pachytene


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pachytene

 [pak´e-tēn]
in prophase of meiosis, the stage following zygotene, during which the chromosomes shorten, thicken, and separate into two sister chromatids joined at their centromeres. Paired homologous chromosomes, which were joined by synapsis, now form a tetrad of four chromatids. Where crossing over has occurred between nonsister chromatids, they are joined by X-shaped chiasmata.

pach·y·tene

(pak'i-tēn),
The stage of prophase in meiosis in which pairing of homologous chromosomes is complete and the paired homologues may twine about each other as they continue to shorten; longitudinal cleavage occurs in each chromosome to form two sister chromatids so that each homologous chromosome pair becomes a set of four intertwined chromatids.
Synonym(s): pachynema
[pachy- + G. tainia, band, tape]

pachytene

/pachy·tene/ (pak´ĭ-tēn) in the prophase of meiosis, the stage following zygotene during which the chromosomes shorten, thicken, and separate into two sister chromatids joined at their centromeres. Paired homologous chromosomes, which were joined by synapsis, now form a tetrad of four chromatids. Where crossing over has occurred between nonsister chromatids, they are joined by X-shaped chiasmata.

pachytene

(păk′ĭ-tēn′)
n.
The third stage of the prophase of meiosis, during which the homologous chromosomes become short and thick and divide into four distinct chromatids.

pachytene

[pak′itēn]
Etymology: Gk, pachy + tainia, ribbon
the third stage in the first meiotic prophase of gametogenesis, in which the paired homologous chromosomes form tetrads. The bivalent pairs become short and thick and intertwine so that four chromatids are visible. See also diakinesis, diplotene, leptotene, zygotene.

pach·y·tene

(pak'i-tēn)
The stage of prophase in meiosis in which pairing of homologous chromosomes is complete; longitudinal cleavage occurs in each chromosome to form two sister chromatids so that each homologous chromosome pair becomes a set of four intertwined chromatids.
[pachy- + G. tainia, band, tape]

pachytene

the stage in prophase 1 of MEIOSIS where the paired HOMOLOGOUS CHROMOSOMES each split into two CHROMATIDS, the whole structure being called a TETRAD.

pachytene

in prophase of meiosis, the stage following zygotene during which the chromosomes shorten, thicken and separate into two sister chromatids joined at their centromeres. Paired homologous chromosomes, which were joined by synapsis, now form a tetrad of four chromatids. Where crossing over has occurred between nonsister chromatids, they are joined by Y-shaped chiasmata.
References in periodicals archive ?
To this end, we first monitored the activation of the late pachytene meiotic checkpoint that leads to apoptotic clearing of nuclei carrying unrepaired DNA damage (Gartner et al.
In human pachytene spermatocytes, SUMO-1 and another factor that binds to DNA, known as a histone, show discrete patterns.
In a previous study, mammalian Pdcl2 was strongly detected in pachytene spermatocytes to early post-meiotic spermatids in the testis (Lopez et al.
Sertoli cells only contain [alpha]-subunits whereas the [beta]B-subunits are localized in pachytene spermatocytes and in round spermatids (38).
The genes SCP1 and XPA are expressed normally in the primary and pachytene spermatocyte stage, and protein encoded by the SSX gene is found normally in spermatogonia and primary spermatocytes, as well as in germ cells from the 17th week of intrauterine development.
After pachytene, bivalents have no chiasma; homologous chromosomes lie parallel to each other, and condense gradually during prophase I and metaphase I.
Background & objectives: The study was taken up to define criteria of normality for meiosis by assessing the frequency of meiotic prophase cell types, the frequency of pachytene substage in normal and abnormal spermatogenesis and to determine what synaptonemal complex.
6 [micro]m) is possible to see 4 stages of early prophase: leptotene, zygotene, pachytene and diplotene.
The population of preleptotene and pachytene spermatocytes were decreased by 64.