Sir2 and Fun30 regulate ribosomal DNA replication timing via MCM helicase positioning and nucleosome occupancy.

The association between late replication timing and low transcription rates in eukaryotic heterochromatin is well known, yet the specific mechanisms underlying this link remain uncertain. In , the histone deacetylase Sir2 is required for both transcriptional silencing and late replication at the repetitive ribosomal DNA (rDNA) arrays. We have previously reported that in the absence of , a de-repressed RNA PolII repositions MCM replicative helicases from their loading site at the ribosomal origin, where they abut well-positioned, high-occupancy nucleosomes, to an adjacent region with lower nucleosome occupancy.

Unraveling Biogeographic Boundaries Within the Sierra Madre Oriental, México: An Endemicity Analysis Using a Taxonomically Diverse Dataset.

The Sierra Madre Oriental (SMO) is a significant mountain range and one of Mexico's 14 biogeographical provinces. Its delimitation has been debated. This study aims to analyze the distribution of plants, beetles, odonates, amphibians, reptiles, and mammals using an endemicity analysis to identify endemism areas and confirm the SMO's biogeographical units.

Longitudinal Relationships Across Bullying Victimization, Friendship and Social Support, and Internalizing Symptoms in Early-to-Middle Adolescence: A Developmental Cascades Investigation.

Current understanding of the longitudinal relationships between different aspects of peer relationships and mental health problems in early- to mid-adolescence is limited. In particular, the role played by gender in these developmental cascades processes is unclear, little is known about within-person effects between bullying victimization and internalizing symptoms, and the theorized benefits of friendship and social support are largely untested. Addressing these important research gaps, this study tested a number of theory-driven hypotheses (e.

Postrema area syndrome in the context of systemic lupus erythematosus: Case report.

Introduction: The area postrema, located on the floor of the fourth ventricle, regulates vomiting, fluid balance, osmoregulation, and immunomodulation. First documented in 1896, it has been a subject of scientific interest ever since. Area postrema syndrome (APS) is characterised by intractable nausea, vomiting, or hiccups, typically associated with neuromyelitis optica spectrum disorder (NMOSD).

Glutaminase-2 Expression Induces Metabolic Changes and Regulates Pyruvate Dehydrogenase Activity in Glioblastoma Cells.

Glutaminase controls the first step in glutaminolysis, impacting bioenergetics, biosynthesis and oxidative stress. Two isoenzymes exist in humans, GLS and GLS2. GLS is considered prooncogenic and overexpressed in many tumours, while GLS2 may act as prooncogenic or as a tumour suppressor.