Tagging of individual embryos with electronic p-Chips.

Collecting information about biochemical processes occurring inside a single cell or embryo is traditionally done either using fluorescent dyes with microscopy or via microelectrode voltage-clamp techniques. This paper demonstrates that a more direct method - transmission of information using an electronic chip implanted in an embryo - is feasible. A light-activated microtransponder with dimensions 250 μm × 250 μm × 100 μm (a "p-Chip") was implanted into a blastula-stage frog (Xenopus laevis) embryo.

Eating disorder predisposition is associated with ESRRA and HDAC4 mutations.

Anorexia nervosa and bulimia nervosa are common and severe eating disorders (EDs) of unknown etiology. Although genetic factors have been implicated in the psychopathology of EDs, a clear biological pathway has not been delineated. DNA from two large families affected by EDs was collected, and mutations segregating with illness were identified by whole-genome sequencing following linkage mapping or by whole-exome sequencing.

Neuroprotective efficacy of aminopropyl carbazoles in a mouse model of Parkinson disease.

We previously reported the discovery of P7C3, an aminopropyl carbazole having proneurogenic and neuroprotective properties in newborn neural precursor cells of the dentate gyrus. Here, we provide evidence that P7C3 also protects mature neurons in brain regions outside of the hippocampus. P7C3 blocks 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-mediated cell death of dopaminergic neurons in the substantia nigra of adult mice, a model of Parkinson disease (PD).

Neuroprotective efficacy of aminopropyl carbazoles in a mouse model of amyotrophic lateral sclerosis.

We previously reported the discovery of P7C3, an aminopropyl carbazole having proneurogenic and neuroprotective properties in newborn neural precursor cells of the hippocampal dentate gyrus. We have further found that chemicals having efficacy in this in vivo screening assay also protect dopaminergic neurons of the substantia nigra following exposure to the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, a mouse model of Parkinson disease. Here, we provide evidence that an active analog of P7C3, known as P7C3A20, protects ventral horn spinal cord motor neurons from cell death in the G93A-SOD1 mutant mouse model of amyotrophic lateral sclerosis (ALS).

Preoperative assessment for children requiring dental treatment under general anesthesia.

Objective: This study aimed to describe children <6 years requiring general anesthesia for dental treatment and factors associated with a change in medical management prior to surgery.

Study Design: This case series reviewed the past medical history and preoperative assessment of patients referred for dental preoperative evaluations at a single institution (2005-2008). A "deflection" was defined as a recommendation to change preoperative or operative care based on the preoperative assessment.

Axolotl pronephric duct migration requires an epidermally derived, laminin 1-containing extracellular matrix and the integrin receptor alpha6beta1.

The epidermis overlying the migrating axolotl pronephric duct is known to participate in duct guidance. This epidermis deposits an extracellular matrix onto the migrating duct and its pathway that is a potential source of directional guidance cues. The role of this matrix in pronephric duct guidance was assayed by presenting matrix deposited on microcarriers directly to migrating pronephric ducts in situ.

The color purple: analyzing alkaline phosphatase expression in experimentally manipulated sea urchin embryos in an undergraduate developmental biology course.

In these laboratory exercises, developed for a sophomore/junior-level undergraduate course in Developmental Biology, students explore the processes of differentiation and morphogenesis in sea urchin embryos by monitoring the spatio-temporal expression pattern of the endoderm marker, alkaline phosphatase. Once students have determined the normal alkaline phosphatase expression pattern, they are asked to treat sea urchin embryos in some way that perturbs normal morphogenesis. Their task is to discover whether the chosen treatment perturbs both morphogenesis and differentiation of the gut or only morphogenesis.

Pronephric duct extension in amphibian embryos: migration and other mechanisms.

Initiation of excretory system development in all vertebrates requires (1) delamination of the pronephric and pronephric duct rudiments from intermediate mesoderm at the ventral border of anterior somites, and (2) extension of the pronephric duct to the cloaca. Pronephric duct extension is the central event in nephric system development; the pronephric duct differentiates into the tubule that carries nephric filtrate out of the body and induces terminal differentiation of adult kidneys. Early studies concluded that pronephric ducts formed by means of in situ segregation of pronephric duct tissue from lateral mesoderm ventral to the forming somites; more recent studies highlight caudal migration of the pronephric duct as the major morphogenetic mechanism.

GDNF and GFRalpha-1 are components of the axolotl pronephric duct guidance system.

In mammals, secretion of GDNF by the metanephrogenic mesenchyme is essential for branching morphogenesis of the ureteric bud and, thus, metanephric development. However, the expression pattern of GDNF and its receptor complex-the GPI-linked ligand-binding protein, GFRalpha-1, and the Ret tyrosine kinase signaling protein-indicates that it could operate at early steps in kidney development as well. Furthermore, the developing nephric systems of fish and amphibian embryos express components of the GDNF signaling system even though they do not make a metanephros.

Elongation of axolotl tailbud embryos requires GPI-linked proteins and organizer-induced, active, ventral trunk endoderm cell rearrangements.

Application of phosphatidylinositol-specific phospholipase C to early tailbud stage axolotl embryos reveals that a specific subset of morphogenetic movements requires glycosylphosphatidylinositol (GPI)-linked cell-surface proteins. These include pronephric duct extension, "gill bulge" formation, and embryonic elongation along the anteroposterior axis. The work of Kitchin (1949, J.

Morphogenesis of the axolotl pronephric duct: a model system for the study of cell migration in vivo.

Pronephric duct (PND) morphogenesis is a critical early event in the development of the vertebrate excretory system. This structure is the exit channel for both pronephric and mesonephric filtrate, forms the ureteric bud of the metanephros and gives rise to the ductus deferens of the testis. In addition, the PND and ureteric bud epithelia induce terminal differentiation of the mesonephric and metanephric mesenchyme, respectively.

The epidermis is a source of directional information for the migrating pronephric duct in Ambystoma mexicanum embryos.

In the urodele Ambystoma mexicanum, the pronephric duct (PND) is formed from a coherent group of cells that migrate from the pronephros to the cloaca along a pathway immediately ventral to the developing somites. The guidance cues used by the migrating PND primordium to find the cloaca are a local property of the migration substratum, are temporally regulated, and are both polarized and oriented. Since the pronephric duct migrates between two tissues--the underlying lateral mesoderm and the overlying epidermis--we performed a study to identify the tissue(s) in which PND guidance cues originate.

Polyribosome targeting to microtubules: enrichment of specific mRNAs in a reconstituted microtubule preparation from sea urchin embryos.

A subset of mRNAs, polyribosomes, and poly(A)-binding proteins copurify with microtubules from sea urchin embryos. Several lines of evidence indicate that the interaction of microtubules with ribosomes is specific: a distinct stalk-like structure appears to mediate their association; ribosomes bind to microtubules with a constant stoichiometry through several purification cycles; and the presence of ribosomes in these preparations depends on the presence of intact microtubules. Five specific mRNAs are enriched with the microtubule-bound ribosomes, indicating that translation of specific proteins may occur on the microtubule scaffolding in vivo.

Three populations of migrating amphibian embryonic cells utilize different guidance cues.

Previous investigations designed to identify the molecule(s) governing the directed migration of the amphibian pronephric duct (PND) revealed a requirement for a glycosyl phosphatidylinositol (GPI)-linked cell surface molecule, possibly the ectoenzyme alkaline phosphatase (AP). Cranial neural crest cells (CNC) grafted to the flank migrate along the same pathways as the PND, suggesting that PND and CNC guidance systems might have a common molecular basis. Both PND and CNC migration pathways display AP.

Identification and characterization of the poly(A)-binding proteins from the sea urchin: a quantitative analysis.

Poly(A)-binding proteins (PABPs) are the best characterized messenger RNA-binding proteins of eucaryotic cells and have been identified in diverse organisms such as mammals and yeasts. The in vitro poly(A)-binding properties of these proteins have been studied intensively; however, little is known about their function in cells. In this report, we show that sea urchin eggs have two molecular weight forms of PABP (molecular weights of 66,000 and 80,000).