"Border cell"

The expression changes of high-mobility group box 1 (HMGB1) in the mouse cochlea have recently been implicated in noise-induced hearing loss, suggesting that HMGB1 participates in regulating cochlear function. However, the precise role of HMGB1 in the auditory system remains largely unclear. This study aimed to investigate its function in the developing mouse cochlea by examining the expression pattern of HMGB1 in the mouse cochlea from embryonic day (E) 18.5 to postnatal day (P) 28 using double immunofluorescence on frozen sections...

The classical notion of a 'language of thought' (LoT), advanced prominently by the philosopher Jerry Fodor, is an influential position in cognitive science whereby the mental representations underpinning thought are considered to be compositional and productive, enabling the construction of new complex thoughts from more primitive symbolic concepts. LoT theory has been challenged because a neural implementation has been deemed implausible. We disagree. Examples of critical computational ingredients needed for a neural implementation of a LoT have in fact been demonstrated, in particular in the hippocampal spatial navigation system of rodents...

Chemotaxis drives diverse migrations important for development and involved in diseases, including cancer progression. Using border cells in the Drosophila egg chamber as a model for collective cell migration, we characterized the role of ArfGAP1 in regulating chemotaxis during this process. We found that ArfGAP1 is required for the maintenance of receptor tyrosine kinases, the guidance receptors, at the plasma membrane. In the absence of ArfGAP1, the level of active receptors is reduced at the plasma membrane and increased in late endosomes...

Collective cell migration occurs in various biological processes such as development, wound healing and metastasis. During Drosophila oogenesis, border cells (BC) form a cluster that migrates collectively inside the egg chamber. The Ste20-like kinase Misshapen (Msn) is a key regulator of BC migration coordinating the restriction of protrusion formation and contractile forces within the cluster. Here, we demonstrate that the kinase Tao acts as an upstream activator of Msn in BCs. Depletion of Tao significantly impedes BC migration and produces a phenotype similar to Msn loss-of-function...

A key regulator of collective cell migration is prostaglandin (PG) signaling. However, it remains largely unclear whether PGs act within the migratory cells or their microenvironment to promote migration. Here we use Drosophila border cell migration as a model to uncover the cell-specific roles of two PGs in collective migration. Prior work shows PG signaling is required for on-time migration and cluster cohesion. We find that the PGE 2 synthase cPGES is required in the substrate, while the PGF 2α synthase Akr1B is required in the border cells for on-time migration...

Migrating cell collectives navigate complex tissue environments both during normal development and in pathological contexts such as tumor invasion and metastasis. To do this, cells in collectives must stay together but also communicate information across the group. The cadherin superfamily of proteins mediates junctional adhesions between cells, but also serve many essential functions in collective cell migration. Besides keeping migrating cell collectives cohesive, cadherins help follower cells maintain their attachment to leader cells, transfer information about front-rear polarity among the cohort, sense and respond to changes in the tissue environment, and promote intracellular signaling, in addition to other cellular behaviors...

The basement membrane (BM) is a specialized extracellular matrix (ECM), which underlies or encases developing tissues. Mechanical properties of encasing BMs have been shown to profoundly influence the shaping of associated tissues. Here, we use the migration of the border cells (BCs) of the Drosophila egg chamber to unravel a new role of encasing BMs in cell migration. BCs move between a group of cells, the nurse cells (NCs), that are enclosed by a monolayer of follicle cells (FCs), which is, in turn, surrounded by a BM, the follicle BM...

Septins self-assemble into polymers that bind and deform membranes in vitro and regulate diverse cell behaviors in vivo. How their in vitro properties relate to their in vivo functions is under active investigation. Here, we uncover requirements for septins in detachment and motility of border cell clusters in the Drosophila ovary. Septins and myosin colocalize dynamically at the cluster periphery and share phenotypes but, surprisingly, do not impact each other. Instead, Rho independently regulates myosin activity and septin localization...

Having intact epithelial tissues is critical for embryonic development and adult homeostasis. How epithelia respond to damaging insults or tissue growth while still maintaining intercellular connections and barrier integrity during development is poorly understood. The conserved small GTPase Rap1 is critical for establishing cell polarity and regulating cadherin-catenin cell junctions. Here, we identified a new role for Rap1 in maintaining epithelial integrity and tissue shape during Drosophila oogenesis. Loss of Rap1 activity disrupted the follicle cell epithelium and the shape of egg chambers during a period of major growth...

We propose a mechanism enabling the appearance of border cells-neurons firing at the boundaries of the navigated enclosures. The approach is based on the recent discovery of discrete complex analysis on a triangular lattice, which allows constructing discrete epitomes of complex-analytic functions and making use of their inherent ability to attain maximal values at the boundaries of generic lattice domains. As it turns out, certain elements of the discrete-complex framework readily appear in the oscillatory models of grid cells...

BACKGROUND: Published reports regarding the tissue types that surround the internal carotid artery (ICA) as it travels through the carotid canal vary. Reports have variably defined this membrane as periosteum, loose areolar tissue, or dura mater. With such discrepancies and realizing that knowledge of this tissue might be important for skull base surgeons who expose or mobilize the ICA at this location, the present anatomical/histological study was performed. METHODS: In 8 adult cadavers (16 sides), the contents of the carotid canal were evaluated; specifically, the membrane surrounding the petrous part of the ICA was studied, and its relationship to the deeper lying artery was observed...

INTRODUCTION: The competitive strategies of plants play a crucial role in their growth. Allelopathy is one of the weapons that plants use to improve their competitive advantage. METHODS: In order to explore the competitive strategy of a poisonous weed Elsholtzia densa Benth. ( E. densa ) on the Qinghai-Tibet Plateau (QTP), the effects of decomposing substances of E. densa on growth, root border cells (RBCs) characteristics of highland crop highland barley ( Hordeum vulgare L...

Chronic subdural hematoma (cSDH) is an encapsulated collection of blood and blood degradation products between dural border cell layers, the pathophysiology of formation and expansion of which is still debatable. It is usually seen in the elderly population, and surgical evacuation is the primary mode of treatment. The main hurdle in the treatment of cSDH is postoperative recurrences and the need for repeat operations. A few authors have classified cSDH into homogenous, gradation, separated, trabecular, and laminar types based on the internal architecture of hematoma and proposed that separated, laminar, and gradation types of cSDH have a high propensity of recurrence after surgery...

Actin networks are central to shaping and moving cells during animal development. Various spatial cues activate conserved signal transduction pathways to polarize actin network assembly at sub-cellular locations and to elicit specific physical changes. Actomyosin networks contract and Arp2/3 networks expand, and to affect whole cells and tissues they do so within higher-order systems. At the scale of tissues, actomyosin networks of epithelial cells can be coupled via adherens junctions to form supracellular networks...

BACKGROUND: High-mobility group AT-hook protein 2 (HMGA2) is a gene regulatory protein that is correlated with metastatic potential and poor prognosis. It has been shown that HMGA2 is overexpressed in various tumors such as lung cancer or pancreatic cancer. The invasive character and highly aggressive structure of glioblastoma let us to investigate HMGA2 expression in the border zone of the tumor more closely. We compared HMGA2 expression between glioblastoma and normal brain tissue. In addition, we analyzed and compared HMGA2 expression in the border and center zones of tumors...

Enterocyte invasion by the gastrointestinal pathogen Salmonella enterica is accompanied by loss of brush border and massive remodeling of the actin cytoskeleton, leading to microvilli effacement and formation of membrane ruffles. These manipulations are mediated by effector proteins translocated by the Salmonella Pathogenicity Island 1-encoded type III secretion system (SPI1-T3SS). To unravel the mechanisms of microvilli effacement and contribution of SPI1-T3SS effector proteins, the dynamics of host-pathogen interactions was analyzed using live cell imaging (LCI) of polarized epithelial cells (PEC) expressing LifeAct-GFP...

INTRODUCTION: Drosophila Singed (mammalian Fascin) is an actin-binding protein that is known mainly for bundling parallel actin filaments. Among many functions of Singed, it is required for cell motility for both Drosophila and mammalian systems. Increased Fascin-1 levels positively correlate with greater metastasis and poor prognosis in human cancer. Border cell cluster, forms and migrates during Drosophila egg chamber development, shows higher expression of Singed compared with other follicle cells...

Plants have to cope with a myriad of soilborne pathogens that affect crop production and food security. The complex interactions between the root system and microorganisms are determinant for the whole plant health. However, the knowledge regarding root defense responses is limited as compared to the aerial parts of the plant. Immune responses in roots appear to be tissue-specific suggesting a compartmentalization of defense mechanisms in these organs. The root cap releases cells termed root "associated cap-derived cells" (AC-DCs) or "border cells" embedded in a thick mucilage layer forming the root extracellular trap (RET) dedicated to root protection against soilborne pathogens...

Specification of migratory cell fate from a stationary population is complex and indispensable both for metazoan development as well for the progression of the pathological condition like tumor metastasis. Though this cell fate transformation is widely prevalent, the molecular understanding of this phenomenon remains largely elusive. We have employed the model of border cells (BC) in Drosophila oogenesis and identified germline activity of an RNA binding protein, Cup that limits acquisition of migratory cell fate from the neighbouring follicle epithelial cells...

Drosophila border cells have emerged as a genetically tractable model to investigate dynamic collective cell migration within the context of a developing organ. Studies of live border cell cluster migration have revealed similarities with other migrating collectives, including formation and restriction of cellular protrusions to the front of the cluster, supracellular actomyosin contractility of the entire collective, and intra-collective cell motility. Here, we describe protocols to prepare ex vivo cultures of stage 9 egg chambers followed by live time-lapse imaging of fluorescently labeled border cells to image dynamic cell behaviors...