Cnn3 regulates neural tube morphogenesis and neuronal stem cell properties.

Calponin 3 (Cnn3) is a member of the Cnn family of actin-binding molecules that is highly expressed in the mammalian brain and has been shown to control dendritic spine morphology, density, and plasticity by regulating actin cytoskeletal reorganization and dynamics. However, little is known about the role of Cnn3 during embryonic development. In this study, we analyzed mutant animals deficient in Cnn3 to gain a better understanding of its role in brain morphogenesis.

Trimethylation and Acetylation of β-Catenin at Lysine 49 Represent Key Elements in ESC Pluripotency.

Wnt/β-catenin signaling is required for embryonic stem cell (ESC) pluripotency by inducing mesodermal differentiation and inhibiting neuronal differentiation; however, how β-catenin counter-regulates these differentiation pathways is unknown. Here, we show that lysine 49 (K49) of β-catenin is trimethylated (β-catMe3) by Ezh2 or acetylated (β-catAc) by Cbp. Significantly, β-catMe3 acts as a transcriptional co-repressor of the neuronal differentiation genes sox1 and sox3, whereas β-catAc acts as a transcriptional co-activator of the key mesodermal differentiation gene t-brachyury (t-bra).

Presynaptic localization of GluK5 in rod photoreceptors suggests a novel function of high affinity glutamate receptors in the mammalian retina.

Kainate receptors mediate glutamatergic signaling through both pre- and presynaptic receptors. Here, we studied the expression of the high affinity kainate receptor GluK5 in the mouse retina. Double-immunofluoresence labeling and electron microscopic analysis revealed a presynaptic localization of GluK5 in the outer plexiform layer.

Beta-catenin is vital for the integrity of mouse embryonic stem cells.

β-Catenin mediated Wnt-signaling is assumed to play a major function in embryonic stem cells in maintaining their stem cell character and the exit from this unique trait. The complexity of β-catenin action and conflicting results on the role of β-catenin in maintaining the pluripotent state have made it difficult to understand its precise cellular and molecular functions. To attempt this issue we have generated new genetically modified mouse embryonic stem cell lines allowing for the deletion of β-catenin in a controlled manner by taking advantage of the Cre-ER-T2 system and analyzed the effects in a narrow time window shortly after ablation.

Reelin together with ApoER2 regulates interneuron migration in the olfactory bulb.

One pathway regulating the migration of neurons during development of the mammalian cortex involves the extracellular matrix protein Reelin. Reelin and components of its signaling cascade, the lipoprotein receptors ApoER2 and Vldlr and the intracellular adapter protein Dab1 are pivotal for a correct layer formation during corticogenesis. The olfactory bulb (OB) as a phylogenetically old cortical region is known to be a prominent site of Reelin expression.

Role for Reelin in neurotransmitter release.

The extracellular matrix molecule Reelin is known to control neuronal migration during development. Recent evidence suggests that it also plays a role in the maturation of postsynaptic dendrites and spines as well as in synaptic plasticity. Here, we aimed to address the question whether Reelin plays a role in presynaptic structural organization and function.

Compensatory growth mechanisms regulated by BMP and FGF signaling mediate liver regeneration in zebrafish after partial hepatectomy.

Here, we describe the zebrafish (Danio rerio) as a vertebrate model system to study liver regeneration with the added benefit of its powerful genetics and screening possibilities to uncover the molecular pathways underlying liver regeneration. We developed a partial hepatectomy (PH) protocol in zebrafish and investigated in detail the cellular and morphological changes during the process of liver regeneration. We show that the type of regenerative response is dependent on the size of the injury sustained by the zebrafish liver.

Postsynaptic and differential localization to neuronal subtypes of protocadherin beta16 in the mammalian central nervous system.

The formation of synapses is dependent on the expression of surface adhesion molecules that facilitate correct recognition, stabilization and function. The more than 60 clustered protocadherins (Pcdhalpha, Pcdhbeta and Pcdhgamma) identified in human and mouse have attracted considerable attention because of their clustered genomic organization and the potential role of alpha- and gamma-Pcdhs in allocating a neuronal surface code specifying synaptic connectivity. Here, we investigated whether beta-Pcdhs also contribute to these processes.

Divergent roles of ApoER2 and Vldlr in the migration of cortical neurons.

Reelin, its lipoprotein receptors [very low density lipoprotein receptor (Vldlr) and apolipoprotein E receptor 2 (ApoER2; also known as Lrp8)], and the cytoplasmic adaptor protein disabled 1 (Dab1) are important for the correct formation of layers in the cerebral cortex. Reeler mice lacking the reelin protein show altered radial neuronal migration resulting in an inversion of cortical layers. ApoER2 Vldlr double-knockout mutants and Dab1 mutants show a reeler-like phenotype, whereas milder phenotypes are found if only one of the two lipoprotein receptors for reelin is absent.

Gene replacement reveals a specific role for E-cadherin in the formation of a functional trophectoderm.

During mammalian embryogenesis the trophectoderm represents the first epithelial structure formed. The cell adhesion molecule E-cadherin is ultimately necessary for the transition from compacted morula to the formation of the blastocyst to ensure correct establishment of adhesion junctions in the trophectoderm. Here, we analyzed to what extent E-cadherin confers unique adhesion and signaling properties in trophectoderm formation in vivo.

Endoscope-assisted microsurgical resection of an intraneural ganglion cyst of the hypoglossal nerve.

An unusual case of an intraneural ganglion cyst of the hypoglossal nerve is presented. Only one case of this rare clinical entity has been reported previously. A 51-year-old woman presented with a 6-month history of left-sided hypoglossal nerve palsy.

Mammalian cadherins and protocadherins: about cell death, synapses and processing.

Cadherins have been known for a long time to be key elements in many important biological processes. In particular, the role of classical cadherins in mediating adhesion has been examined in great detail. Over recent years, the accumulation of experimental tools and mice mutants has allowed more refined analysis of cadherin functions, and new aspects such as signaling and synapse dynamics have become the center of interest.

Beta-catenin-mediated cell-adhesion is vital for embryonic forebrain development.

Forming a complex structure such as the mammalian brain requires a complex interplay between cells and different signalling cascades during embryonic development. beta-catenin plays pivotal roles in these processes by mediating cadherin-based cell adhesion and Wnt signalling. We show for the first time that beta-catenin functions predominantly as a mediator of cell adhesion during early development of the mammalian telencephalon.

Candidosis and aspergillosis as autopsy findings from 1994 to 2003.

We analysed the autopsy records of the Greifswald University Institute of Pathology (located in Eastern Germany) in respect of findings of candidosis and aspergillosis from 1994 to 2003. We also present eight immature aborted fetuses and premature infants with a mycosis. In a total of 2027 autopsies we found 164 cases of invasive candidosis and aspergillosis (8.

[Traumatic tympanic membrane perforactions. Local application of an alginate matrix loaded with epidermal growth factor in an animal model].

Background: The aim of this study was to evaluate the effects of an alginate matrix releasing epidermal growth factor on healing after acute tympanic membrane perforation in rats.

Method: A total of 20 male rats were divided into two groups. In each animal, a randomly chosen tympanic membrane was perforated by heat.

[An improved animal model for chronic perforation of the tympanic membrane].

Background: An inexpensive and valid animal model of chronic tympanic membrane perforation is needed.

Method: Twelve male rats were selected for different surgical procedures (subtotal tympanic membrane perforation with local microflaps, re-perforation without flaps, partial excision of the handle of malleus). The inhibition of spontaneous healing was accomplished by the application of prednisolon or mitomycin directly onto the tympanic membrane.

The CES-2-related transcription factor E4BP4 is an intrinsic regulator of motoneuron growth and survival.

The regulation of neuronal growth and survival during development requires interplay between extrinsic and intrinsic factors. Among the latter, transcription factors play a key role. In the nematode, the transcription factor CES-2 predisposes neurosecretory motoneurons to death, whereas E4BP4 (NFIL3), one of its vertebrate homologs, regulates survival of pro-B lymphocytes.

The supplementary diagnostic power of selected immunohistochemical, molecular genetic and infective parameters in epithelial hyperplastic laryngeal lesions.

Objectives: MIB-1 and p53 protein expression, loss of heterozygosity (LOH), microsatellite instability (MSI) of di- and mononucleotide repeats, and HPV status were tested for their potential to characterize different stages of epithelial hyperplastic laryngeal lesions (EHLL).

Methods: Thirty-two EHLL were reclassified according to the Ljubljana classification into simple (SH), abnormal (AbH), atypical hyperplasia (AtH) and carcinoma in situ, and investigated by immunohistochemical methods, PCR and direct sequencing analysis.

Results: MIB-1 increased with progressive grades of EHLL, whereas p53 protein expression was distinctive only between SH and AbH.

Resistance to rust ( Puccinia psidii Winter) in eucalyptus: mode of inheritance and mapping of a major gene with RAPD markers.

Rust is one of the most-damaging eucalypt diseases in Brazil and is considered a potential threat to eucalypt plantations worldwide. To determine the mode of inheritance of resistance in the Eucalyptus grandis- Puccinia psidii pathosystem, ten full-sib families, generated from crosses between susceptible and resistant trees, were inoculated with a single-pustule isolate of the pathogen and rust severity was scored. The observed segregation ratios in segregating families suggested major gene control of rust resistance, although clearly incomplete penetrance, variable expressivity and minor genes are also involved in the global rust-resistance response.

[Fibrolipoma of the larynx].

Benign mesenchymal tumors of the upper aerodigestive tract are very rare. In this localisation some tumors cause life-threatening upper airway obstruction. We report on a 42-year old man who complained dysphagia and globus sensation.

Long-term arterial pressure in spontaneously hypertensive rats is set by the kidney.

Objectives: We investigated whether arterial pressure in spontaneously hypertensive rats (SHR) can be normalized by a kidney graft from normotensive histocompatible donors. In addition, the effect of differential genetic predisposition to hypertension of recipients of an SHR kidney on the development of post-transplantation hypertension was studied.

Methods: SHR were transplanted with a kidney from congenic rats (BB.

GDNF and neurturin are target-derived factors essential for cranial parasympathetic neuron development.

During development, parasympathetic ciliary ganglion neurons arise from the neural crest and establish synaptic contacts on smooth and striate muscle in the eye. The factors that promote the ciliary ganglion pioneer axons to grow toward their targets have yet to be determined. Here, we show that glial cell line-derived neurotrophic factor (GDNF) and neurturin (NRTN) constitute target-derived factors for developing ciliary ganglion neurons.

The Phox2 homeodomain proteins are sufficient to promote the development of sympathetic neurons.

The development of sympathetic neurons is controlled by a network of transcriptional regulators, including the paired homeodomain proteins Phox2a and Phox2b. To understand the role of Phox2 proteins in more detail, the effect of Phox2 overexpression was analysed in the avian peripheral nervous system. Phox2a expression in neural crest cultures elicited a strong increase in the number of sympathoadrenergic cells.

Genetic diversity of the ectomycorrhizal fungus Pisolithus tinctorius based on RAPD-PCR analysis.

Twenty Pisolithus tinctorius isolates from different geographic locations and different hosts were characterized by the random amplified polymorphic DNA technique. Thirteen arbitrary primers generated 87 DNA fragments, all of them polymorphic. These data were used to calculate genetic distances among the isolates.

Onset of CNTFRalpha expression and signal transduction during neurogenesis in chick sensory dorsal root ganglia.

The expression of ciliary neurotrophic factor receptor alpha (CNTFRalpha) was investigated in the developing chick dorsal root ganglion (DRG) using affinity-purified anti-CNTFRalpha antibodies. At thoracic levels, CNTFRalpha-immunoreactivity (CNTFRalpha-IR) was first observed at stage 19 (E3) in cells with neuronal morphology. CNTFRalpha-IR is restricted to the neuronal lineage in the DRG throughout development.