The distribution of interspersed repetitive DNA sequences in the human genome

Fluorescence in situ hybridization to metaphase chromosomes or chromatin fibers In Interphase nuclei is a powerful technique in mapping genes and DNA segments to specific chromosome region. We have been able to release the chromatin fibers from cells arrested at GI and G2 phases using different drugs and a simple alkailne lysis procedure. We have also demonstrated specific hybridization of fluorescencelabeled probes to single-copy genoic DNA sequences on the free chromatins. Fluorescence in situ hybridztion signals have been detected for sequences separated as close as 21 klobase pairs and as far as 350 kilobase pairs, with excellent correspondence between the observed and expetd distances. The resolution of this technique should approach 10 kilobase pairs and its coverage should span millions of base pairs. Therefore, free chromatin mapping can be generally used to study the structure and organization of mammalian genomes.

show abstract

“…The discontinuous hybridization patterns observed are probably due to the uneven distribution of repetitive DNA along human chromosomes (14).…”

Section: Resultsmentioning

confidence: 99%

High-resolution mapping of mammalian genes by in situ hybridization to free chromatin.

Heng

Squire

Tsui

1992

Proc. Natl. Acad. Sci. U.S.A.

494

305

View full text Add to dashboard Cite

show abstract

“…The Alu-PCR products of line GM10888 did not label the centromeric region or the short arm of chromosome 22 (Fig. 1D), most likely because of an underrepresentation of Alu sequences in this region (8); hence, there is no crosshybridization to the other acrocentric chromosomes. The L1-PCR products of GM10888 label the entire chromosome 22, again generating a banding pattern, including the short arm of 22 (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…By using Alu-DNA as the probe, a pattern of hybridization signals similar to negative Giemsa banding is produced (6)(7)(8).…”

mentioning

confidence: 99%

Fluorescence in situ hybridization with Alu and L1 polymerase chain reaction probes for rapid characterization of human chromosomes in hybrid cell lines.

Lichter

Ledbetter

et al. 1990

Proc. Natl. Acad. Sci. U.S.A.

171

View full text Add to dashboard Cite

Human-rodent hybrid cell lines have been analyzed with regard to their human DNA content by using various DNA probe sets, derived from the hybrids, for in situ hybridization to normal human metaphase chromosome spreads. Total genomic hybrid DNA was compared with probe sets of hybrid DNA that were highly enriched in human sequences. The latter probes were obtained by amplification through the polymerase chain reaction (PCR) using oligonucleotide primers directed to human specific subsequences of the interspersed repetitive sequences Alu and Li. Previously unidentified chromosomal material within hybrid lines was characterized with speed and precision. It is demonstrated that the complete human complement of hybrid lines can be rapidly assessed by comparing the data obtained with the Alu-PCR products with the results from the L1-PCR products or from the genomic hybrid DNA. This approach using interspersed repetitive sequence-PCR products is simple and fast and also provides an alternative way of generating complex DNA probe sets for the specific delineation of entire chromosomes or subchromosomal regions by in situ hybridization.Human-rodent somatic cell hybrid lines are very important tools for the analysis of the human genome. In all applications it is crucial to know the complete human chromosomal complement of these lines. The lines are often unstable with regard to chromosomal content and arrangement and, therefore, require periodical re-examinations. Biochemical analysis or Southern blot analysis using large sets of DNA probes is labor-intensive and, in general, an exact determination of the human DNA content is not feasible with these methods. To obtain comprehensive data, cytogenetic analysis is the method of choice. G11 staining of metaphase chromosomes is used to differentiate human from rodent chromosomes on the basis of color (1), but G11 staining is of limited use for the accurate identification of the human chromosomal material.

show abstract

“…DNA probes for interspersed repetitive elements cause distinet banding patterns on metaphase chromosomes [11, 85,86] and can be used to produce a simultaneous in situ hybridization banding profile. Alu repeats, which also generate an R-banding-like pattern [87][88][89], are very useful for human chromosome identification. Both cloned Alu sequences [11] and PCR produets generated from an Alu primer [86] have been reported.…”

Section: Rapid Mapping Of Dna Sequencesmentioning

confidence: 99%