chromosomal deletion


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Related to chromosomal deletion: Chromosomal inversion

chro·mo·som·al de·le·tion

a microscopically evident loss of part of a chromosome.
See also: monosomy.

chro·mo·som·al de·le·tion

(krō'mŏ-sō'măl dĕ-lē'shŭn)
A microscopically evident loss of part of a chromosome.
See also: monosomy

chromosomal

emanating from or pertaining to chromosome.

chromosomal aberration
see chromosomal abnormality (below).
chromosomal abnormality
abnormal karyotype; abnormalities can be detected before birth by means of amniocentesis, or after birth, but many are probably never observed because they cause death and disposal of the fetus. The abnormalities are either of number, or of composition of the individual chromosomes. Monosomy and trisomy are examples of numerical abnormalities. Translocations are examples of abnormalities of structure where parts of one chromosome have been transferred to another. The cause of these abnormalities is not known. Their importance is that many of them are linked with structural or functional defects of the animal body. The best known ones in veterinary medicine are those that are related to infertility, e.g. translocation 1/29, translocation 27/29.
chromosomal analysis
fetal cells obtained by amniocentesis or lymphocytes from a blood sample can be cultured in the laboratory until they divide. Cell division is arrested in mid-metaphase by the drug Colcemid, a derivative of colchicine. The chromosomes can be stained by one of several techniques that produce a distinct pattern of light and dark bands along the chromosomes, and each chromosome can be recognized by its size and banding pattern. The chromosomal characteristics of an animal are referred to as its karyotype. This also refers to a photomicrograph of a cell nucleus that is cut apart and rearranged so that the individual chromosomes are in order and labeled. The autosomes are numbered roughly in order of decreasing length. The sex chromosomes are labeled X and Y. Karyotyping is useful in determining the presence of chromosome defects.
chromosomal banding
see banding (2).
chromosomal chimerism
see chimera.
chromosomal crossover
chromosomal deletion
in genetics, loss from a chromosome of genetic material.
chromosomal inversion
see inversion (2).
chromosomal linkage
see linkage (2).
chromosomal mapping
see genetic map.
chromosomal non-disjunction
failure of the chromatids or chromosomes to separate (disjoin) during meiosis.
chromosomal replication
chromosomal walking
a technique for identification and isolation of contiguous sequences of genomic DNA.
chromosomal X inactivation
only one of a pair of female (X) chromosomes in the one cell is active, the other is inactivated.
References in periodicals archive ?
1996; Thiriot-Quievreux, 2002), while Ostreidae has a modal haploid number of 10; and (3) there is a general correlation between chromosome number and DNA content, and variations can be explained by chromosomal deletion, fusion, translocation, and limited duplication, as shown for Pectinidae in this study.
It has been used to identify signaling and metabolic pathways associated with tumor progression, as well as to detect submicroscopic chromosomal deletions and duplications in patients with mental retardation and other disabilities.
Researchers have learned that if chromosomal deletions or other genetic alterations rob a cell of the function of a tumor suppressor gene, that cell can ignore the strict regulations on cell growth and division that the body ordinarily imposes.
That year, they and four other parents started Chromosome Deletion Outreach, a matching group for all conditions caused by chromosomal deletions, additions and inversions.
We also performed the oriC and terminus localization studies in strains containing chromosomal deletions of the genes for the cytoskeletal MreB, MreC, and MreD proteins.
A correlation between the presence of multiple chromosomal deletions and poor survival has been reported (10).
Since chromosomal deletions are not limited to cancer-related genes alone, and may cause any number of unrelated neighbouring genes to be lost, the researchers had to pinpoint the tumour suppressors among the 300 genes.