chiasma


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chiasma

(kīăz`mə): see crossing overcrossing over,
process in genetics by which the two chromosomes of a homologous pair exchange equal segments with each other. Crossing over occurs in the first division of meiosis. At that stage each chromosome has replicated into two strands called sister chromatids.
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chiasma

[kī′az·mə]
(anatomy)
A cross-shaped point of intersection of two parts, especially of the optic nerves.
(cell and molecular biology)
The point of junction and fusion between paired chromatids or chromosomes, first seen during diplotene of meiosis.
References in periodicals archive ?
These results may be interpreted as follows: the predominant reason for VA reduction in the patients with compressive optic neuropathies is ischemia of nerve fibers, which is more efficiently repaired after cranial surgery with a better microcirculation recovery after chiasma or optic nerve decompression in younger individuals than in older patients with meningiomas [15].
Extra clinical studies for octreotide capsules will also be performed by Chiasma to support sanction in the European Union and advance new product candidates based on its proprietary Transient Permeability Enhancer (TPEA) technology into preclinical development.
2001), the occurrence of non-terminalization of chiasma or the presence of chromosome stickiness is a factor that competes for the formation of chromosome bridges which may persist until telophase or break down, forming micronuclei.
A few eponyms are named after him: Camper's facial angle, Camper's chiasma, Tendinous chiasm of the digital tendons.
At the same time, she found her spiritual home at the University's Business School, where she was inaugural chief executive of Spark, the student-led entrepreneurship Challenge, and the founder and first chief executive of Chiasma for enterprising science students and graduates.
Gadolinium contrast enhanced MRI revealed the three masses of CT scan to be single mass involving the optic nerves, optic chiasma and extending along optic tract on both sides.
Magnetic resonance imaging (MRI) of the sellar area revealed a large intrasellar mass with a dimension of 15x14x12mm that extended to the suprasellar cisterns, with thickening of the infundibular stalk and elevating optic chiasma.
Depth, which only appears when it is paired with given surfaces, points attention toward a chiasma of formless color and screen design.
In another study on neuroepithelial cells migration in mice subsequent poisoning with vincristine during pregnancy has been expressed that this drug can cause abnormalities in the cephalic fold and optic chiasma which is seen from blight to Asymmetric growth [17].
This indicates that there are structural restrictions to chiasma formation in the holokinetic chromosomes.
Chiasma is developing technology that could enable oral delivery of protein- and peptide-based drugs that are available only by injection or intravenous methods.
The larger and the medium-sized bivalents may show two terminal chiasmata or a single terminal or sub-terminal chiasma; while the small bivalents only have one terminal chiasma (Figs.