PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 728672

[Structure of interphase chromosomes].

M Noll
View original source ↗Export metadata ↓

Abstract

The chromosomes are based on a structural unit, the nucleosome. It consists of a protein care and about 200 base pairs of DNA arranged on its outside in a regular way, probably as a spiral. The protein care is a histone octamer containing two copies each of the four main types of histones, H2A, H2B, H3, and H4. The shape of the nucleosome ressembles a short wedge shaped cylinder of 110 A x 110 A x 60 A. The nucleosomes are closely spaced and linked by the continuous DNA. Since the fifth histone, H1, stabilizes the interaction of adjacent nucleosomes, it is considered to be involved in the formation of higher structural orders in the chromosomes.

Explore related subjects

ChromosomesDNAHistonesHumansInterphaseMolecular WeightEnglish AbstractJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M Noll. 1978. [Structure of interphase chromosomes].. https://pubmed.ncbi.nlm.nih.gov/728672/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2026

Chromosome-level genome assembly of a cosmopolitan marine harmful algal bloom diatom species Chaetoceros socialis (Chaetocerotaceae).

Chaetoceros socialis is a cosmopolitan diatom species that is crucial for maintaining marine ecosystem structure and driving elemental cycles. C. socialis can form harmful algal blooms (HABs) that may cause a negative impact on the marine ecosystems. Whole-genome information for C. socialis is still unavailable, which may hinder more targeted studies on its ecological adaptive responses and evolutionary drivers. To address this gap, we employed cutting-edge genomic technologies including PacBio single-molecule real-time (SMRT) sequencing and high-throughput chromatin conformation capture (Hi-C) to achieve the first chromosome-level genome assembly of C. socialis. The assembled genome is 60.22 Mb in size with a scaffold N50 of 7.81 Mb and has been anchored to eight pseudochromosomes. A total of 13,378 protein-coding genes were predicted, of which 12,069 (90.22%) were functionally annotated. This high-quality genomic resource provides a fundamental data platform for systematically elucidating the ecological adaptation mechanisms of C. socialis.

Chromosomes↗
PubMed2025

Chromosome-level genome assembly of the Vermilion Snapper (Rhomboplites aurorubens).

Vermilion Snapper (Rhomboplites aurorubens, Lutjanidae) inhabits deep waters (20-300 m) from North America to Brazil and supports significant commercial and recreational fisheries. Despite its economic importance, the understanding of its basic biology remains limited. Classified as Vulnerable on the Red List due to overfishing, populations have declined by over 30% in recent generations. We assembled and annotated the first chromosome-scale genome of this species by combining PacBio long reads, Illumina short reads, and Hi-C data. The resulting assembly is 987.5 Mbp, with a scaffold N50 size of 41.3 Mbp, and includes 135 contigs clustered and ordered onto 24 chromosomes with 34,496 predicted genes. The high-quality assembly and annotation contained about 98% complete and single-copy BUSCO genes. It is the most complete, chromosome-level genome assembly of an Atlantic snapper to date. The genome assembly and supporting data are valuable tools for ecological and comparative genomics studies of snappers and other valuable commercial species within the family.

Chromosomes↗
PubMed2006

A role for TFIIIC transcription factor complex in genome organization.

Eukaryotic genome complexity necessitates boundary and insulator elements to partition genomic content into distinct domains. We show that inverted repeat (IR) boundary elements flanking the fission yeast mating-type heterochromatin domain contain B-box sequences, which prevent heterochromatin from spreading into neighboring euchromatic regions by recruiting transcription factor TFIIIC complex without RNA polymerase III (Pol III). Genome-wide analysis reveals TFIIIC with Pol III at all tRNA genes, many of which cluster at pericentromeric heterochromatin domain boundaries. However, a single tRNA(phe) gene with modest TFIIIC enrichment is insufficient to serve as boundary and requires RNAi-associated element to restrain heterochromatin spreading. Remarkably, we found TFIIIC localization without Pol III at many sites located between divergent promoters. These sites appear to act as chromosome-organizing clamps by tethering distant loci to the nuclear periphery, at which TFIIIC is concentrated into several distinct bodies. Our analyses uncover a general genome organization mechanism involving conserved TFIIIC complex.

Chromosomes↗