Oculo-auriculovertebral dysplasia (Goldenhar) is a congenital syndrome. Its phenotype differs from craniofacial anomalies to cardiac, vertebral or central nervous system defects. This syndrome is rare and its etiology is not apparent yet. Pericentric inversion of chromosome 9 is one of the most common structural balanced chromosomal aberrations with its incidences 15% to 25%. Herein we present ...

Maintenance of proper chromatin states and genomic stability is vital for normal development and health across a range of organisms. Here, we report on the role of KLLN in maintenance of pericentric H3K9 trimethylation (H3K9me3) and genomic stability. Germline hypermethylation of KLLN, a gene uncovered well after the human genome project, has been linked to Cowden cancer-predisposition syndrome...

Received 4 April 1972. * Cytogenetics Laboratory, Genetics Committee of the University of Iceland, Department of Pathology, Reykjavik, Iceland. t Paediatric Department, University Hospital Iceland; Home for the Mentally Retarded, K6pavogur; Paediatric Department, St Joseph's Hospital, Reykiavik, Iceland. t John F. Kennedy Instituttet, GI. Landevej 7-9, Copenhagen, Denmark. ** Faculty of Medicin...

BACKGROUND Histone H3 lysine 9 (H3-K9) methylation and DNA methylation are characteristic hallmarks of mammalian heterochromatin. H3-K9 methylation was recently shown to be a prerequisite for DNA methylation in Neurospora crassa and Arabidopsis thaliana. Currently, it is unknown whether a similar dependence exists in mammalian organisms. RESULTS Here, we demonstrate a physical and functional ...

In mammalian heterochromatin, cytosine bases of CpG dinucleotides are symmetrically modified by methylation. Patterns of CpG methylation are maintained by the action of Dnmt1, the mammalian maintenance cytosine methyltransferase enzyme. We genetically manipulated the levels of CpG methylation and found that extensive chromatin alterations occur in pericentric heterochromatin. Homozygous mutatio...

Many hypotheses have been put forth to explain the origin and spread of inversions, and their significance for speciation. Several recent genic models have proposed that inversions promote speciation with gene flow due to the adaptive significance of the genes contained within them and because of the effects inversions have on suppressing recombination. However, the consequences of inversions f...

We generated mutant alleles of Drosophila melanogaster in which expression of the linker histone H1 can be down-regulated over a wide range by RNAi. When the H1 protein level is reduced to approximately 20% of the level in wild-type larvae, lethality occurs in the late larval - pupal stages of development. Here we show that H1 has an important function in gene regulation within or near heteroch...

Heterochromatin preferentially assembles at repetitive DNA elements, playing roles in transcriptional silencing, recombination suppression, and chromosome segregation. The RNAi machinery is required for heterochromatin assembly in a diverse range of organisms. In fission yeast, RNA splicing factors are also required for pericentric heterochromatin assembly, and a prevailing model is that splici...

Pericentric heterochromatin transcription has been implicated in Schizosaccharomyces pombe heterochromatin assembly and maintenance. However, in mammalian systems, evidence for such transcription is inconsistent. We identify two populations of RNA polymerase II-dependent mouse gamma satellite repeat sequence-derived transcripts from pericentric heterochromatin that accumulate at different times...