Chromosome characteristics

Meiosis A spedal method of cell division, occurring in maturation of the germ cells, by means of which each daughter nucleus receives half the number of chromosomes characteristic of the somatic cells of the species. [NIH]... 

Jaundice. A syndrome characterized by hyperbilirubinemia (excessive concentrations of bilirubin in the blood) and deposition of bile pigment in the skin, mucous membranes, and sclera with resulting yellow appearance of the patient Karyotype. The chromosome characteristics of an individual or of a cell line, usually presented as a systematized array of metaphase chromosomes from a photomicrograph of a single cell nucleus arranged in pairs in descending order of size and according to the position of centromere. 

Silverman J, Kline J, Hutzler M (1985) Maternal employment and the chromosomal characteristics of spontaneously aborted conceptions. J Occup Med. 27 427-438. 

The protein expression patterns obtained by 2-DE in B cell chronic lymphocytic leukaemia was also studied by T. Voss and collaborators in 24 patient samples (Voss et al, 2001). This analysis allowed the identification of proteins that clearly discriminated between different patient groups (with defined chromosomal characteristics or according to clinical parameters). More particularly, this study showed that B cell chronic lymphocytic leukaemia patients with shorter survival exhibit changed levels of redox enzymes such as heat shock protein 27 and protein disulfide isomerase. 

Krai, B. 1971. Chromosome characteristics of certain Murine Rodents (Muridae) of the Asiatic part of the USSR. Zool. Listy, 331-347. 

Notice the presence of several submetacentrics and many small biarmed chromosomes. (c) Metaphase of hybrid DC. Notice the presence of chromosomes characteristic of both parents, including the D chromosome (arrow). 

The discovery by Barski, Sorieul and Comefert (1960) of the occurrence of hybridization in mixed cultures of two permanent mouse lines, the hybrid cells being recognized karyologically, by the presence of chromosomes characteristic of both parental cell types. 

Genes are segments of chromosomes. Some of the genes are coded to give each animate species its characteristics (e.g., color and number of eyes, type of hair, muscle), and others are coded to produce the chemicals required for the organism to live (metabolism). 

Ultimately a plasmid is defined by its mode of DNA repHcation. DNA repHcation is initiated at a single, characteristic sequence, termed the origin. The origin sequence determines the copy number of the plasmid relative to the host chromosome and the host enzymes that are involved in plasmid repHcation. Two different plasmids that contain the same origin sequence are termed incompatible. This term does not refer to the active exclusion of one plasmid by another from the ceU but rather to a stochastic process by which the two plasmids are partitioned differentially into progeny ceUs. A ceU which contains two plasmids of the same incompatibiHty group segregates two clonal populations, each of which has one of the two plasmids in it. 

The packaging of nucleoproteins within chromatids is not random, as evidenced by the characteristic patterns observed when chromosomes are stained with specific dyes such as quinacrine or Giemsa s stain (Figure 36-6). 

From individual to individual within a single species, the pattern of staining (banding) of the entire chromosome complement is highly reproducible nonetheless, it differs significantly from other species, even those closely related. Thus, the packaging of the nucleoproteins in chromosomes of higher eukaryotes must in some way be dependent upon species-specific characteristics of the DNA molecules. 

The major Impetus to the development of methods for the prenatal detection of genetic disorders derives. In historical terms, from the roughly simultaneous development of three major techniques (11-14). One was the technique, and the willingness to use It, for obtaining samples of amnlotlc fluid early In gestation. The second was the development of techniques for the culture of human cells in vitro, and the third was the development of better techniques for cytogenetic analysis. As will be described below, with the availability of these three techniques It became possible first to work out methods for the examination of fetal chromosomes, and then, by extension, to devise ways of determining other characteristics of the fetus. 

Uncultured cells have also been used to a limited extent for fetal sex determination. This Is possible because the cells can be appropriately stained and examined for the presence of sex chromatin, characteristic of female cells, and for the fluorescent Y-body, characteristic of male cells (33,34). However, these cytologic techniques are not completely reliable, and It Is still desirable to determine fetal sex by direct chromosome analysis (35). 

Specific pathologic characteristics distinguishing Hodgkin s lymphoma from non-Hodgkin s lymphoma include morphology, cell surface antigens, and chromosomal mutations. 

For patients with myelodysplastic syndrome or AML as a secondary neoplasm, there are a number of key features characteristic of the leukemia. Alkylator-related secondary leukemias after Hodgkin s disease usually have a myelodysplastic prodrome and a monosomy 5 or monosomy 7. Secondary ANLL with the use of epipodophyllotoxin (etoposide) demonstrates mainly M4 or M5 morphology and exhibits translocations within the MLL gene with 1 lq23 chromosomal alterations.8... 

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