prophase


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prophase

 [pro´fāz]
the first stage of cell replication in either meiosis or mitosis.

pro·phase

(prō'fāz),
The first stage of mitosis or meiosis, consisting of linear contraction and increase in thickness of the chromosomes (each composed of two chromatids) accompanied by migration of the two daughter centrioles and their asters toward the poles of the cell. In meiosis, prophase is complex and can be subdivided into stages: preleptotene, leptotene, zygotene, pachytene, diplotene, and diakinesis.
[G. prophasis, from prophainō, to foreshadow]

prophase

(prō′fāz′)
n.
1. The first stage of mitosis, during which the chromosomes condense and become visible, the nuclear membrane breaks down, and the spindle apparatus forms at opposite poles of the cell.
2. The first stage of meiosis, constituted by a series of events that include the thickening and coiling of the chromosomes, synapsis of homologous chromosomes, tetrad formation, and crossing over.

pro·pha′sic (-fā′zĭk) adj.

pro·phase

(prō'fāz)
The first stage of mitosis or meiosis, consisting of linear contraction and increase in thickness of the chromosomes (each composed of two chromatids) accompanied by migration of the two daughter centrioles and their asters toward the poles of the cell.
[G. prophasis, from prophainō, to foreshadow]

prophase

The first stage in cell division by MITOSIS and MEIOSIS, during which CHROMATIN coils up to form chromosomes.

prophase

the first stage of nuclear division (MITOSIS and MEIOSIS) in which the chromosomes coil and thicken and become visible with the optical microscope, condensing onto the inner wall of the NUCLEAR MEMBRANE. As the stage proceeds, the NUCLEOLUS disappears from view and the nuclear membrane disintegrates, leaving a clear area at the edge of the nucleus which contains the CENTROSOME.

Meiosis has a much more complicated prophase than mitosis, and can be summarized thus:

  1. (a) meiosis has two prophases, the first one complex (see below).the second rather similar to prophase in mitosis.
  2. (b) prophase 1 of meiosis can be divided into five substages: LEPTOTENE, ZYGOTENE, PACHYTENE, DIPLOTENE and DIAKINESIS. The essential processes occurring are: (i) pairing of homologous chromosomes, (ii) pairing of nonsister CHROMATIDS forming chiasmata with eventual CROSSING OVER.
References in periodicals archive ?
However, the meiotic behavior of these vectors is different, since during prophase T.
For the hydroalcoholic extract a decrease was observed in the percentage of prophases at the concentration of 1.0%, and a significant increase in metaphases at the concentration of 4.0% (Dunnett, P<0.05) (Table 2).
The acquisition of MedAvante and ProPhase positions WCG in the growing central nervous system and behavioural health assessment markets through the delivery of clinical services and technology solutions that improve signal detection.
Partial arrest appeared at two stages of the first meiotic prophase. A first meiotic arrest probably occurred at the leptotene/zygotene transition, as suggested by the reduced percentage of zygotene nuclei.
HSP70-2 is required for desynapsis of synaptonemal complexes during meiotic prophase in juvenile and adult mouse spermatocytes.
These stages are prophase, prometaphase, metaphase, anaphase, and telophase.
Austin, TX, October 03, 2014 --(PR.com)-- Texas author, Mitchel Street is pleased to announce the release of the first book in his Mitosis fantasy series, "Prophase: A Present Tale."
After germ cell adhesion to an acellular substrate, such growth factors and compounds were able to prevent the occurrence of significant levels of apoptosis in germ cells, stimulate their proliferation and allow most of them to enter into and progress through meiotic prophase I (28), (29).
Prophase Labs Cold-EEZE Cold Remedy Plus Natural Immune Support QuickMelts
Meiosis staggers including prophase I, metaphase I, anaphase I and then telophase I (Fig.
Satajovic reported receiving research grants from Merck and other companies, as well as serving as a consultant to Prophase, Otsuka, Pfizer, Amgen, and United BioSource.