1.1Genetics (of a chromosome) having no centromere.
〔遗传〕（染色体）无着丝粒的
Example sentencesExamples
In metaphase, chromatid fragments are attached to the homologous area of the sister chromatid while acentric chromosome fragments are apart from their chromosome of origin.
This classification method uses anti-kinetochore antibody staining to identify the presence of kinetochore protein associated with the centromeres of chromosomes or its absence from acentric chromosome fragments.
Micronuclei are acentric chromosome fragments or whole chromosomes that are left behind during mitotic cellular division and appear in the cytoplasm of interphasic cells as small additional nuclei.
The analysis of structural aberrations included chromatid and chromosome breaks, appearance of acentric fragments, dicentric chromosomes and chromatid exchanges (tetraradius forms).
Other aberrations, such as minutes, acentric rings, dicentrics and exchanges, were rarely seen.
Further, the products of crossovers between inverted repeats may lead to dicentric and acentric chromosomes that often cannot be transmitted to the next generation.
However, not all acentric chromosomes and dicentric chromosomes/centric rings were converted to MNi and NPB respectively, depending on the dose of radiation.
This paper describes an analysis of the frequency of dicentric chromosomes and acentric fragments in 1260 subjects occupationally exposed to X-rays and 241 controls.
They are formed by acentric chromosome fragments or whole chromosomes which are not incorporated into daughter nuclei during cell division.
A dicentric chromosome plus an acentric fragment were scored as one single aberration.
Six structurally acentric chromosomes were generated from the irradiation of Dp 238, supporting the findings of a previous study.
Ectopic crossing over causes chromosomal abnormalities, including deletions, translocations, and acentric and dicentric chromosomes.
Also excluded are exchanges that would generate dicentric or acentric chromosomes, such as exchanges that may occur between rDNA subunits lying in opposite orientation.
The first numeral refers to the chromosome providing the centromere-carrying segment, the second to the chromosome supplying the acentric segment.
Micronuclei can arise from acentric chromosome fragments or whole chromosomes that have not been incorporated in the main nuclei at cell division.
Micronuclei may originate from an acentric chromosome fragment or whole chromosomes lost from the metaphase plate and provide therefore a measure of both chromosome breakage and chromosome loss.
Micronuclei may originate from acentric chromosome fragments or whole chromosomes lagging behind during cell division.
Dicentrics, rings, acentric fragments and asymmetrical translocations were recorded separately.
These data further support the idea that the observed micronuclei result from preferential exclusion of acentric DNA fragments.