Orbit(ing) the furrow

Orbit(ing) the furrow

alcium just got a promotion. Findings by Caroppo et al. (page 111) reveal that in addition to its many roles inside the cell, Ca 2 ϩ has a distinct extracellular purpose: it acts via a Ca 2 ϩ receptor (CaR) to regulate the function of gastric epithelial cells. It has been known for some time that extracellular Ca 2 ϩ can be sensed by the CaR. The team noted that a Ca 2 ϩ gradient was generated ...

Regulators of the morphogenetic furrow.

Vesicles and actin are targeted to the cleavage furrow via furrow microtubules and the central spindle

During cytokinesis, cleavage furrow invagination requires an actomyosin-based contractile ring and addition of new membrane. Little is known about how this actin and membrane traffic to the cleavage furrow. We address this through live analysis of fluorescently tagged vesicles in postcellularized Drosophila melanogaster embryos. We find that during cytokinesis, F-actin and membrane are targeted...

RhoA controls furrow formation

vidence that the cytokinetic apparatus is dependent on spindle microtubules comes primarily from classical experiments in which the spindle was manually moved or disrupted. On page 91, Bement et al. reveal the physiology that underlies these findings. Active RhoA localizes to a narrow zone at the site of future furrow formation in a microtubule-dependent manner, and the RhoA zone moves in respo...

Linking spindle to furrow

olarizing cells must first pick a direction. The external cues that guide this choice are obvious: bud scars or mating partners for budding yeast, and chemoattractant gradients for Dictyostelium and neutrophils. But polarization still occurs, albeit in a random direction, when these cues are either removed or made uniform. Now, Roland Wedlich-Soldner, Rong Li (Harvard Medical School, Boston, MA...