Non-autonomous insulin signaling delays mitotic progression in C. elegans germline stem and progenitor cells.

Stem and progenitor cell mitosis is essential for tissue development and homeostasis. How these cells ensure proper chromosome segregation, and thereby maintain mitotic fidelity, in the complex physiological environment of a living animal is poorly understood. Here we use in situ live-cell imaging of C.

Uncoupling cell division and cytokinesis during germline development in metazoans.

The canonical eukaryotic cell cycle ends with cytokinesis, which physically divides the mother cell in two and allows the cycle to resume in the newly individualized daughter cells. However, during germline development in nearly all metazoans, dividing germ cells undergo incomplete cytokinesis and germ cells stay connected by intercellular bridges which allow the exchange of cytoplasm and organelles between cells. The near ubiquity of incomplete cytokinesis in animal germ lines suggests that this is an ancient feature that is fundamental for the development and function of this tissue.

Live-cell Imaging and Analysis of Germline Stem Cell Mitosis in .

Model organisms offer the opportunity to decipher the dynamic and complex behavior of stem cells in their native environment; however, imaging stem cells remains technically challenging. germline stem cells (GSCs) are distinctly accessible for live imaging but relatively few studies have taken advantage of this potential. Here we provide our protocol for mounting and live imaging dividing GSCs, as well as analysis tools to facilitate the processing of large datasets.

CentTracker: a trainable, machine-learning-based tool for large-scale analyses of germline stem cell mitosis.

Investigating the complex interactions between stem cells and their native environment requires an efficient means to image them in situ. germline stem cells (GSCs) are distinctly accessible for intravital imaging; however, long-term image acquisition and analysis of dividing GSCs can be technically challenging. Here we present a systematic investigation into the technical factors impacting GSC physiology during live imaging and provide an optimized method for monitoring GSC mitosis under minimally disruptive conditions.

Widely Used Mutants of , Encoding the Tumor Necrosis Factor, Carry Additional Mutations in the NimrodC1 Phagocytosis Receptor.

The process of apoptosis in epithelia involves activation of caspases, delamination of cells, and degradation of cellular components. Corpses and cellular debris are then rapidly cleared from the tissue by phagocytic blood cells. In studies of the TNF, Eiger (Egr) and cell death in wing imaginal discs, the epithelial primordia of fly wings, we noticed that dying cells appeared to transiently accumulate in mutant wing discs, raising the possibility that their phagocytic engulfment by hemocytes was impaired.

Spindle assembly checkpoint strength is linked to cell fate in the Caenorhabditis elegans embryo.

The spindle assembly checkpoint (SAC) is a conserved mitotic regulator that preserves genome stability by monitoring kinetochore-microtubule attachments and blocking anaphase onset until chromosome biorientation is achieved. Despite its central role in maintaining mitotic fidelity, the ability of the SAC to delay mitotic exit in the presence of kinetochore-microtubule attachment defects (SAC "strength") appears to vary widely. How different cellular aspects drive this variation remains largely unknown.

Bigger Isn't Always Better: Cell Size and the Spindle Assembly Checkpoint.

Variation in the activity of the spindle assembly checkpoint has been observed in different cell types, yet the reason for this variability remains poorly understood. Reporting in Developmental Cell, Galli and Morgan (2016) show that checkpoint activity increases during development as cell size, and the cytoplasm-to-kinetochore ratio, decreases.

Investigating the regulation of stem and progenitor cell mitotic progression by in situ imaging.

Genome stability relies upon efficacious chromosome congression and regulation by the spindle assembly checkpoint (SAC). The study of these fundamental mitotic processes in adult stem and progenitor cells has been limited by the technical challenge of imaging mitosis in these cells in situ. Notably, how broader physiological changes, such as dietary intake or age, affect mitotic progression in stem and/or progenitor cells is largely unknown.

Identification and characterization of genes required for compensatory growth in Drosophila.

To maintain tissue homeostasis, some organs are able to replace dying cells with additional proliferation of surviving cells. Such proliferation can be localized (e.g.