Strand-specific fluorescent in situ hybridization reveals orientation of satellite DNA sequences

1993 ◽  
Vol 66 (2) ◽  
pp. 143
1991 ◽  
Vol 40 (1) ◽  
pp. 117-120 ◽  
Author(s):  
Avirachan T. Tharapel ◽  
Mazin B. Qumsiyeh ◽  
Paula R. Martens ◽  
Sugandhi A. Tharapel ◽  
James D. Dalton ◽  
...  

Genome ◽  
1996 ◽  
Vol 39 (2) ◽  
pp. 243-248 ◽  
Author(s):  
Thomas Schmidt ◽  
Jörg Kudla

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.


1992 ◽  
Vol 62 (2) ◽  
pp. 140-143 ◽  
Author(s):  
Hitoshi Nakagawa ◽  
Johji Inazawa ◽  
Shinichi Misawa ◽  
Shinji Tanaka ◽  
Teruyuki Takashima ◽  
...  

Genome ◽  
2004 ◽  
Vol 47 (4) ◽  
pp. 742-746 ◽  
Author(s):  
Francesco Fontana ◽  
Ronald M Bruch ◽  
Fred P Binkowski ◽  
Massimo Lanfredi ◽  
Milvia Chicca ◽  
...  

A karyotype analysis using several staining techniques was carried out on the North American lake sturgeon, Acipenser fulvescens. The chromosome number was found to be 2n = 262 ± 6. A representative karyotype of 264 chromosomes was composed of 134 meta- and submetacentrics, 70 telo- and acrocentrics, and 60 microchromosomes. The constitutive heterochromatin, revealed by C banding, was localized in various positions on several chromosomes, including microchromosomes. The signals of fluorescent in situ hybridization (FISH) with a HindIII satellite DNA probe were visible as centromeric heterochromatin blocks on 48 chromosomes. The telomeric repeat (TTAGGG)n detected by FISH was localized at both ends of all chromosomes and two chromosomes were entirely marked. Fluorescent staining with GC-specific chromomycin A3 showed recognizable fluorescent regions, whereas a more uniform base composition was revealed by the AT-specific 4',6-diamidino-2-phenylindole (DAPI). After silver staining, the active nucleolar organizer regions (NORs) were detected on 12 chromosomes. FISH with the 5S probe showed four signals on four small chromosomes. Our data suggest that A. fulvescens is a tetraploid species.Key words: karyotype, C banding, telomeric sequence, fluorochrome staining, satellite DNA, 5S rDNA.


Genome ◽  
2001 ◽  
Vol 44 (4) ◽  
pp. 640-643 ◽  
Author(s):  
N Cuñado ◽  
E Sánchez-Morán ◽  
J Barrios ◽  
J L Santos

Some Alliaceae species have no tandemly repeated TTTAGGG sequences. Instead, at the very end of their chromosomes, there are highly repetitive satellite and (or) rDNA sequences. These sequences apparently replace the canonical plant telomeric sequences in these species. A method of preparing two-dimensional surface spreads of plant synaptonemal complexes (SCs), combined with fluorescent in situ hybridization, has revealed that telomeric chromatin is tightly condensed at the ends of SCs in plants and animals. Using this method, we have tested the organization and location of those sequences postulated to cap the chromosomes in two species of the genus Allium: A. cepa and A. altaicum. We have also extended this study to other putative telomere candidates, such as LTR (long terminal repeat) and non-LTR retrotransposons. None of the DNA sequences analyzed showed the characteristic telomeric organization at pachytene.Key words: fluorescent in situ hybridization, meiosis, repetitive DNA, Allium, synaptonemal complex.


Genome ◽  
1996 ◽  
Vol 39 (6) ◽  
pp. 1210-1213
Author(s):  
José Luis Fernández ◽  
Carmen López-Fernández ◽  
Jaime Gosálvez ◽  
Vicente Goyanes

Fluorescent in situ hybridization of alphoid and classical satellite III DNA sequences was performed on fixed chromosomes from human lymphocytes that were previously digested in situ with exonuclease III to produce single-stranded DNA motifs. Digital image analysis showed that while labeled alphoid satellite DNAs produced signals of similar strength to thermally denatured chromosomes, those of classical satellite III DNAs of chromosomes 9 and Yq were around 50% weaker. This result shows a differential sensitivity of these satellite DNA regions to in situ exonuclease III digestion and suggests structural differences in the higher-order organization of both subchromosomal constitutive heterochromatic regions. Key words : alphoid sequences, classical satellite, exonuclease III, FISH, human cytogenetics, satellite DNA.


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