Metaphase

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Metaphase

Metaphase, from the ancient Greek

Ancient Greek

Ancient Greek is the historical stage in the development of the Greek language spanning across the Archaic Greece , Classical Greece , and Hellenistic civilization periods of ancient Greece and the classical antiquity....
µet? (after) and f?s?? (stage), is a stage of mitosis

Mitosis

Mitosis is the process in which a eukaryotic cell separates the chromosomes in its cell nucleus, into two identical sets in two daughter nuclei....
in the eukaryotic

Eukaryote

Animals, plants, fungus, and protists are eukaryotes , organisms whose Cell are organized into complex structures enclosed within Cell membrane....
cell cycle

Cell cycle

The cell cycle, or cell-division cycle, is the series of events that take place in a cell leading to its division and duplication . In cells without a nucleus , the cell cycle occurs via a process termed binary fission....
in which condensed chromosome

Chromosome

A chromosome is an organized structure of DNA and protein that is found in Cell . A chromosome is a single piece of DNA that contains many genes, regulatory sequence and other genetic sequence....
s, carrying genetic information

DNA sequence

A DNA sequence or genetic sequence is a succession of letters representing the primary structure of a real or hypothetical DNA molecule or strand, with the capacity to carry information as described by the central dogma of molecular biology....
, align in the middle of the cell

Cell (biology)

The cell is the structural and functional unit of all known Life organisms. It is the smallest unit of an organism that is classified as living, and is often called the building bricks of life....
before being separated into each of the two daughter cells.

Preceded by events in prometaphase

Prometaphase

Prometaphase is the phase of mitosis following prophase and preceding metaphase, in eukaryote somatic Cell s.The nuclear envelope breaks into fragments and disappears....
and followed by anaphase

Anaphase

Anaphase, is from the ancient Greek ??? and f?s?? , is the stage of mitosis when chromosomes separate in a eukaryote cell . Each chromatid moves to opposite poles of the cell, the opposite ends of the mitotic spindle, near the microtubule organizing centers....
, microtubule

Microtubule

Microtubules are one of the components of the cytoskeleton. They have a diameter of 25 Nanometre and length varying from 200 nanometers to 25 micrometers....
s formed in prophase

Prophase

Prophase is a stage of mitosis in which the chromatin condenses into a highly ordered structure called a chromosome in which the chromatin becomes visible....
have already found and attached themselves to kinetochore

Kinetochore

The kinetochore is the protein structure on chromosomes where the spindle fibers attach during division to pull the chromosomes apart.The kinetochore forms in eukaryotes and assembles on the centromere and links the chromosome to microtubule polymers from the mitotic spindle during mitosis and meiosis....
s in metaphase.

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Encyclopedia

Metaphase, from the ancient Greek

Ancient Greek

Mitosis

Mitosis is the process in which a eukaryotic cell separates the chromosomes in its cell nucleus, into two identical sets in two daughter nuclei....
in the eukaryotic

Eukaryote

Animals, plants, fungus, and protists are eukaryotes , organisms whose Cell are organized into complex structures enclosed within Cell membrane....
cell cycle

Cell cycle

Chromosome

DNA sequence

Cell (biology)

Preceded by events in prometaphase

Prometaphase

Prometaphase is the phase of mitosis following prophase and preceding metaphase, in eukaryote somatic Cell s.The nuclear envelope breaks into fragments and disappears....
and followed by anaphase

Anaphase

Microtubule

Microtubules are one of the components of the cytoskeleton. They have a diameter of 25 Nanometre and length varying from 200 nanometers to 25 micrometers....
s formed in prophase

Prophase

Kinetochore

Centromere

A centromere is a region of DNA typically found near the middle of a chromosome where two sister chromatids come in contact. It is involved in cell division as the point of mitotic spindle....
s of the chromosomes convene themselves on the metaphase plate, an imaginary line that is equidistant from the two centrosome

Centrosome

In cell biology, the centrosome is an organelle that serves as the main microtubule organizing center of the animal cell as well as a regulator of cell-cycle progression....
poles. This even alignment is due to the counterbalance of the pulling powers generated by the opposing kinetochores, analogous to a tug of war between equally strong people. In certain types of cells, chromosomes do not line up at the metaphase plate and instead move back and forth between the poles randomly, only roughly lining up along the middleline. Early events of metaphase can coincide with the later events of prometaphase, as chromosomes with connected kinetochores will start the events of metaphase individually before other chromosomes with unconnected kinetochores that are still lingering in the events of prometaphase.

One of the cell cycle checkpoint

Cell cycle checkpoint

Cell cycle checkpoints are control mechanisms that ensure the fidelity of cell division in eukaryotic cell . These checkpoints verify whether the processes at each phase of the cell cycle have been accurately completed before progression into the next phase....
s occurs during prometaphase and metaphase. Only after all chromosomes have become aligned at the metaphase plate, when every kinetochore is properly attached to a bundle of microtubules, does the cell enter anaphase. It is thought that unattached or improperly attached kinetochores generate a signal to prevent premature progression to anaphase, even if most of the kinetochores have been attached and most of the chromosomes have been aligned. Such a signal creates the mitotic spindle checkpoint

Spindle checkpoint

The spindle checkpoint blocks the entry of a cell undergoing mitosis into Mitosis#Anaphase until all Chromosome are properly attached to the meiotic or mitotic spindle....
. This would be accomplished by regulation of the Anaphase Promoting Complex, securin

Securin

Securin is a protein involved in anaphase triggering. It has two identified roles; the first one is to help the transport of separase to the Cell nucleus and the second role is to inhibit the catalytic activity of separase....
, and separase

Separase

Separase is a cysteine protease responsible for triggering anaphase by hydrolysing cohesin which is the protein responsible for binding sister chromatids during metaphase....
.

Metaphase in the study of cancer and genetics

The analysis of metaphase chromosome

Chromosome

Cancer

Cancer is a class of diseases in which a group of cell display uncontrolled growth , invasion , and sometimes metastasis . These three malignant properties of cancers differentiate them from benign tumors, which are self-limited, do not invade or metastasize....
cytogenetics

Cytogenetics

Cytogenetics is a branch of genetics that is concerned with the study of the structure and function of the cell, especially the chromosomes. It includes routine analysis of G banding chromosomes, other cytogenetic banding techniques, as well as molecular cytogenetics such as fluorescent in situ hybridization and comparative genomic hybridiz...
. Malignant cells from solid tumor

Tumor

A tumor or tumour is the name for a swelling or lesion formed by an abnormal growth of cells . Tumor is not synonymous with cancer. A tumor can be Benign neoplasm, Carcinoma in situ or malignant, whereas cancer is by definition malignant....
s or leukemia

Leukemia

Leukemia is a cancer of the blood or bone marrow and is characterized by an abnormal proliferation of blood Cell , usually white blood cells ....
samples are grown in short term culture and dropped onto microscope

Microscope

A microscope is an Laboratory equipment for viewing objects that are too small to be seen by the naked or unaided eye. The science of investigating small objects using such an instrument is called microscopy....
slides to generate metaphase preparations. Staining of the slides, often with Giemsa or Quinacrine

Quinacrine

Quinacrine is a medication with a number of different medicine applications....
, produces a pattern of in total up to several hundred bands. Inspection of the stained metaphases allows the determination of numerical and structural changes in the tumor cell genome, for example, losses of chromosomal segments or translocations

Chromosomal translocation

In genetics, a chromosome translocation is a chromosome abnormality caused by rearrangement of parts between nonhomologous chromosomes. A fusion gene may be created when the translocation joins two otherwise separated genes, an event which is common in cancer....
, which may lead to chimeric oncogene

Oncogene

An oncogene is a gene that, when mutated or expressed at high levels, helps turn a normal cell into a cancer cell.Many cells normally undergo a programmed form of death ....
s, such as bcr-abl in Chronic myelogenous leukemia

Chronic myelogenous leukemia

Chronic myelogenous leukemia , also known as chronic granulocytic leukemia , is a form of leukemia characterized by the increased and unregulated growth of predominantly myeloid cells in the bone marrow and the accumulation of these cells in the blood....
.

Additionally, normal metaphase spreads are used as hybridization matrix for comparative genomic hybridization

Comparative genomic hybridization

Comparative genomic hybridization or Chromosomal Microarray Analysis is a molecular-cytogenetic method for the analysis of copy number changes in the DNA content of a given subject's DNA and often in tumor cell ....
(CGH) experiments.