Month: September 2022

PROTECTIONS AGAINST TEs. “Because excessive TE activity can damage exons, many organisms have acquired mechanisms to inhibit their activity. Bacteria may undergo high rates of gene deletion as part of a mechanism to remove TEs and viruses from their genomes, while eukaryotic organisms typically use RNA interference to inhibit TE activity. Nevertheless, some TEs generate large families often associated with speciation events.” (TE = transposable elements, jumping genes). https://en.m.wikipedia.org/wiki/Transposable_element View in LinkedIn

JUMPING GENE FOSSILS. “Evolution often deactivates DNA transposons, leaving them as introns (inactive gene sequences). In vertebrate animal cells, nearly all 100,000+ DNA transposons per genome have genes that encode inactive transposase polypeptides. In humans, all Tc1-like transposons are inactive.” https://en.m.wikipedia.org/wiki/Transposable_element View in LinkedIn

DNA REPEATS. “Interspersed repeats within genomes are created by transposition events accumulating over evolutionary time. Because interspersed repeats block gene conversion, they protect novel gene sequences from being overwritten by similar gene sequences and thereby facilitate the development of new genes. TEs may also have been co-opted by the vertebrate immune system as a means of producing antibody diversity. The V(D)J recombination system operates by a mechanism similar to that of some TEs.” (TE = transposable elements, jumping genes). https://en.m.wikipedia.org/wiki/Transposable_element View in LinkedIn

SLOPPY CUTTING. “Transposons do not always excise their elements precisely, sometimes removing the adjacent base pairs; this phenomenon is called exon shuffling. Shuffling two unrelated exons can create a novel gene product or, more likely, an intron.” https://en.m.wikipedia.org/wiki/Transposable_element View in LinkedIn

PROMISCUOUS GENE SHUFFLING. “TEs can contain many types of genes, including those conferring antibiotic resistance and ability to transpose to conjugative plasmids. Some TEs also contain integrons, genetic elements that can capture and express genes from other sources. These contain integrase, which can integrate gene cassettes. There are over 40 antibiotic resistance genes identified on cassettes, as well as virulence genes.” (TE = transposable elements, jumping genes). https://en.m.wikipedia.org/wiki/Transposable_element View in LinkedIn

MASSIVE VIRAL FOOTPRINT. “TEs constitute more than half of the DNA in many higher eukaryotes. We know, too, that the fingerprints of TEs and transposition are everywhere in their genomes, from the coarsest features of genomic landscapes and how they change through real and evolutionary time to the finest details of gene structure and regulation.” (TE = transposable elements, jumping genes). http://science.sciencemag.org/content/338/6108/758 View in LinkedIn

VIRAL FOSSILS. “Much of the human genome is repetitive sequence derived from transposable elements. These include copy-and-paste retrotransposons and cut-and-paste DNA transposons. Only retrotransposons are active as undomesticated mobile DNAs in humans.” https://lnkd.in/df3hrCx View in LinkedIn

AUTONOMOUS JUMPING GENES. “DNA transposons represent a specific group of TEs, and they can be classified as either “autonomous” or “non-autonomous” elements. Autonomous transposons can transpose by themselves, while non-autonomous elements require enzymes encoded in trans by autonomous elements to be mobile.” (TE = transposable elements, jumping genes). https://lnkd.in/dxjKEGX View in LinkedIn

MASSIVE ROLE IN EVOLUTION. “MITEs are often flanked by terminal inverted repeats (TIRs) and produce a short target site duplication (TSD) upon integration. As a group, MITEs form several superfamilies classified according to sequence similarity between their TIRs or TSD and those of autonomous partners. It has been shown that MITEs play important roles in eukaryotic evolution, including an increase in genome size, formation of new genes, and the regulation of gene expression.” (MITEs = miniature inverted-repeat transposable elements); (TIR = terminal inverted repeats); (TSD = target site duplication). https://mobilednajournal.biomedcentral.com/articles/10.1186/s13100-018-0125-4 View in LinkedIn

SHAPING EVOLUTION. “Our discovery highlights that TEs contribute to shape genome evolution of pandoraviruses. We concluded that as for cellular organisms, TEs are part of the pandoraviruses’ diverse mobilome.” (TE = transposable elements, jumping genes). https://mobilednajournal.biomedcentral.com/articles/10.1186/s13100-018-0125-4 View in LinkedIn