Chromosome banding

Fluorescence in situ hybridization Permits localization of a gene to one chromosomal band. 

F15. Furuta, H., Nishi, S., Le Beau, M. M., Femald, A. A., Yano, H., and Bell, G. I Sequence of human hexokinase HI cDNA and assignment of the human hexokinase m gene (HK3) to chromosome band 5q35.2 by fluorescence in situ hybridization. Genomics 36,206-209 (1996). 

Yasuda K, Espinosa R, Takeda J, Le Beau M, Bell GI. Localization of the kappa opioid receptor gene to human chromosome band 8qll.2. Genomics 1994 19 596-597. 

Hori T, Takahashi E, Ayusawa D, Takeishi K, Kaneda S, Seno T. Regional assignment of the human thymidylate synthase (TS) gene to chromosome band 18pll.32 by nonisotopic in situ hybridization. Hum Genet 1990 8 576-580. 

Alternatively, DNA on the slide can be hybridized with probe, followed by staining to effect chromosome banding. Fluorescence of the hybridized region can be photographed and mounted to serve as a permanent record. 

Table 1 lists representative examples of the application of in situ hybridization, including FISH, to studies that use chromosome preparations and interphase nuclei (4,5). FISH is superior to in situ hybridization with an enzymatic probe because it provides finer resolution and higher signal intensity. This is especially important when the localization of a gene within a specific chromosome band is to be established. 

Caron H, Peter M, van Sluis P et al. Evidenee for two tumor suppressor loci on chromosomal bands lp35-36 involved in neuroblastoma one probably imprinted, another associated with A-myc amplification. HumMolec Genet 1995 4 535-539. 

The TS gene is localized to the short arm of chromosome 18 at chromosome band 18p 11.32 (64). Chromosome 18 is generally known to be a site of frequent deletions in colorectal cancer tissues (64). Therefore it is highly probably that allelic imbalance occurs at the TS locus in some colorectal tumors. Zinzindohoue et al. were the first to report on the idea of LOH at the TS locus. The authors showed that the TS genotype from 2R/3R heterozygotes differed in ratio between 2R and the 3R bands. The observed LOH frequency at the TS locus was 63% (31 of 50) (65). 

Given a cloned fragment of a Drosophila gene, how could you determine which chromosomal band(s) contain the gene ... 

The human kallikrein locus contains a unique minisatellite element that is restricted to chromosomal band 19ql3, and ten clusters of this minisatellite are distributed along the kallikrein locus. These clusters are mainly located... 

Le Coniat M, Kinet JP, Berger R. The Human genes for the alpha and gamma subunits of the mast cell receptor for immunoglobulin E are located on human chromosome band lq23. Immunogenetics 1990 32(3) 183—186. 

Chromosome banding is evident when chromosomes are treated with chemical dyes, such as Giemsa chromosomes appear as a series of alternate dark (G-band or G-positive band) and... 

Figure 19.1 During the metaphase of cell division, a chromosome becomes two sister chromatids attached at the centromere. Chromosome banding exemplified using human chromosome 17.

Cheng JQ, Lee W-C, Klein MA, et al. 1999a. Frequent mutations of NF2 and allelic loss from chromosome band 22ql2 in malignant mesothelioma Evidence for a two-hit mechanism of NF2 inactivation. Genes Chromosomes Cancer 24 238-242. 

El Achkar E, Gerbault-Seureau M, Muleris M, Dutrillaux B, Debatisse M. Premature condensation induces breaks at the interface of early and late replicating chromosome bands bearing common fragile sites. Proc. Natl. Acad. Sci. U.S.A. 2005 102 18069-18074. 

The image below (Fig. 4.27) showing the presence of transcription factors interacting with Drosophila chromosomes would have been impossible to obtain since at higher expression levels the nucleus is filled with GFP-transcription factor which overshadows the chromosomal bands. 

Gytogenetic abnormalities in DMD patients and DNA linkage studies localized the DMD locus to Xp21 (the short arm of the X chromosome band 21)." Mixing DNA enhanced for X-linked genes from a 49,XXXXY cell fine with DNA... 

B33. Board, P. G., and Webb, G. C., Isolation of a cDNA clone and localization of human glutathione S-transferase 2 genes to chromosome band 6pl2. Proc. Natl. Acad. Sci U.SA. [PV3] 84, 2377-2381 (1987). 

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