Mapping simple repeated DNA sequences in heterochromatin of Drosophila melanogaster.

Abstract Heterochromatin in Drosophila has unusual genetic, cytological and molecular properties. Highly repeated DNA sequences (satellites) are the principal component of heterochromatin. Using probes from cloned satellites, we have constructed a chromosome map of 10 highly repeated, simple DNA sequences in heterochromatin of mitotic chromosomes of Drosophila melanogaster. Despite extensive sequence homology among some satellites, chromosomal locations could be distinguished by stringent in situ hybridizations for each satellite. Only two of the localizations previously determined using gradient-purified bulk satellite probes are correct. Eight new satellite localizations are presented, providing a megabase-level chromosome map of one-quarter of the genome. Five major satellites each exhibit a multi-chromosome distribution, and five minor satellites hybridize to single sites on the Y chromosome. Satellites closely related in sequence are often located near one another on the same chromosome. About 80% of Y chromosome DNA is composed of nine simple repeated sequences, in particular (AAGAC)n (8 Mb), (AAGAG)n (7 Mb) and (AATAT)n (6 Mb). Similarly, more than 70% of the DNA in chromosome 2 heterochromatin is composed of five simple repeated sequences. We have also generated a high resolution map of satellites in chromosome 2 heterochromatin, using a series of translocation chromosomes whose breakpoints in heterochromatin were ordered by N-banding. Finally, staining and banding patterns of heterochromatic regions are correlated with the locations of specific repeated DNA sequences. The basis for the cytochemical heterogeneity in banding appears to depend exclusively on the different satellite DNAs present in heterochromatin.

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Repeated DNA Sequences in the Heterochromatic Y Chromosome of Adult Drosophila melanogaster

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.70.3.773 ◽

1973 ◽

Vol 70 (3) ◽

pp. 773-777 ◽

Cited By ~ 7

Author(s):

W. J. Perreault ◽

B. P. Kaufmann ◽

H. Gay

Keyword(s):

Drosophila Melanogaster ◽

Y Chromosome ◽

Dna Sequences ◽

Repeated Dna ◽

Repeated Dna Sequences ◽

Adult Drosophila

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The molecular structure, chromosomal organization, and interspecies distribution of a family of tandemly repeated DNA sequences of Antirrhinum majus L.

Genome ◽

10.1139/g96-033 ◽

1996 ◽

Vol 39 (2) ◽

pp. 243-248 ◽

Cited By ~ 7

Author(s):

Thomas Schmidt ◽

Jörg Kudla

Keyword(s):

In Situ Hybridization ◽

Dna Sequences ◽

Satellite Dna ◽

Antirrhinum Majus ◽

Repeated Dna ◽

Satellite Dnas ◽

Repeated Dna Sequences ◽

The North ◽

Tandemly Repeated Dna

Monomers of a major family of tandemly repeated DNA sequences of Antirrhinum majus have been cloned and characterized. The repeats are 163–167 bp long, contain on average 60% A + T residues, and are organized in head-to-tail orientation. According to site-specific methylation differences two subsets of repeating units can be distinguished. Fluorescent in situ hybridization revealed that the repeats are localized at centromeric regions of six of the eight chromosome pairs of A. majus with substantial differences in array size. The monomeric unit shows no homologies to other plant satellite DNAs. The repeat exists in a similar copy number and conserved size in the genomes of six European species of the genus Antirrhinum. Tandemly repeated DNA sequences with homology to the cloned monomer were also found in the North American section Saerorhinum, indicating that this satellite DNA might be of ancient origin and was probably already present in the ancestral genome of both sections. Key words : Antirrhinum majus, satellite DNA, repetitive DNA, methylation, in situ hybridization.

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Breakage of the human Y-chromosome short arm between two blocks of tandemly repeated DNA sequences

Genomics ◽

10.1016/0888-7543(89)90101-8 ◽

1989 ◽

Vol 5 (1) ◽

pp. 153-156 ◽

Cited By ~ 8

Author(s):

Ulrich Müller ◽

Marc Lalande ◽

Timothy A. Donlon ◽

Michael W. Heartlein

Keyword(s):

Y Chromosome ◽

Dna Sequences ◽

Repeated Dna ◽

Repeated Dna Sequences ◽

Human Y Chromosome ◽

Tandemly Repeated Dna

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Functional analysis of a centromere from fission yeast: a role for centromere-specific repeated DNA sequences.

Molecular and Cellular Biology ◽

10.1128/mcb.10.5.1863 ◽

1990 ◽

Vol 10 (5) ◽

pp. 1863-1872 ◽

Cited By ~ 50

Author(s):

L Clarke ◽

M P Baum

Keyword(s):

Dna Sequences ◽

Inverted Repeat ◽

Repeated Sequence ◽

Repeated Sequences ◽

Central Core ◽

Repeated Dna ◽

Inverted Repeat Region ◽

Repeated Dna Sequences ◽

Centromere Function ◽

Chromosome Ii

A circular minichromosome carrying functional centromere sequences (cen2) from Schizosaccharomyces pombe chromosome II behaves as a stable, independent genetic linkage group in S. pombe. The cen2 region was found to be organized into four large tandemly repeated sequence units which span over 80 kilobase pairs (kb) of untranscribed DNA. Two of these units occurred in a 31-kb inverted repeat that flanked a 7-kb central core of nonhomology. The inverted repeat region had centromere function, but neither the central core alone nor one arm of the inverted repeat was functional. Deletion of a portion of the repeated sequences that flank the central core had no effect on mitotic segregation functions or on meiotic segregation of a minichromosome to two of the four haploid progeny, but drastically impaired centromere-mediated maintenance of sister chromatid attachment in meiosis I. This requirement for centromere-specific repeated sequences could not be satisfied by introduction of random DNA sequences. These observations suggest a function for the heterochromatic repeated DNA sequences found in the centromere regions of higher eucaryotes.

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Isolation and Chromosomal Localization of Highly Repeated DNA Sequences in Drosophila melanogaster

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.68.6.1125 ◽

1971 ◽

Vol 68 (6) ◽

pp. 1125-1129 ◽

Cited By ~ 48

Author(s):

M. Botchan ◽

R. Kram ◽

C. W. Schmid ◽

J. E. Hearst

Keyword(s):

Drosophila Melanogaster ◽

Dna Sequences ◽

Chromosomal Localization ◽

Repeated Dna ◽

Repeated Dna Sequences ◽

Highly Repeated Dna

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EVIDENCE FOR A SET OF CLOSELY LINKED AUTOSOMAL GENES THAT INTERACT WITH SEX-CHROMOSOME HETEROCHROMATIN IN DROSOPHILA MELANOGASTER

Genetics ◽

10.1093/genetics/86.3.567 ◽

1977 ◽

Vol 86 (3) ◽

pp. 567-582

Author(s):

L Sandler

Keyword(s):

Drosophila Melanogaster ◽

Salivary Gland ◽

Y Chromosome ◽

Maternal Effect ◽

Sex Chromosome ◽

Salivary Gland Chromosome ◽

Chromosome 2 ◽

Chromosome Map ◽

Heterochromatic Segment ◽

Special Region

ABSTRACT It is proposed that there exists a special region in the euchromatin of the left arm of chromosome 2 (contained within sections 31-32 of the standard salivary gland chromosome map) that is defined by a set of genes, each one of which interacts with a specific sex-chromosome heterochromatic segment. The evidence for the existence of this region is, first, the exhibition, mapping, and analysis of five different maternal-effect, embryonic semi-lethals located in region 31-32. Secondly, in each case the consequence of the maternal effect is markedly influenced by the amount of X- or Y-chromosome heterochromatin carried by the progeny of mutant mothers. The nature of this interaction and possible reasons for the existence of the cluster of autosomal genes are discussed

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A sister-strand exchange mechanism for recA-independent deletion of repeated DNA sequences in Escherichia coli.

Genetics ◽

10.1093/genetics/135.3.631 ◽

1993 ◽

Vol 135 (3) ◽

pp. 631-642 ◽

Cited By ~ 11

Author(s):

S T Lovett ◽

P T Drapkin ◽

V A Sutera ◽

T J Gluckman-Peskind

Keyword(s):

Escherichia Coli ◽

Dna Sequences ◽

Repeated Sequences ◽

Repeated Dna ◽

Repeated Dna Sequences ◽

E Coli ◽

Deletion Formation ◽

Dna Strands

Abstract In the genomes of many organisms, deletions arise between tandemly repeated DNA sequences of lengths ranging from several kilobases to only a few nucleotides. Using a plasmid-based assay for deletion of a 787-bp tandem repeat, we have found that a recA-independent mechanism contributes substantially to the deletion process of even this large region of homology. No Escherichia coli recombination gene tested, including recA, had greater than a fivefold effect on deletion rates. The recA-independence of deletion formation is also observed with constructions present on the chromosome. RecA promotes synapsis and transfer of homologous DNA strands in vitro and is indispensable for intermolecular recombination events in vivo measured after conjugation. Because deletion formation in E. coli shows little or no dependence on recA, it has been assumed that homologous recombination contributes little to the deletion process. However, we have found recA-independent deletion products suggestive of reciprocal crossovers when branch migration in the cell is inhibited by a ruvA mutation. We propose a model for recA-independent crossovers between replicating sister strands, which can also explain deletion or amplification of repeated sequences. We suggest that this process may be initiated as post-replicational DNA repair; subsequent strand misalignment at repeated sequences leads to genetic rearrangements.

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THE EVOLUTION OF RESTRICTED RECOMBINATION AND THE ACCUMULATION OF REPEATED DNA SEQUENCES

Genetics ◽

10.1093/genetics/112.4.947 ◽

1986 ◽

Vol 112 (4) ◽

pp. 947-962 ◽

Cited By ~ 1

Author(s):

Brian Charlesworth ◽

Charles H Langley ◽

Wolfgang Stephan

Keyword(s):

Dna Sequences ◽

Single Copy ◽

Repeated Sequences ◽

Stabilizing Selection ◽

Crossing Over ◽

Repeated Dna ◽

Repeated Dna Sequences ◽

Unequal Exchange ◽

Single Copy Sequence ◽

Speed Up

ABSTRACT We suggest hypotheses to account for two major features of chromosomal organization in higher eukaryotes. The first of these is the general restriction of crossing over in the neighborhood of centromeres and telomeres. We propose that this is a consequence of selection for reduced rates of unequal exchange between repeated DNA sequences for which the copy number is subject to stabilizing selection: microtubule binding sites, in the case of centromeres, and the short repeated sequences needed for terminal replication of a linear DNA molecule, in the case of telomeres. An association between proximal crossing over and nondisjunction would also favor the restriction of crossing over near the centromere. The second feature is the association between highly repeated DNA sequences of no obvious functional significance and regions of restricted crossing over. We show that highly repeated sequences are likely to persist longest (over evolutionary time) when crossing over is infrequent. This is because unequal exchange among repeated sequences generates single copy sequences, and a population that becomes fixed for a single copy sequence by drift remains in this state indefinitely (in the absence of gene amplification processes). Increased rates of exchange thus speed up the process of stochastic loss of repeated sequences.

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Molecular characterization and chromosome location of repeated DNA sequences in Hordeum species and in the amphiploid tritordeum (×Tritordeum Ascherson et Graebner)

Genome ◽

10.1139/g95-112 ◽

1995 ◽

Vol 38 (5) ◽

pp. 850-857 ◽

Cited By ~ 5

Author(s):

Esther Ferrer ◽

Yolanda Loarce ◽

Gregorio Hueros

Keyword(s):

In Situ Hybridization ◽

Dna Sequences ◽

Diploid Species ◽

Repeated Sequences ◽

Hordeum Chilense ◽

Repeated Dna ◽

Repeated Dna Sequences ◽

In Situ Experiments ◽

Basic Genome

Genomic DNA from 19 species and subspecies representing the four basic genomes (H, I, X, and Y) of Hordeum was restricted with HaeIII and hybridized with two repeated DNA sequences of Hordeum chilense. The potential use of repeated sequences in ascertaining genomic affinities within the genus Hordeum was studied by comparing restriction fragment patterns. The study demonstrated the following: (i) species that shared a basic genome showed more similar hybridization fragment patterns than species with different genomes, whether with pHchl or pHch3; (ii) hybridization with pHchl revealed the presence of certain fragments limited to the species with a H genome; and (iii) the alloploid nature of species like H. jubatum was confirmed. The chromosomal distribution of the two repeated sequences was studied in species representing each basic genome and in the amphiploid tritordeum using fluorescent in situ hybridization. No interspecific differences were found between the diploid species. In situ experiments indicated the alloploid nature of H. depressum. Both sequences allow H. chilense chromatin to be distinguished from wheat chromosomes in tritordeum.Key words: repeated DNA sequences; in situ hybridization, Hordeum, tritordeum.

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