The TATA-box binding protein (TBP) is the sole transcription factor common in the initiation complexes of the three major eukaryotic RNA Polymerases (Pol I, II and III). Although TBP is central to transcription by the three RNA Pols in various species, the emergence of TBP paralogs throughout evolution has expanded the complexity in transcription initiation. Furthermore, recent studies have emerged that questioned the centrality of TBP in mammalian cells, particularly in Pol II transcription, but the role of TBP and its paralogs in Pol I transcription remains to be re-evaluated.
View Article and Find Full Text PDFMitosis involves intricate steps, such as DNA condensation, nuclear membrane disassembly, and phosphorylation cascades that temporarily halt gene transcription. Despite this disruption, daughter cells remarkably retain the parent cell's gene expression pattern, allowing for efficient transcriptional memory after division. Early studies in mammalian cells suggested that transcription factors (TFs) mark genes for swift reactivation, a phenomenon termed 'mitotic bookmarking', but conflicting data emerged regarding TF presence on mitotic chromosomes.
View Article and Find Full Text PDFBy exploiting their inherent elasticity, focus-variable silicone lenses shift their focal length reversibly when deformed. Although biconcave and meniscus lenses contribute to optical systems just as well as biconvex lenses, studies primarily revolve around the latter. Thus, we aim to reveal the focal length shifting potential of all aforementioned lens types.
View Article and Find Full Text PDFA large number of transcription factors have been shown to bind and interact with mitotic chromosomes, which may promote the efficient reactivation of transcriptional programs following cell division. Although the DNA-binding domain (DBD) contributes strongly to TF behavior, the mitotic behaviors of TFs from the same DBD family may vary. To define the mechanisms governing TF behavior during mitosis in mouse embryonic stem cells, we examined two related TFs: Heat Shock Factor 1 and 2 (HSF1 and HSF2).
View Article and Find Full Text PDFTriatoma costalimai and Triatoma jatai are related species, which occur in sympatry in Paranã, Tocantins, Brazil, in rocky outcrops and in peridomicile and intradomicile environments. This study compared morphologic and morphometric aspects of the eggs of these species using optical microscopy (OM) and scanning electron microscopy (SEM). Operculum cells (OP) and egg body (EB) were drawn and photographed, their surfaces were measured, and spots were quantified.
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