Differentiate between repetitive dna and satellite dna

Repetitive DNA A repetitive DNA sequence bound by a group of protective proteins (shelterins) that protect the ends of all linear chromosomes against DNA loss and faulty recombination. From: Reference Module in Biomedical Sciences, 2014 Related terms: • Telomere • Neoplasm • Microsatellite Instability • Telomerase • Tissues • Methylation • DNA Sequence • DNA Methylation R.M. Twyman, in Encyclopedia of Neuroscience, 2009 Repetitive DNA Repetitive DNA sequences (both endogenous sequences and transgenes) are often subject to transcriptional silencing because they act as nucleation centers for heterochromatin formation. This occurs both at tandem repeats, such as those found in the centromeric region of chromosomes, and at dispersed repeats, such as transposable elements and integrated transgenes. In some cases, repeated sequences may trigger heterochromatin formation because they attract sequence-specific DNA-binding proteins which are in turn recognized by HDACs or DNMTs, or proteins such as HP1. In yeast, for example, repetitive DNA sequences found at the telomeres are recognized by the DNA-binding protein Rap1, which interacts with components of the heterochromatin machinery and ensures localization at the nuclear periphery. Since mammalian transposable elements and transgenes are diverse in their sequences, it is unlikely that a sequence-specific mechanism is involved and suggests that the cell possesses some kind of mechanism for sensing repeated DNA sequences and target...

Satellite DNA comprises long arrays of tandem DNA repeats with moderate to long length, that account for the majority of heterochromatic sequences of the human genome, organizing centromeric, paracentromeric, and acrocentric regions of eukaryotic chromosomes, as well as the human Y chromosome. Tandemly repeated DNA is also found disperse in the human genome with shorter repeat motifs constituting mini- and microsatellite DNA, which are inherited in a Mendelian pattern. Their frequent length polymorphisms make them the most commonly employed DNA markers in forensic identification of individuals. In addition, microsatellite instability is a marker for detection of DNA repair deficiency in cancer. Expansions of the transcribed microsatellite repeat number in specific loci associate with rare chromosomal fragile sites and distinct neurological diseases, some of which show clinical anticipation according to further intergeneration repeat expansions. Clarification of molecular models of the genetic pathophysiology of these diseases has considerably advanced owing to the characterization of translation patterns of triplet repeat-containing mRNA and intracellular accumulation of these transcripts or unfolded proteins. The most recent technologies of massively parallel DNA sequencing generating longer reads more amenable to accurate mapping of repeats to specific chromosomal loci have been improving our understanding of the organization of tandemly repetitive DNA in the human genom...

• Article • • 17 August 2022 Identification and characterization of a new family of long satellite DNA, specific of true toads (Anura, Amphibia, Bufonidae) • ORCID: orcid.org/0000-0003-1440-8800 • ORCID: orcid.org/0000-0002-7363-3939 • ORCID: orcid.org/0000-0003-4888-8371 • ORCID: orcid.org/0000-0002-6773-5066 • ORCID: orcid.org/0000-0002-4831-8822 • … • ORCID: orcid.org/0000-0003-3256-8840 Show authors Scientific Reports volume 12, Article number: 13960 ( 2022) Amphibians have some of the most variable genome sizes among vertebrates. Genome size variation has been attributed to repetitive and noncoding DNA, including satellite repeats, transposable elements, introns, and nuclear insertions of viral and organelle DNA. In vertebrates, satellite DNAs have been widely described in mammals, but few molecular studies have been carried out in amphibians. Here, we provide a detailed characterization of a new family of satellite DNA, present in all 15 examined species of the family Bufonidae. Southern-blot analysis and PCR reveal that this satellite is formed by monomers of 807 bp, is organized in tandem arrays, and has an AT-content of 57.4%. Phylogenetic analyses show that most clades exhibit species-specific variances, indicating that this satellite DNA has evolved by concerted evolution. The homogenization/fixation process is heterogeneous in Bufonidae, where the genera Bufo and Bufotes do not show species-specific differences, while populations from Rhinella marina exhibit po...