In toto imaging of glial JNK signaling during larval zebrafish spinal cord regeneration.

Identification of signaling events that contribute to innate spinal cord regeneration in zebrafish can uncover new targets for modulating injury responses of the mammalian central nervous system. Using a chemical screen, we identify JNK signaling as a necessary regulator of glial cell cycling and tissue bridging during spinal cord regeneration in larval zebrafish. With a kinase translocation reporter, we visualize and quantify JNK signaling dynamics at single-cell resolution in glial cell populations in developing larvae and during injury-induced regeneration.

Apical polarity and actomyosin dynamics control Kibra subcellular localization and function in Drosophila Hippo signaling.

The Hippo pathway is an evolutionarily conserved regulator of tissue growth that integrates inputs from both polarity and actomyosin networks. An upstream activator of the Hippo pathway, Kibra, localizes at the junctional and medial regions of the apical cortex in epithelial cells, and medial accumulation promotes Kibra activity. Here, we demonstrate that cortical Kibra distribution is controlled by a tug-of-war between apical polarity and actomyosin dynamics.

Small GTPases modulate intrinsic and extrinsic forces that control epithelial folding in embryos.

Epithelial folding is a common means to execute morphogenetic movements. The gastrulating Drosophila embryo offers many examples of epithelial folding events, including the ventral, cephalic, and dorsal furrows. Each of these folding events is associated with changes in intracellular contractility and/or cytoskeleton structures that autonomously promote epithelial folding.

Rho1 activation recapitulates early gastrulation events in the ventral, but not dorsal, epithelium of embryos.

Ventral furrow formation, the first step in gastrulation, is a well-studied example of tissue morphogenesis. Rho1 is highly active in a subset of ventral cells and is required for this morphogenetic event. However, it is unclear whether spatially patterned Rho1 activity alone is sufficient to recapitulate all aspects of this morphogenetic event, including anisotropic apical constriction and coordinated cell movements.

Competition between kinesin-1 and myosin-V defines posterior determination.

Local accumulation of ) mRNA in the oocyte determines the posterior pole of the future embryo. Two major cytoskeletal components, microtubules and actin filaments, together with a microtubule motor, kinesin-1, and an actin motor, myosin-V, are essential for mRNA posterior localization. In this study, we use Staufen, an RNA-binding protein that colocalizes with mRNA, as a proxy for mRNA.

Drosophila muller f elements maintain a distinct set of genomic properties over 40 million years of evolution.

The Muller F element (4.2 Mb, ~80 protein-coding genes) is an unusual autosome of Drosophila melanogaster; it is mostly heterochromatic with a low recombination rate. To investigate how these properties impact the evolution of repeats and genes, we manually improved the sequence and annotated the genes on the D.