The premature aging disease Hutchinson-Gilford Progeria Syndrome (HGPS) is caused by a mutant lamin A (LADelta50). Nuclei in cells expressing LADelta50 are abnormally shaped and display a loss of heterochromatin. To determine the mechanisms responsible for the loss of heterochromatin, epigenetic marks regulating either facultative or constitutive heterochromatin were examined. In cells from a f...

Constitutive heterochromatin is a compact, transcriptionally inert structure formed in gene-poor and repeat- and transposon-rich regions. In Arabidopsis, constitutive heterochromatin is characterized by hypermethylated DNA and histone H3 dimethylated at lysine (K) 9 (H3K9me2) together with depletion of histone H3 dimethylated at lysine 4 (H3K4me2). Here, we describe loci with intermediate prope...

introduction: heterochromatin consists of dna sequences that are not transcribed, and are repeated in short tandem at heterochromatic regions of chromosomes 1, 9, 16 as well as the distal part of long arm of chromosome y. slightly large tandem repeats at the centromeres of human chromosomes are also considered as heterochromatin regions. the main aim of the present study is to evaluate the hete...

Similarities and differences become evident from comparisons of centromeric and non-centromeric banding patterns in plant and animal chromosomes. Similar to C and G-banding in animals (at least most of the reptiles, birds and mammals), centromeric and nucleolus-organizing region bands as well as interstitially and/or terminally located non-centromeric bands may occur in plants, depending on the...

A four-generation transmission of 1qh+ chromosome was ascertained by routine chromosome analysis of a mildly dysmorphic and retarded 61/2-year-old female. Concordance between synophrys and the 1qh+ marker was the only consistent phenotypic relationship. The variant chromosome did not appear uncoiled, and Giemsa centromeric staining (C-bands) revealed an increased width of the heterochromatin co...

The C-banding karyotype of the jerboas Allactaga tetradactyla, Jaculus jaculus jaculus, and Jaculus orientalis was described and interspecific relationships were discussed. Despite the conservation of a relatively small amount of C-heterochromatin located at the centromeric region of some chromosomes in all karyotypes, a striking loss of C-heterochromatin was clearly observed in J. orientalis. ...

Although the underlying mechanism for these chromosomal alterations is unclear, it is possible that chromosomes with large constitutive heterochromatin bands such as chromosome 1 may be at risk of centromeric instability and be predisposed to centromeric fusion with other chromosomes. This possibility is supported by observations that unbalanced chromosome rearrangements frequently involve the ...

Tityus trivittatus Kraepelin, 1898 is the most medically important scorpion species of Argentina, and parthenogenetic populations are present in the major cities of this country. We performed a detailed cytogenetic analysis of specimens of three synanthropic parthenogenetic populations, all distant about 900 km from each other, using Ag-NOR, C-banding, DAPI/CMA3 staining and FISH with autologou...

The use of in situ restriction endonuclease (RE) (which cleaves DNA at specific sequences) digestion has proven to be a useful technique in improving the dissection of constitutive heterochromatin (CH), and in the understanding of the CH evolution in different genomes. In the present work we describe in detail the CH of the three Rodentia species, Cricetus cricetus, Peromyscus eremicus (family ...