Satellite sequences present in the centromeric and pericentric regions of chromosomes represent useful source of information. Changes in satellite DNA composition may coincide with the speciation and serve as valuable markers of phylogenetic relationships. Here, we examined satellite DNA clones isolated by laser microdissection of centromeric regions of 38 bovid species and categorized them into three types. Sat I sequences from members of Bovini/Tragelaphini/Boselaphini are similar to the well-documented 1.715 sat I DNA family. Sat I DNA from Caprini/Alcelaphini/Hippotragini/Reduncini/Aepycerotini/Cephalophini/Antilopini/Neotragini/Oreotragini form the second group homologous to the common 1.714 sat I DNA. The analysis of sat II DNAs isolated in our study confirmed conservativeness of these sequences within Bovidae. Newly described centromeric clones from Madoqua kirkii and Strepsiceros strepsiceros were similar in length and repetitive tandem arrangement but showed no similarity to any other satellite DNA in the GenBank database. Phylogenetic analysis of sat I sequences isolated in our study from 38 bovid species enabled the description of relationships at the subfamily and tribal levels. The maximum likelihood and Bayesian inference analyses showed a basal position of sequences from Oreotragini in the subfamily Antilopinae. According to the Bayesian inference analysis based on the indels in a partitioned mixed model, Antilopinae satellite DNA split into two groups with those from Neotragini as a basal tribe, followed by a stepwise, successive branching of Cephalophini, Aepycerotini and Antilopini sequences. In the second group, Reduncini sequences were basal followed by Caprini, Alcelaphini and Hippotragini.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/s10577-014-9401-4 | DOI Listing |
The eukaryotic genome is packaged into chromatin, which is composed of a nucleosomal filament that coils up to form more compact structures. Chromatin exists in two main forms: euchromatin, which is relatively decondensed and enriched in transcriptionally active genes, and heterochromatin, which is condensed and transcriptionally repressed . It is widely accepted that chromatin architecture modulates DNA accessibility, restricting the access of sequence-specific, gene-regulatory, transcription factors to the genome.
View Article and Find Full Text PDFUnlabelled: is one of the three most frequently mutated genes in age-related clonal hematopoiesis (CH), alongside and . CH can progress to myeloid malignancies including chronic monomyelocytic leukemia (CMML), and is also strongly associated with inflammatory cardiovascular disease and all-cause mortality in humans. DNMT3A and TET2 regulate DNA methylation and demethylation pathways respectively, and loss-of-function mutations in these genes reduce DNA methylation in heterochromatin, allowing de-repression of silenced elements in heterochromatin.
View Article and Find Full Text PDFSci Total Environ
January 2025
Naturalis Biodiversity Center, Darwinweg 2, 2333 CR Leiden, the Netherlands; IBED, University of Amsterdam, Sciencepark 904, 1098 XH Amsterdam, the Netherlands.
Commun Biol
January 2025
Faculty of Life and Environmental Sciences, University of Yamanashi, Yamanashi, Japan.
Abnormal chromosome segregation (ACS) in preimplantation embryos causes miscarriages. For a normal pregnancy, it is necessary to reduce ACS occurrences in embryos. However, the causes of such abnormalities are unclear because no method to extract the segregated chromosomes from the blastomeres for detailed analysis.
View Article and Find Full Text PDFNat Commun
January 2025
Laboratory of Structural Biochemistry, Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany.
Many bacteriophages modulate host transcription to favor expression of their own genomes. Phage satellite P4 polarity suppression protein, Psu, a building block of the viral capsid, inhibits hexameric transcription termination factor, ρ, by presently unknown mechanisms. Our cryogenic electron microscopy structures of ρ-Psu complexes show that Psu dimers clamp two inactive, open ρ rings and promote their expansion to higher-oligomeric states.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!