Search results for "Transposable element"
showing 7 items of 107 documents
Extensive nuclear gyration and pervasive non-genic transcription during primordial germ cell development in zebrafish.
2020
ABSTRACT Primordial germ cells (PGCs) are the precursors of germ cells, which migrate to the genital ridge during early development. Relatively little is known about PGCs after their migration. We studied this post-migratory stage using microscopy and sequencing techniques, and found that many PGC-specific genes, including genes known to induce PGC fate in the mouse, are only activated several days after migration. At this same time point, PGC nuclei become extremely gyrated, displaying general broad opening of chromatin and high levels of intergenic transcription. This is accompanied by changes in nuage morphology, expression of large loci (PGC-expressed non-coding RNA loci, PERLs) that ar…
Mobile genetic element proliferation and gene inactivation impact over the genome structure and metabolic capabilities of Sodalis glossinidius, the s…
2010
Abstract Background Genome reduction is a common evolutionary process in symbiotic and pathogenic bacteria. This process has been extensively characterized in bacterial endosymbionts of insects, where primary mutualistic bacteria represent the most extreme cases of genome reduction consequence of a massive process of gene inactivation and loss during their evolution from free-living ancestors. Sodalis glossinidius, the secondary endosymbiont of tsetse flies, contains one of the few complete genomes of bacteria at the very beginning of the symbiotic association, allowing to evaluate the relative impact of mobile genetic element proliferation and gene inactivation over the structure and funct…
Patterns and rates of nucleotide substitution, insertion and deletion in the endosymbiont of antsBlochmannia floridanus
2009
Genome reduction is a general process that has been studied in numerous symbiotic bacteria associated with insects. We investigated the last stages of genome degradation in Blochmannia floridanus, a mutualistic bacterial endosymbiont of the ant Camponotus floridanus. We determined the tempo (rates of insertion and deletion) and mode (size and number of insertion-deletion events) of the process in the last 200,000 years by analysing a total of 16 intergenic regions in several strains of this endosymbiont from different ant populations. We provide the first calculation of the reduction rate for noncoding DNA in this endosymbiont (2.2 x 10(-8) lost nucleotides/site/year) and compare it with th…
Retrotranspozonu struktūra parastās priedes (Pinus sylvestris L.) genomā un to ekspresija
2014
ANOTĀCIJA Promocijas darbs izstrādāts Latvijas Valsts mežzinātnes institūtā „Silava”. Pētījuma mērķis bija identificēt aktīvos retrotranspozonus parastās priedes (Pinus sylvestris L.) genomā un raksturot to transkripcijas līmeni dažādu stresa veidu ietekmē kontrolētos apstākļos. Pētījumā izmantoti nespecifiskie retrotranspozonu marķieri balstīti uz augsti konservatīvām tRNS piesaistes vietām. Viena klona priežu rametus pakļāva dabā izplatītam karstuma stresam, kukaiņu invāzijai (priežu hermess (Pineus pini L.), kā arī mākslīgi izraisītai augu hormonu (abscīzskābes un salicilskābes) ietekmei. Darba rezultātā identificēti pārsvarā I klases mobīlo elementu pārstāvji, kā arī tos saturošie himēr…
Computational prediction of the Helitron-N2 (HeN2) transposable element in the strim1 locus of the Paracentrotus lividus genome
2011
Transposons constitute a significant component of the eukaryotic genome. Among others, Helitrons represent a novel major class of eukaryotic transposons, and are fundamentally different from classical ones in terms of their structure and mechanism of transposition [1]. In particular, Helitrons constitute ~1% of the sea urchin genome [2]. By a in silico approach focused on the genome of the Mediterranean sea urchin Paracentrotus lividus, we have predicted regions of high sequence identity to a Helitron-N2 (HeN2) element in the strim1 locus. Of interest, HeN2 sequences lies within the 5’ non coding region of the strim1a and strim1b genes, spanning from -105 to -2255 (the start codon ATG of st…
Double copies of blaKPC-3::Tn4401a on an IncX3 plasmid in Klebsiella pneumoniae successful clone ST512 from Italy
2015
ABSTRACT A carbapenem-resistant sequence type 512 (ST512) Klebsiella pneumoniae carbapenemase 3 (KPC-3)-producing K. pneumoniae strain showing a novel variant plasmid content was isolated in Palermo, Italy, in 2014. ST512 is a worldwide successful clone associated with the spread of bla KPC genes located on the IncFIIk pKpQIL plasmid. In our ST512 strain, the bla KPC-3 gene was unusually located on an IncX3 plasmid, whose complete sequence was determined. Two copies of bla KPC-3 ::Tn 4401a caused by intramolecular transposition events were detected in the plasmid.
The prolyl-isomerase PIN1 is essential for nuclear Lamin-B structure and function and protects heterochromatin under mechanical stress.
2021
Summary: Chromatin organization plays a crucial role in tissue homeostasis. Heterochromatin relaxation and consequent unscheduled mobilization of transposable elements (TEs) are emerging as key contributors of aging and aging-related pathologies, including Alzheimer’s disease (AD) and cancer. However, the mechanisms governing heterochromatin maintenance or its relaxation in pathological conditions remain poorly understood. Here we show that PIN1, the only phosphorylation-specific cis/trans prolyl isomerase, whose loss is associated with premature aging and AD, is essential to preserve heterochromatin. We demonstrate that this PIN1 function is conserved from Drosophila to humans and prevents…