Proper spatial and temporal localization of specific mRNAs is pivotal in the early stages of development. To dissect the mechanisms of localization, several groups are employing advanced fluorescence microscopy to track RNA movements in live oocytes and embryos.
Pre-mRNA splicing is required for the accurate expression of virtually all human protein coding genes. However, splicing also plays important roles in coordinating subsequent steps of pre-mRNA processing such as polyadenylation and mRNA export. Here, we test the hypothesis that nuclear pre-mRNA processing influences the polyribosome association of ...
Formation of heterochromatin serves a critical role in organizing the genome and regulating gene expression. In most organisms, heterochromatin flanks centromeres and telomeres. To identify heterochromatic regions in the heavily studied model C. elegans, which possesses holocentric chromosomes with dispersed centromeres, we analyzed the genome-wide...
Caenorhabditis elegans zygotes undergo a series of four differentiative divisions to generate 5 somatic founder cells and a germ-line progenitor cell by the 16- to 24-cell stage of embryogenesis. The pattern of divisions, cell positions, and development of the embryonic cells are invariant from embryo to embryo. Through a combination of embryo mani...
Germ-line granules in C. elegans embryos (P granules) can be visualized by immunofluorescence microscopy using a monoclonal antibody. In mutant zygotes with abnormal spindle orientations and in wild-type zygotes treated with the microtubule inhibitors nocodazole, colcemid, vinblastine, and griseofulvin, both P-granule segregation to the posterior p...
To address questions about mechanisms of filament-based organelle transport, a system was developed to image and track mitochondria in an intact Drosophila nervous system. Mutant analyses suggest that the primary motors for mitochondrial movement in larval motor axons are kinesin-1 (anterograde) and cytoplasmic dynein (retrograde), and interestingl...
Specific bone marrow (BM) niches are critical for hematopoietic stem cell (HSC) function during both normal hematopoiesis and in stem cell transplantation therapy. We demonstrate that the guidance molecule Robo4 functions to specifically anchor HSCs to BM niches. Robo4-deficient HSCs displayed poor localization to BM niches and drastically reduced ...
In the field of breast biology, there is a growing appreciation for the "gatekeeping function" of basal cells during development and disease processes yet mechanisms regulating the generation of these cells are poorly understood. Here, we report that the proliferation of basal cells is controlled by SLIT/ROBO1 signaling and that production of these...
To optimize the biological activity of pyrrole-imidazole polyamide DNA-binding molecules, we characterized the aggregation propensity of these compounds through dynamic light scattering and fractional solubility analysis. Nearly all studied polyamides were found to form measurable particles 50-500 nm in size under biologically relevant conditions, ...