If these structures are manipulated incorrectly, through processes known as chromosomal instability and translocation, the cell may undergo mitotic catastrophe and die, or it may unexpectedly evade apoptosis leading to the progression of cancer.

Crisis is characterized by gross chromosomal rearrangements and genome instability, and almost all cells die.

The diagnosis of A-T is usually suspected by the combination of neurologic clinical features ( ataxia, abnormal control of eye movement, and postural instability ) with telangiectasia and sometimes increased infections, and confirmed by specific laboratory abnormalities ( elevated alpha-fetoprotein levels, increased chromosomal breakage or cell death of white blood cells after exposure to X-rays, absence of ATM protein in white blood cells, or mutations in each of the person ’ s ATM genes ).

Nijmegen breakage syndrome ( NBS ) is a rare genetic disorder that has similar chromosomal instability to that seen in people with A-T, but the problems experienced are quite different.

Hypomethylation, in general, arises earlier and is linked to chromosomal instability and loss of imprinting, whereas hypermethylation is associated with promoters and can arise secondary to gene ( oncogene suppressor ) silencing, but might be a target for epigenetic therapy.

When cells enter mitosis, the sister chromatids ( which represent the two copies of each chromosomal DNA molecule resulting from DNA replication earlier in the cell cycle and packaged by histones and other proteins into chromatin ) are linked all along their length by the action of the cohesin complex.

* multiple copies of the same sequence, such as Alu sequences can hinder precise chromosomal pairing during mitosis and meiosis, resulting in unequal crossovers, one of the main reasons for chromosome duplication.

The mechanisms leading to novel variation in newly formed allopolyploids may include gene dosage effects ( resulting from more numerous copies of genome content ), the reunion of divergent gene regulatory hierarchies, chromosomal rearrangements, and epigenetic remodeling, all of which affect gene content and / or expression levels.

It is a characteristic phenotype resulting from a partial deletion of chromosomal material of the short arm of chromosome 4 ( del ( 4p16. 3 )).

Presence of certain chromosomal aberrations and their resulting fusion genes is commonly used within cancer diagnostics in order to set a precise diagnosis.

DSRCT is associated with a unique chromosomal translocation ( t11 ; 22 )( p13: q12 ) resulting in a EWS / WT1 transcript that is diagnostic of this tumor.

The pachytene stage, also known as pachynema, from Greek words meaning " thick threads ", is the stage when chromosomal crossover ( crossing over ) occurs.

In microbiology and genetics, a plasmid is a DNA molecule that is separate from, and can replicate independently of, the chromosomal DNA.

In bacteria, transposons can jump from chromosomal DNA to plasmid DNA and back, allowing for the transfer and permanent addition of genes such as those encoding antibiotic resistance ( multi-antibiotic resistant bacterial strains can be generated in this way ).

The core contains the spore chromosomal DNA which is encased in chromatin-like proteins known as SASPs ( small acid-soluble spore proteins ), that protect the spore DNA from UV radiation and heat.

Telomeres are regions of repetitive DNA at the end of a chromosome, which provide protection from chromosomal deterioration during DNA replication.

E. coli O157: H7 serotypes are closely related, descended from a common ancestor, divergent in plasmid content more than chromosomal content, and are no more related to other shiga toxin producing strains than any other randomly chosen E. coli serotype.

This prevents chromosomal fraying and prevents the ends of the chromosome from being processed as a double-strand DNA break, which could lead to chromosome-to-chromosome telomere fusions.

Amniocentesis ( also referred to as amniotic fluid test or AFT ) is a medical procedure used in prenatal diagnosis of chromosomal abnormalities and fetal infections, in which a small amount of amniotic fluid, which contains fetal tissues, is sampled from the amnion or amniotic sac surrounding a developing fetus, and the fetal DNA is examined for genetic abnormalities.

The disorder may stem from a wide variety of conditions that cause abnormal growth of the brain, or from syndromes associated with chromosomal abnormalities.

Technologies such as genomic microarrays, also called array comparative genomic hybridization ( array CGH ), are used to detect chromosomal abnormalities, such as microduplications, in a high throughput fashion from genomic DNA samples.

These differences in plumage result from a balanced chromosomal inversion polymorphism ; in white-striped ( WS ) birds, one copy of chromosome 2 is partly inverted, while in tan-striped ( TS ) birds, both copies are uninverted.

DNA is examined from microsatellites within the chromosomal DNA.

But genetic recombination ( chromosomal crossover ) mixes genes from non-sister chromatids from both parents during meiosis, thus muddling the ancestry path.

This chromosomal abnormality is so named because it was first discovered and described in 1960 by two scientists from Philadelphia, Pennsylvania, USA: Peter Nowell of the University of Pennsylvania and David Hungerford of Fox Chase Cancer Center.

One of the drivers of the progression from chronic phase through acceleration and blast crisis is the acquisition of new chromosomal abnormalities ( in addition to the Philadelphia chromosome ).

Male tortoiseshell or calico cats occur only if they have chromosomal abnormalities such as the genotype XXY ( in which case they are sterile ), chromosomal mosaicism ( only portions of their cells have the genotype XXY, so these cats may be fertile ), or chimericism ( a single individual formed from two fused embryos, at least one of which was male ).

Such versatility of the breeding system together with chromosomal repatterning, hybridization, polyploidy and vegetative multiplication / apomixis explains the origin and preservation of an astonishing range in chromosome numbers from 2n = 18 to 96 in this genus.

Bcl-2 derives its name from B-cell lymphoma 2, as it is the second member of a range of proteins initially described in chromosomal translocations involving chromosomes 14 and 18 in follicular lymphomas.

24-Epibrassinolide ( EBL ), a brassinosteroid isolated from Aegle marmelos Correa ( Rutaceae ), was further evaluated for the antigenotoxicity against maleic hydrazide ( MH )- induced genotoxicity in Allium cepa chromosomal aberration assay.

The genetic basis of the phenotypic differences between the two strains results from coding, regulatory, and insertion / deletion polymorphisms at five chromosomal loci.

One of the most important features of the C. albicans genome is the occurrence of numeric and structural chromosomal rearrangements as means of generating genetic diversity, named chromosome length polymorphisms ( contraction / expansion of repeats ), reciprocal translocations, chromosome deletions and trisomy of individual chromosomes.

# The disorder is not a symptom of another mental disorder or a chromosomal abnormality

Penrose went on to identify and study many of the genetic and chromosomal causes of mental retardation ( then called mental deficiency ).

** 1 or more unexplained deaths of a morphologically normal fetus ( documented by ultrasound or direct examination of the fetus ) at or beyond the 10th week of gestation and / or 3 or more unexplained consecutive spontaneous abortions before the 10th week of gestation, with maternal anatomic or hormonal abnormalities and paternal and maternal chromosomal causes excluded or at least 1 premature birth of a morphologically normal neonate before the 34th week of gestation due to eclampsia or severe pre-eclampsia according to standard definitions, or recognized features of placental insufficiency plus

Some other possible features present in cloning vectors are: vir genes for plant transformation, integrase sites for chromosomal insertion, lacZα fragment for α complementation and blue-white selection, and / or reporter genes in frame with and flanking the MCS to facilitate the production of recombinant proteins fused to the Green fluorescent protein ( GFP ) or to the glutathione S-transferase ( see figure ).

A traditional exam involving metaphase chromosome analysis is often unable to identify features that distinguish one disease from another, due to subtle chromosomal features ; FISH can elucidate these differences.

In this chromosomal abnormality, several features combine to make the presence of obstructive sleep apnea more likely.

Edmund Beecher Wilson and Nettie Stevens are credited with discovering, in 1905, the chromosomal XY sex-determination system ; the fact that males have XY sex chromosomes and females have XX sex chromosomes.

Humans, as well as some other organisms, can have a chromosomal arrangement that is contrary to their phenotypic sex, that is, XX males or XY females.

* Individuals with a male phenotype and an XX ( female ) karyotype — XX male syndrome — have been observed ; these males have the SRY gene in one or both X chromosomes ( or possibly on an autosome ), moved there by chromosomal translocation.

He also discovered the chromosomal XY sex-determination system in 1905 — that males have XY and females XX sex chromosomes.

Genetic factors can cause pretesticular, testicular, and posttesticular azoospermia ( or oligospermia ) and include the following situations: The frequency of chromosomal abnormalities is inverse proportional to the semen count, thus males with azoospermia are at risk to have a 10-15 % abnormalities on karyotyping versus about < 1 % in the fertile male population.