Superresolution microscopy reveals actomyosin dynamics in medioapical arrays.

Arrays of actin filaments (F-actin) near the apical surface of epithelial cells (medioapical arrays) contribute to apical constriction and morphogenesis throughout phylogeny. Here, superresolution approaches (grazing incidence structured illumination, GI-SIM, and lattice light sheet, LLSM) microscopy resolve individual, fluorescently labeled F-actin and bipolar myosin filaments that drive amnioserosa cell shape changes during dorsal closure in . In expanded cells, F-actin and myosin form loose, apically domed meshworks at the plasma membrane.

A multi-functional microfluidic device compatible with widefield and light sheet microscopy.

We present a microfluidic device compatible with high resolution light sheet and super-resolution microscopy. The device is a 150 μm thick chamber with a transparent fluorinated ethylene propylene (FEP) cover that has a similar refractive index (1.34) to water (1.

Identifying Key Genetic Regions for Cell Sheet Morphogenesis on Chromosome 2L Using a Deficiency Screen in Dorsal Closure.

Cell sheet morphogenesis is essential for metazoan development and homeostasis of animal form - it contributes to developmental milestones including gastrulation, neural tube closure, heart and palate formation and to tissue maintenance during wound healing. Dorsal closure, a well-characterized stage in embryogenesis and a model for cell sheet morphogenesis, is a remarkably robust process during which coordination of conserved gene expression patterns and signaling cascades regulate the cellular shape changes and movements. New 'dorsal closure genes' continue to be discovered due to advances in imaging and genetics.

Visualizing Intracellular Organelle and Cytoskeletal Interactions at Nanoscale Resolution on Millisecond Timescales.

In eukaryotic cells, organelles and the cytoskeleton undergo highly dynamic yet organized interactions capable of orchestrating complex cellular functions. Visualizing these interactions requires noninvasive, long-duration imaging of the intracellular environment at high spatiotemporal resolution and low background. To achieve these normally opposing goals, we developed grazing incidence structured illumination microscopy (GI-SIM) that is capable of imaging dynamic events near the basal cell cortex at 97-nm resolution and 266 frames/s over thousands of time points.

Identifying Genetic Players in Cell Sheet Morphogenesis Using a Deficiency Screen for Genes on Chromosome 2R Involved in Dorsal Closure.

Cell sheet morphogenesis characterizes key developmental transitions and homeostasis, in vertebrates and throughout phylogeny, including gastrulation, neural tube formation and wound healing. Dorsal closure, a process during embryogenesis, has emerged as a model for cell sheet morphogenesis. ∼140 genes are currently known to affect dorsal closure and new genes are identified each year.

MRCK-1 Drives Apical Constriction in C. elegans by Linking Developmental Patterning to Force Generation.

Apical constriction is a change in cell shape that drives key morphogenetic events including gastrulation and neural tube formation. Apical force-producing actomyosin networks drive apical constriction by contracting while connected to cell-cell junctions. The mechanisms by which developmental patterning regulates these actomyosin networks and associated junctions with spatial precision are not fully understood.