Notch controls the cell cycle to define leader versus follower identities during collective cell migration.

Coordination of cell proliferation and migration is fundamental for life, and its dysregulation has catastrophic consequences, such as cancer. How cell cycle progression affects migration, and vice versa, remains largely unknown. We address these questions by combining in silico modelling and in vivo experimentation in the zebrafish trunk neural crest (TNC).

Zebrafish Cdx4 regulates neural crest cell specification and migratory behaviors in the posterior body.

The neural crest (NC) is a transient multipotent cell population that migrates extensively to produce a remarkable array of vertebrate cell types. NC cell specification progresses in an anterior to posterior fashion, resulting in distinct, axial-restricted subpopulations. The anterior-most, cranial, population of NC is specified as gastrulation concludes and neurulation begins, while more posterior populations become specified as the body elongates.

Midline morphogenesis of zebrafish foregut endoderm is dependent on Hoxb5b.

During vertebrate embryonic development complex morphogenetic events drive the formation of internal organs associated with the developing digestive tract. The foregut organs derive from hepatopancreatic precursor cells that originate bilaterally within the endoderm monolayer, and subsequently converge toward the midline where they coalesce to produce the gut tube from which the liver and pancreas form. The progenitor cells of these internal organs are influenced by the lateral plate mesoderm (LPM), which helps direct them towards their specific fates.

Occurrence and biodegradation of hydrocarbons at high salinities.

Hypersaline environments are found around the world, above and below ground, and many are exposed to hydrocarbons on a continuous or a frequent basis. Some surface hypersaline environments are exposed to hydrocarbons because they have active petroleum seeps while others are exposed because of oil exploration and production, or nearby human activities. Many oil reservoirs overlie highly saline connate water, and some national oil reserves are stored in salt caverns.

From head to tail: regionalization of the neural crest.

The neural crest is regionalized along the anteroposterior axis, as demonstrated by foundational lineage-tracing experiments that showed the restricted developmental potential of neural crest cells originating in the head. Here, we explore how recent studies of experimental embryology, genetic circuits and stem cell differentiation have shaped our understanding of the mechanisms that establish axial-specific populations of neural crest cells. Additionally, we evaluate how comparative, anatomical and genomic approaches have informed our current understanding of the evolution of the neural crest and its contribution to the vertebrate body.

Development and migration of the zebrafish rhombencephalic octavolateral efferent neurons.

In vertebrate animals, motor and sensory efferent neurons carry information from the central nervous system (CNS) to peripheral targets. These two types of efferent systems sometimes bear a close resemblance, sharing common segmental organization, axon pathways, and chemical messengers. Here, we focus on the development of the octavolateral efferent neurons (OENs) and their interactions with the closely-related facial branchiomotor neurons (FBMNs) in zebrafish.

Rapid image deconvolution and multiview fusion for optical microscopy.

The contrast and resolution of images obtained with optical microscopes can be improved by deconvolution and computational fusion of multiple views of the same sample, but these methods are computationally expensive for large datasets. Here we describe theoretical and practical advances in algorithm and software design that result in image processing times that are tenfold to several thousand fold faster than with previous methods. First, we show that an 'unmatched back projector' accelerates deconvolution relative to the classic Richardson-Lucy algorithm by at least tenfold.

Neural crest development: insights from the zebrafish.

Our understanding of the neural crest, a key vertebrate innovation, is built upon studies of multiple model organisms. Early research on neural crest cells (NCCs) was dominated by analyses of accessible amphibian and avian embryos, with mouse genetics providing complementary insights in more recent years. The zebrafish model is a relative newcomer to the field, yet it offers unparalleled advantages for the study of NCCs.

Use of a Hepatitis C Screening Order Set to Improve Screening Rates and Measure Intervention Effectiveness.

Introduction: Hepatitis C virus (HCV) infection leads to significant morbidity and mortality. Rates of HCV infection are greatest in patients born from 1945 to 1965, so the Centers for Disease Control recommends a one-time screening in this cohort. Previous interventions utilizing the electronic medical record (EMR) capabilities at two University of Utah Family Medicine clinics have increased screening rates significantly, but further improvement is possible.

Prickle1 is required for EMT and migration of zebrafish cranial neural crest.

The neural crest-a key innovation of the vertebrates-gives rise to diverse cell types including melanocytes, neurons and glia of the peripheral nervous system, and chondrocytes of the jaw and skull. Proper development of the cephalic region is dependent on the tightly-regulated specification and migration of cranial neural crest cells (NCCs). The core PCP proteins Frizzled and Disheveled have previously been implicated in NCC migration.

Zebrafish Pancreas Development and Regeneration: Fishing for Diabetes Therapies.

The zebrafish pancreas shares its basic organization and cell types with the mammalian pancreas. In addition, the developmental pathways that lead to the establishment of the pancreatic islets of Langherhans are generally conserved from fish to mammals. Zebrafish provides a powerful tool to probe the mechanisms controlling establishment of the pancreatic endocrine cell types from early embryonic progenitor cells, as well as the regeneration of endocrine cells after damage.

Chronic alcohol feeding potentiates hormone-induced calcium signalling in hepatocytes.

Chronic alcohol consumption causes a spectrum of liver diseases, but the pathogenic mechanisms driving the onset and progression of disease are not clearly defined. We show that chronic alcohol feeding sensitizes rat hepatocytes to Ca -mobilizing hormones resulting in a leftward shift in the concentration-response relationship and the transition from oscillatory to more sustained and prolonged Ca increases. Our data demonstrate that alcohol-dependent adaptation in the Ca signalling pathway occurs at the level of hormone-induced inositol 1,4,5 trisphosphate (IP ) production and does not involve changes in the sensitivity of the IP receptor or size of internal Ca stores.

Individualized risk prediction of outcomes for oral cavity cancer patients.

Background: Optimal management of oral cancer relies upon accurate and individualized risk prediction of relevant clinical outcomes. Individualized prognostic calculators have been developed to guide patient-physician communication and treatment-related decision-making. However it is critical to scrutinize their accuracy prior to integrating into clinical care.

Differential levels of Neurod establish zebrafish endocrine pancreas cell fates.

During development a network of transcription factors functions to differentiate foregut cells into pancreatic endocrine cells. Differentiation of appropriate numbers of each hormone-expressing endocrine cell type is essential for the normal development of the pancreas and ultimately for effective maintenance of blood glucose levels. A fuller understanding of the details of endocrine cell differentiation may contribute to development of cell replacement therapies to treat diabetes.

Rest represses maturation within migrating facial branchiomotor neurons.

The vertebrate brain arises from the complex organization of millions of neurons. Neurogenesis encompasses not only cell fate specification from neural stem cells, but also the terminal molecular and morphological maturation of neurons at correct positions within the brain. RE1-silencing transcription factor (Rest) is expressed in non-neural tissues and neuronal progenitors where it inhibits the terminal maturation of neurons by repressing hundreds of neuron-specific genes.

Reliable encoding of stimulus intensities within random sequences of intracellular Ca2+ spikes.

Ca(2+) is a ubiquitous intracellular messenger that regulates diverse cellular activities. Extracellular stimuli often evoke sequences of intracellular Ca(2+) spikes, and spike frequency may encode stimulus intensity. However, the timing of spikes within a cell is random because each interspike interval has a large stochastic component.

Facial motor neuron migration advances.

During development, the migration of specific neuronal subtypes is required for the correct establishment of neural circuits. In mice and zebrafish, facial branchiomotor (FBM) neurons undergo a tangential migration from rhombomere 4 caudally through the hindbrain. Recent advances in the field have capitalized on genetic studies in zebrafish and mouse, and high-resolution time-lapse imaging in zebrafish.

Transgenic zebrafish model of the C43G human insulin gene mutation.

Aims/introduction: The human insulin gene/preproinsulin protein mutation C43G disrupts disulfide bond formation and causes diabetes in humans. Previous in vitro studies showed that these mutant proteins are retained in the endoplasmic reticulum (ER), are not secreted and are associated with decreased secretion of wild-type insulin. The current study extends this work to an in vivo zebrafish model.

Axon tracts guide zebrafish facial branchiomotor neuron migration through the hindbrain.

Appropriate localization of neurons within the brain is a crucial component of the establishment of neural circuitry. In the zebrafish hindbrain, the facial branchiomotor neurons (FBMNs) undergo a chain-like tangential migration from their birthplace in rhombomere (r) 4 to their final destination in r6/r7. Here, we report that ablation of either the cell body or the trailing axon of the leading FBMN, or 'pioneer' neuron, blocks the migration of follower FBMNs into r5.

Zebrafish rest regulates developmental gene expression but not neurogenesis.

The transcriptional repressor Rest (Nrsf) recruits chromatin-modifying complexes to RE1 'silencer elements', which are associated with hundreds of neural genes. However, the requirement for Rest-mediated transcriptional regulation of embryonic development and cell fate is poorly understood. Conflicting views of the role of Rest in controlling cell fate have emerged from recent studies.

Mnx1: a gatekeeper of β cell fate.

A full understanding of embryonic endocrine pancreas development will be key to the establishment of islet replacement strategies. In particular, it is important to identify molecular pathways that establish the correct balance of specific endocrine pancreatic islet cell types. Recently, our work in the zebrafish has revealed that the correct ratio of α and β cell fates depends on the homeodomain transcription factor Mnx1 (Hb9); in the absence of functional Mnx1, β cell precursors give rise to α cells.

Expression and retinoic acid regulation of the zebrafish nr2f orphan nuclear receptor genes.

Background: The vertebrate nuclear receptor subfamily 2, group f (nr2f) genes encode orphan receptors that have the capacity to act as negative regulators of retinoic acid (RA) signaling.

Results: We describe embryonic and larval expression of four of the six zebrafish nr2f genes, nr2f1a, nr2f1b, nr2f2, and nr2f5. These genes show highly regulated patterns of expression within the central nervous system, including in the developing hindbrain, as well as in the mesoderm and endoderm.