Induction of a proliferative response in the zebrafish retina by injection of extracellular vesicles.

Ongoing research using cell transplantation and viral-mediated gene therapy has been making progress to restore vision by retinal repair, but targeted delivery and complete cellular integration remain challenging. An alternative approach is to induce endogenous Müller glia (MG) to regenerate lost neurons and photoreceptors, as occurs spontaneously in teleost fish and amphibians. Extracellular vesicles (EVs) can transfer protein and RNA cargo between cells serving as a novel means of cell-cell communication.

The miR-216a-Dot1l Regulatory Axis Is Necessary and Sufficient for Müller Glia Reprogramming during Retina Regeneration.

Unlike the adult mammalian retina, Müller glia (MG) in the adult zebrafish retina are able to dedifferentiate into a "stem cell"-like state and give rise to multipotent progenitor cells upon retinal damage. We show that miR-216a is downregulated in MG after constant intense light lesioning and that miR-216a suppression is necessary and sufficient for MG dedifferentiation and proliferation during retina regeneration. miR-216a targets the H3K79 methyltransferase Dot1l, which is upregulated in proliferating MG after retinal damage.

Neurotransmitter-Regulated Regeneration in the Zebrafish Retina.

Current efforts to repair damaged or diseased mammalian retinas are inefficient and largely incapable of fully restoring vision. Conversely, the zebrafish retina is capable of spontaneous regeneration upon damage using Müller glia (MG)-derived progenitors. Understanding how zebrafish MG initiate regeneration may help develop new treatments that prompt mammalian retinas to regenerate.

Power tools for gene expression and clonal analysis in Drosophila.

The development of two-component expression systems in Drosophila melanogaster, one of the most powerful genetic models, has allowed the precise manipulation of gene function in specific cell populations. These expression systems, in combination with site-specific recombination approaches, have also led to the development of new methods for clonal lineage analysis. We present a hands-on user guide to the techniques and approaches that have greatly increased resolution of genetic analysis in the fly, with a special focus on their application for lineage analysis.

Neuron-type specific regulation of a 3'UTR through redundant and combinatorially acting cis-regulatory elements.

3' Untranslated region (UTR)-dependent post-transcriptional regulation has emerged as a critical mechanism of controlling gene expression in various physiological contexts, including cellular differentiation events. Here, we examine the regulation of the 3'UTR of the die-1 transcription factor in a single neuron of the nematode C. elegans.

Extracellular sugar modifications provide instructive and cell-specific information for axon-guidance choices.

Heparan sulfates (HSs) are extraordinarily complex extracellular sugar molecules that are critical components of multiple signaling systems controlling neuronal development. The molecular complexity of HSs arises through a series of specific modifications, including sulfations of sugar residues and epimerizations of their glucuronic acid moieties. The modifications are introduced nonuniformly along protein-attached HS polysaccharide chains by specific enzymes.

Molecular architecture of a miRNA-regulated 3' UTR.

Animal genomes contain hundreds of microRNAs (miRNAs), small regulatory RNAs that control gene expression by binding to complementary sites in target mRNAs. Some rules that govern miRNA/target interaction have been elucidated but their general applicability awaits further experimentation on a case-by-case basis. We use here an assay system in transgenic nematodes to analyze the interaction of the Caenorhabditis elegans lsy-6 miRNA with 3' UTR sequences.

Genetic screens for Caenorhabditis elegans mutants defective in left/right asymmetric neuronal fate specification.

We describe here the results of genetic screens for Caenorhabditis elegans mutants in which a single neuronal fate decision is inappropriately executed. In wild-type animals, the two morphologically bilaterally symmetric gustatory neurons ASE left (ASEL) and ASE right (ASER) undergo a left/right asymmetric diversification in cell fate, manifested by the differential expression of a class of putative chemoreceptors and neuropeptides. Using single cell-specific gfp reporters and screening through a total of almost 120,000 haploid genomes, we isolated 161 mutants that define at least six different classes of mutant phenotypes in which ASEL/R fate is disrupted.

Perfect seed pairing is not a generally reliable predictor for miRNA-target interactions.

We use Caenorhabditis elegans to test proposed general rules for microRNA (miRNA)-target interactions. We show that G.U base pairing is tolerated in the 'seed' region of the lsy-6 miRNA interaction with its in vivo target cog-1, and that 6- to 8-base-pair perfect seed pairing is not a generally reliable predictor for an interaction of lsy-6 with a 3' untranslated region (UTR).

Ex vivo induction and expansion of antigen-specific cytotoxic T cells by HLA-Ig-coated artificial antigen-presenting cells.

Adoptive immunotherapy holds promise as a treatment for cancer and infectious diseases, but its development has been impeded by the lack of reproducible methods for generating therapeutic numbers of antigen-specific CD8(+) cytotoxic T lymphocytes (CTLs). As a result, there are only limited reports of expansion of antigen-specific CTLs to the levels required for clinical therapy. To address this issue, artificial antigen-presenting cells (aAPCs) were made by coupling a soluble human leukocyte antigen-immunoglobulin fusion protein (HLA-Ig) and CD28-specific antibody to beads.