Two subsets of human alphoid repetitive DNA show distinct preferential localization in the pericentric regions of chromosomes 13, 18, and 21

Abstract

We have isolated and characterized two human middle repetitive alphoid DNA fragments, L1.26 and L1.84, which localize to two different sets of chromosomes. In situ hybridization revealed both repeats to have major and minor binding sites on the pericentric regions of several chromosomes. Probe L1.26 maps predominantly to chromosomes 13 and 21. Probe L1.84 locates to chromosome 18. Minor hybridization sites for both probes include chromosomes 2, 8, 9, and 20; in addition, L1.26 revealed minor sites on chromosomes 18 and 22. The binding to these sites strongly depends on hybridization conditions. In Southern blot hybridizations to total human DNA, both L1.26 and L1.84 give the same ladder pattern, with a step size of 170 bp, indicating their presence as tandem repeats, but with different band intensities for each probe. The chromosome-specific nature of particular multimers was confirmed by Southern blot analyses of a human-rodent hybrid cell panel. We conclude that L1.26 and L1.84, with their related sequences, constitute subfamilies of alphoid DNA that are specific for subsets of chromosomes and, in some cases, possibly even for single chromosomes.

True

“…18 (L1.84). 25 Probe pAE0.68 was labelled with digoxigenin-11-dUTP while all other probes were labelled with biotin-11-dUTP by means of standard nick-translation of complete plasmid DNA, according to the manufacturer's directions (Boehringer Mannheim).…”

Detection of chromosome aberrations in the human interphase nucleus by visualization of specific target DNAs with radioactive and non-radioactive in situ hybridization techniques: diagnosis of trisomy 18 with probe L1.84

“…Evidence is accumulating that the sequence heterogeneity within this family is distributed in a chromosome specific manner, so that each individual chromosome may be characterized by the presence of its own distinct alphoid DNA subfamily (Wolfe et al 1985;JCrgensen et al 1986). Alphoid subfamilies may display a characteristic restriction-site spacing, which would allow their detection in Southern blot experiments (Willard 1985;JCrgensen 1986;Devilee et al 1986b). Clone L1.84 represents such a subfamily on chromosome 18.…”

“…Our data indicate that the number of chromosomes 18 present in human interphase nuclei can be reliably detected under these conditions. Evaluation of a small number of cell nuclei is sufficient to discriminate between a normal cell population and a cell population (Devilee et al 1986b). After a further decrease of stringency hybridization signals become apparent over the centromeric heterochromatin of all chromosomes.…”

“…While further investigations of the chromosomal distribution of different distinct alphoid subfamilies and their molecular relationships are intriguing with regard to questions of chromosomal evolution in men and monkeys, their use as a diagnostic tool in "interphase cytogenetics" (see below) is limited by the fact that their occurrence seems to be largely restricted to the constitutive human heterochromatin. Furthermore, identical sequences from a given subfamily may likely occur (Mitchell et al 1986;Devilee et al 1986b).…”

Gain and loss of chromosomes 1, 7, 8, 10, 18, and Y in 46 prostate cancers

“…This is because of selective isolation and preferential in vitro growth of nonmalignant prostate epitheliumY The use of interphase cytogenetic techniques for characterization of uncultured PC material has been stimulated by these findings. Application of in situ hybridization with centromere-specific DNA probes to fixed sections of PC has shown numerical aberrations for chromosomes 1,7,8,10,12,17,18, X, and y4~7 The finding of numerical aberrations in different chromosomes is not surprising because about 50% of the PCs have an aneuploid DNA content. 8 In the present study, the authors investigated numerical changes of chromosomes 1,7,8,10,18, and Y using fluorescence in situ hybridization (FISH) with centromere-specific DNA probes on nuclear suspensions of fresh tissue samples from 11 benign prostatic hyperplasia (BPH) and 43 PC patients.…”