radiation). |
| GO:0009636 | | response to toxic substance | | Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a toxic stimulus. |
| GO:0019233 | | sensory perception of pain | | The series of events required for an organism to receive a painful stimulus, convert it to a molecular signal, and recognize and characterize the signal. Pain is medically defined as the physical sensation of discomfort or distress caused by injury or illness, so can hence be described as a harmful stimulus which signals current (or impending) tissue damage. Pain may come from extremes of temperature, mechanical damage, electricity or from noxious chemical substances. This is a neurological process. |
| GO:0007165 | | signal transduction | | The cellular process in which a signal is conveyed to trigger a change in the activity or state of a cell. Signal transduction begins with reception of a signal (e.g. a ligand binding to a receptor or receptor activation by a stimulus such as light), or for signal transduction in the absence of ligand, signal-withdrawal or the activity of a constitutively active receptor. Signal transduction ends with regulation of a downstream cellular process, e.g. regulation of transcription or regulation of a metabolic process. Signal transduction covers signaling from receptors located on the surface of the cell and signaling via molecules located within the cell. For signaling between cells, signal transduction is restricted to events at and within the receiving cell. |
| GO:0048538 | | thymus development | | The process whose specific outcome is the progression of the thymus over time, from its formation to the mature structure. The thymus is a symmetric bi-lobed organ involved primarily in the differentiation of immature to mature T cells, with unique vascular, nervous, epithelial, and lymphoid cell components. |
| GO:0030878 | | thyroid gland development | | The process whose specific outcome is the progression of the thyroid gland over time, from its formation to the mature structure. The thyroid gland is an endoderm-derived gland that produces thyroid hormone. |
| GO:0060440 | | trachea formation | | The process pertaining to the initial formation of a trachea from unspecified parts. The process begins with the specific processes that contribute to the appearance of the discrete structure and ends when the trachea is recognizable. The trachea is the portion of the airway that attaches to the bronchi as it branches. |
| GO:0006351 | | transcription, DNA-templated | | The cellular synthesis of RNA on a template of DNA. |
| GO:0016032 | | viral process | | A multi-organism process in which a virus is a participant. The other participant is the host. Includes infection of a host cell, replication of the viral genome, and assembly of progeny virus particles. In some cases the viral genetic material may integrate into the host genome and only subsequently, under particular circumstances, 'complete' its life cycle. |
cellular component |
| GO:0005794 | | Golgi apparatus | | A compound membranous cytoplasmic organelle of eukaryotic cells, consisting of flattened, ribosome-free vesicles arranged in a more or less regular stack. The Golgi apparatus differs from the endoplasmic reticulum in often having slightly thicker membranes, appearing in sections as a characteristic shallow semicircle so that the convex side (cis or entry face) abuts the endoplasmic reticulum, secretory vesicles emerging from the concave side (trans or exit face). In vertebrate cells there is usually one such organelle, while in invertebrates and plants, where they are known usually as dictyosomes, there may be several scattered in the cytoplasm. The Golgi apparatus processes proteins produced on the ribosomes of the rough endoplasmic reticulum; such processing includes modification of the core oligosaccharides of glycoproteins, and the sorting and packaging of proteins for transport to a variety of cellular locations. Three different regions of the Golgi are now recognized both in terms of structure and function: cis, in the vicinity of the cis face, trans, in the vicinity of the trans face, and medial, lying between the cis and trans regions. |
| GO:0030424 | | axon | | The long process of a neuron that conducts nerve impulses, usually away from the cell body to the terminals and varicosities, which are sites of storage and release of neurotransmitter. |
| GO:0005901 | | caveola | | A membrane raft that forms small pit, depression, or invagination that communicates with the outside of a cell and extends inward, indenting the cytoplasm and the cell membrane. Examples include flask-shaped invaginations of the plasma membrane in adipocytes associated with caveolin proteins, and minute pits or incuppings of the cell membrane formed during pinocytosis. Caveolae may be pinched off to form free vesicles within the cytoplasm. |
| GO:0005737 | | cytoplasm | | All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures. |
| GO:0005856 | | cytoskeleton | | Any of the various filamentous elements that form the internal framework of cells, and typically remain after treatment of the cells with mild detergent to remove membrane constituents and soluble components of the cytoplasm. The term embraces intermediate filaments, microfilaments, microtubules, the microtrabecular lattice, and other structures characterized by a polymeric filamentous nature and long-range order within the cell. The various elements of the cytoskeleton not only serve in the maintenance of cellular shape but also have roles in other cellular functions, including cellular movement, cell division, endocytosis, and movement of organelles. |
| GO:0005829 | | cytosol | | The part of the cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes. |
| GO:0032839 | | dendrite cytoplasm | | All of the contents of a dendrite, excluding the surrounding plasma membrane. |
| GO:0005769 | | early endosome | | A membrane-bounded organelle that receives incoming material from primary endocytic vesicles that have been generated by clathrin-dependent and clathrin-independent endocytosis; vesicles fuse with the early endosome to deliver cargo for sorting into recycling or degradation pathways. |
| GO:0070062 | | extracellular exosome | | A vesicle that is released into the extracellular region by fusion of the limiting endosomal membrane of a multivesicular body with the plasma membrane. Extracellular exosomes, also simply called exosomes, have a diameter of about 40-100 nm. |
| GO:0005925 | | focal adhesion | | Small region on the surface of a cell that anchors the cell to the extracellular matrix and that forms a point of termination of actin filaments. |
| GO:0005770 | | late endosome | | A prelysosomal endocytic organelle differentiated from early endosomes by lower lumenal pH and different protein composition. Late endosomes are more spherical than early endosomes and are mostly juxtanuclear, being concentrated near the microtubule organizing center. |
| GO:0015630 | | microtubule cytoskeleton | | The part of the cytoskeleton (the internal framework of a cell) composed of microtubules and associated proteins. |
| GO:0005815 | | microtubule organizing center | | An intracellular structure that can catalyze gamma-tubulin-dependent microtubule nucleation and that can anchor microtubules by interacting with their minus ends, plus ends or sides. |
| GO:0005739 | | mitochondrion | | A semiautonomous, self replicating organelle that occurs in varying numbers, shapes, and sizes in the cytoplasm of virtually all eukaryotic cells. It is notably the site of tissue respiration. |
| GO:0072686 | | mitotic spindle | | A spindle that forms as part of mitosis. Mitotic and meiotic spindles contain distinctive complements of proteins associated with microtubules. |
| GO:0005654 | | nucleoplasm | | That part of the nuclear content other than the chromosomes or the nucleolus. |
| GO:0005634 | | nucleus | | A membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. In most cells, the nucleus contains all of the cell's chromosomes except the organellar chromosomes, and is the site of RNA synthesis and processing. In some species, or in specialized cell types, RNA metabolism or DNA replication may be absent. |
| GO:0043204 | | perikaryon | | The portion of the cell soma (neuronal cell body) that excludes the nucleus. |
| GO:0043234 | | protein complex | | A stable macromolecular complex composed (only) of two or more polypeptide subunits along with any covalently attached molecules (such as lipid anchors or oligosaccharide) or non-protein prosthetic groups (such as nucleotides or metal ions). Prosthetic group in this context refers to a tightly bound cofactor. The component polypeptide subunits may be identical. |
| GO:0031143 | | pseudopodium | | A temporary protrusion or retractile process of a cell, associated with flowing movements of the protoplasm, and serving for locomotion and feeding. |
| GO:0005819 | | spindle | | The array of microtubules and associated molecules that forms between opposite poles of a eukaryotic cell during mitosis or meiosis and serves to move the duplicated chromosomes apart. |