prophase

(redirected from Chromatin condensation)
Also found in: Dictionary, Thesaurus, Encyclopedia.
Related to Chromatin condensation: prophase

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 ?
Effects of ethanol consumption on chromatin condensation and DNA integrity of epididymal spermatozoa in rat.
ROT induces [O.sub.2.sup.*-]/[H.sub.2][O.sub.2] generation, mitochondrial depolarization, NF-[kappa]B, p53, and c-Jun transcription factor activation, AIF nuclear translocation, caspase-3 activation, chromatin condensation (stage I) and nuclei fragmentation (stage II), DJ-1 cytoplasmic aggregates, and upregulation of Parkin, typical characteristics of apoptosis in Jurkat cells cultured in G11 milieu.
* Apoptosis-like PCD--Stage I chromatin condensation--less compact chromatin condensation.
Some of the changes observed include cytoplasm condensation with a pronounced decrease in cell volume, chromatin condensation and fragmentation, plasma membrane blebbing and degeneration of the nucleus into formation of apoptotic bodies (Figures 5(b), 5(c), and 5(d)).
Chromatin condensation is not associated with apoptosis.
Influence of incubation on the chromatin condensation and nuclear stability of human spermatozoa by flow cytometry.
Enzo Biochem, Inc.'s Life Sciences division has added a new apoptosis detection kit for monitoring chromatin condensation to its CELLestial product line for live cell analysis.
The increased sensitivity to DNA damage in abnormal spermatozoa is probably due to failed chromatin condensation, which makes DNA more accessible to damage.
However, sperms of fish caught from the polluted sites showed variable deformations including: changes in head morphology, incomplete chromatin condensation, malformed middle piece, altered axonemal structure, wavy and sometimes ruptured plasma membrane, head-to-head and head-to-tail sperm agglutinations.
Colleters of the outermost stipule show some cells with cytoplasm darkening, nuclear chromatin condensation, large vacuoles resulting from vacuole fusion, and a reduction in the number of organelles (Fig.