PMID- 9390269
OWN - NLM
STAT- MEDLINE
DCOM- 19971229
LR  - 20120531
IS  - 0914-7470 (Print)
IS  - 0914-7470 (Linking)
VI  - 10
IP  - 2
DP  - 1997 Jun
TI  - [Extending the capabilities of human chromosome analysis: from high-resolution 
      banding to chromatin fiber-FISH].
PG  - 121-34
AB  - The rapid development in human chromosome studies during the past 2 decades has 
      opened up a variety of new avenues in both basic and clinical human genetics. 
      This has been due to the extended resolution of chromosome analysis especially by 
      the introduction of high-resolution banding and fluorescence in situ 
      hybridization (FISH) techniques. High-resolution banding methods using elongated 
      chromosomes from cells at early mitotic stage can be divided into two main 
      categories: one involves S-phase synchronization using methotrexate or thymidine 
      with subsequent release from the block, and the other involves the application of 
      DNA-binding agents, such as ethidium bromide, which inhibit mitotic chromosome 
      condensation. High-resolution band analysis facilitates refined determination of 
      the breakpoints on rearranged chromosomes, and thus minute deletions, small 
      translocations and other subtle chromosome mutations can readily be detected and 
      identified. It has also proved to be valuable for accurate gene mapping and 
      comparative cytogenetics. Each of the high-resolution bands consists of DNA 
      molecules as long as approximately 3Mb on the average, and this resolution 
      limitation has been overcome by the introduction of the FISH method, which 
      enables chromosome and genomic analyses to be carried out at the DNA molecule 
      level. For FISH analysis, appropriate DNA probes of various insert sizes can be 
      chosen for different purposes, and FISH with specific probes permits 
      high-resolution analysis of chromosome DNA constitution at particular loci. For 
      instance, it is possible to detect and map unique sequences more than 1 kb in 
      size on mitotic chromosomes, and to identify cryptic chromosome rearrangements 
      not recognizable even by high-resolution band analysis. Better resolution of 
      breakpoint determination can also be expected by FISH using an adequate series of 
      DNA clones arrayed on the physical map within the relevant chromosome region. An 
      even better genomic resolution by FISH can be obtained by utilizing free 
      chromatin DNA fibers released from interphase nuclei as a hybrization target. The 
      FISH signals on the chromatin fiber preparations are shown to be "linear", unlike 
      the standard FISH signals that have a "dot" appearance, and the resolution 
      attainable should be comparable to analysis of a straight DNA double helix 
      itself. The degree of resolution in the so-called fiber-FISH method ranges from a 
      few to 300 kb, and thus the method can readily be applied to the high-resolution 
      assessment of ordering and overlapping of isolated DNA clones from a specific 
      chromosome region, as well as sizing of gaps between the clones. Fiber-FISH may 
      prove most valuable for the precise determination of breakpoints at the kilobase 
      level, and also for identifying minute deletions and duplications. By presenting 
      some examples of our own recent works, this review attempts to summarize the 
      current contribution of the above strategies in mediating the two separate ranges 
      of resolution achieved by the classical chromosome and molecular DNA analyses.
FAU - Ikeuchi, T
AU  - Ikeuchi T
AD  - Department of Cytogenetics, Medical Research Institute, Tokyo Medical and Dental 
      University, Japan.
LA  - jpn
PT  - English Abstract
PT  - Journal Article
PT  - Review
PL  - Japan
TA  - Hum Cell
JT  - Human cell
JID - 8912329
RN  - 0 (Chromatin)
SB  - IM
MH  - *Chromatin
MH  - Chromosome Banding/*methods
MH  - Chromosome Breakage
MH  - Chromosome Mapping
MH  - Humans
MH  - In Situ Hybridization, Fluorescence/*methods
MH  - Translocation, Genetic
RF  - 51
EDAT- 1997/06/01 00:00
MHDA- 1997/12/09 00:01
CRDT- 1997/06/01 00:00
PHST- 1997/06/01 00:00 [pubmed]
PHST- 1997/12/09 00:01 [medline]
PHST- 1997/06/01 00:00 [entrez]
PST - ppublish
SO  - Hum Cell. 1997 Jun;10(2):121-34.