Chromosome arms

FIG. 3. Chromosome arms begin to separate in pro metaphase. Scanning electron micrographs of human chromosomes isolated from cells in prophase (A), prometaphase (B), metaphase (C) and early anaphase (insert in C). Size bar, 1 /tm. Reprinted with permission from Sumner (1991). 

Waizenegger IC, Hauf S, Meinke A, Peters J-M 2000 Two distinct pathways remove mammalian cohesin from chromosome arms in prophase and from centromeres in anaphase. Cell 103 399—... 

The arm of the chromosome. Each chromosome is divided into two sections (arms) based on the location of a narrowing (constriction) called the centromere. By convention, the shorter arm is called p, and the longer arm is called q. The chromosome arm is the second part of the gene s address. For example, 5q is the long arm of chromosome 5, and Xp is the short arm of the X chromosome. 

Smith JS, Perry A, BorellTJ, etal. Alterations of chromosome arms lpand 19q as predictors of survival in oligodendrogliomas, astrocytomas, and mixed oligoastrocytomas. J Clin Oncol 2000 18 636-645. 

Lastowska M, Cotterill S, Pearson AD et al. Gain of chromosome arm 17q predicts unfavourable outcome in neuroblastoma patients. U.K. Children s Cancer Study Group and the U.K. Cancer Cytogenetics Group. EurJCancer 1997 33 1627-1633. 

A,2B 2 long arm, 10 long arm Finger millet LG 10, which spans 16.5 cM four markers with homology to sequences on rice chromosome arm 2S... 

Bell DW, Jhanwar SC, Testa JR. 1997. Multiple regions of allelic loss from chromosome arm 6q in malignant mesothelioma. Cancer Res 57 4057-4062. 

Parelho V, et al. Cohesins Functionally associate with CTCF on mammalian chromosome arms. Cell 2008 132 422-433. 

Tanaka T, et al. Identification of cohesin association sites at centromeres and along chromosome arms. Cell 1999 98 847-858. 

Micci F, Walter CU, Teixeira MR, et al. Cytogenetic and molecular genetic analyses of endometrial stromal sarcoma Nonrandom involvement of chromosome arms 6p and 7p and confirmation of JAZFl/JJAZl gene fusion in t(7 17). Cancer Genet Cytogenet. 2003 144 119-124. 

The medulloblastoma is a CNS primitive neuroectodermal tumor (cPNET) in the cerebellum. The most frequent genetic abnormality associated with medulloblastoma is loss of chromosome arm 17p. This is often seen as an isochromosome 17q (one chromosome composed... 

Burnett ME, White EC, Sih S. Chromosome arm 17p deletion analysis reveals molecular genetic heterogeneity in supratentorial and infratentorial primitive neuroectodermal tumors of the central nervous system. Cancer Genet Cytogenet. 1997 97 25-... 

Most satellite DNA is composed of repeats of 14-500 base pairs in tandem repeats of 20-100 kb. In situ hybridization studies with metaphase chromosomes have localized these satellite DNAs to specific chromosomal regions. In most mammals, much of this satellite DNA lies near centromeres, the discrete chromosomal regions that attach to spindle microtubules during mitosis and meiosis. Satellite DNA is also located at telomeres, the ends of chromosomes, and at specific locations within chromosome arms in some organisms. These latter sequences can be useful for identifying particular chromosomes by fluorescence in situ hybridization (FISH), as Illustrated in Figure 10-5. 

Figure 7.26. Chromosome distribution of the H3 and LI bands. Ideogram of human chromosomes al 850-band resolution showing the position of the 1.1 (blue) and the H3 (red) bands as previously identified on the basis of the concentration of LI and H3 isochores, respectively. This figure shows that the gcnc-riohesi. GC-riohesl, H,3 bands are prevalently located distally on each chromosome arm and are generally not adjacent to the gene-poorcst, GC-poorest, bands, which are prevalently located more proximally. The in termed iate bands (M3, LI ) are lei) uncolorcd in order to emphasize this spacing. (From Saccone...

Figure 7,27. A carioon showing that the cemromeric proximal regions of chromosomes tend to be present in compact chromatin structures at the periphery of the imerphase nucleus (blue blocks), whereas the distal regions are in an open chromatin structure (red filaments) in the tenter of the nucleus. Only two chromosomes ate depicted. In this simplified drawing entire chromosome arms arc represented as completely open. More realistically, the open chromatin loops should concern a number of regions from each chromosome arm.

Also they differ in amino acid composition from the gluten proteins, possessing lower amounts of glutamic acid and more lysine. Unfortunately, because they are present in the wheat endosperm in minor proportions, their presence it is not enough to overcome the lack of lysine in wheat. Analysis of aneuploid stocks of the wheat variety Chinese Spring has revealed that the HMW albumins of 69,63,60, and 45 kDa are controlled by genes on the chromosome arms 4DL, 4AL, SAL and SDL respectively. 

Fig. 6.37. Two approaches for manipulation of a human chromosome. (A) Minichromosomes can be generated in cultured cells by chromosome truncation mediated by the integration of telomeric sequences into chromosome arms. (B) Alternatively, artificial chromosomes might be constructed by combining the known functional elements of a human chromosome telomeric DNA, centromeric DNA, and genomic DNA containing a human gene or selectable genetic marker.

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