biosights: March 16, 2015 - PAPC separates tissues at a Snail's pace

submitted by: JCB
Brachet's cleft separates the ectoderm and mesoderm of early Xenopus and zebrafish embryos. Luu et al. reveal that, in conjunction with the transcription factor Snail1, the protocadherin PAPC promotes tissue separation by down-regulating planar cell polarity proteins at the ectoderm-mesoderm boundary. This biosights episode presents the paper by Luu et al. from the March 16, 2015, issue of The Journal of Cell Biology and includes an interview with one of the paper's senior authors, Rudolf...

biosights: February 16, 2015 - Filopodia point the way for haptotaxis

submitted by: JCB
Migrating fibroblasts maintain or change their direction by branching off new lamellipodia from existing protrusions at the cell's leading edge. Johnson et al. reveal that filopodial protrusions initiate and orient these lamellipodia, helping fibroblasts navigate gradients of immobilized guidance cues. This biosights episode presents the paper by Johnson et al. from the February 16, 2015, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Jason...

biosights: January 19, 2015 - Tubulin transport pumps up cilia

submitted by: JCB
The assembly of cilia and flagella requires the delivery of large amounts of tubulin to the growing ends of the organelles' microtubules. Craft et al. reveal that tubulin loading onto intraflagellar transport particles is specifically upregulated in growing cilia. This biosights episode presents the paper by Craft et al. from the January 19, 2015, issue of The Journal of Cell Biology and includes an interview with the paper's senior author, Karl Lechtreck (University of Georgia, Athens, GA)....

biosights: December 22, 2014 - Osmotic gradient is just the tonic for wounded epithelia

submitted by: JCB
Rapid wound repair is generally thought to be initiated by intrinsic cues, such as changes in the structure or mechanics of damaged tissues. Gault et al. reveal that an extrinsic signal — the osmolarity of the external environment — can stimulate wound closure in zebrafish by inducing epithelial cell migration. This biosights episode presents the paper by Gault et al. from the December 22, 2014, issue of The Journal of Cell Biology and includes an interview with the paper's senior...

biosights: November 24, 2014 - Dynein helps centrioles stick together

submitted by: JCB
Dynein has numerous functions in mitosis, but the function of the motor complex's light intermediate chains is poorly understood. Jones et al. reveal that dynein's light intermediate chains are required to maintain centrosome integrity during mitosis, preventing the premature separation of mother-daughter centrioles and the formation of multipolar spindles. This biosights episode presents the paper by Jones et al. from the November 24, 2014, issue of The Journal of Cell Biology and includes...

biosights: October 27, 2014 - Epithelial cells make changes at the top

submitted by: JCB
The apical surfaces of polarized epithelia are covered by short, actin-rich protrusions called microvilli, but what happens to these structures when cells detach from a monolayer during development or disease is unclear. Klingner et al. reveal that non-confluent epithelial cells form longer, more dynamic microvilli on their apical surface that connect to a cortical actomyosin network. This biosights episode presents the paper by Klingner et al. from the October 13, 2014, issue of The Journal...

biosights: September 29, 2014 - Cdc42 prompts a change of heart

submitted by: JCB
The Drosophila heart is a simple tubular structure with a central lumen. Vogler et al. reveal that the small GTPase Cdc42 and actin-nucleating formin proteins promote lumen formation by regulating the dynamics of non-muscle myosin in cardioblasts during heart morphogenesis. This biosights episode presents the paper by Vogler et al. from the September 29, 2014, issue of The Journal of Cell Biology and includes an interview with two of the paper's authors, Georg Vogler and Rolf Bodmer...

biosights: September 1, 2014 - Deploying exosomes in a battle of the sexes

submitted by: JCB
The paired accessory glands of male Drosophila secrete multiple signaling factors into the seminal fluid that promote reproductive success by altering the recipient female's physiology and behavior. Corrigan et al. reveal that the secondary cells of accessory glands secrete membrane-bound exosomes in a BMP-dependent manner that, after being transferred into the female reproductive tract, inhibit the female's inclination to re-mate with other male flies. This biosights episode presents the...

biosights: August 4, 2014 - Rok keeps its finger on the pulse of apical constriction

submitted by: JCB
Early in Drosophila embryogenesis, contractile pulses of myosin assembly and disassembly constrict the apical domains of a group of epithelial cells to drive their invagination into a ventral furrow. Vasquez et al. reveal that Rho kinase and myosin phosphatase dynamically regulate these myosin pulses and that the stepwise constriction resulting from this helps maintain tissue integrity during epithelial invagination. This biosights episode presents the paper by Vasquez et al. from the August...

biosights: July 7, 2014 - The fluid dynamics of collective cell migration

submitted by: JCB
During development and tumor metastasis, cells prepare to migrate by undergoing an epithelial-to-mesenchymal transition that loosens their connections to neighboring cells. But some cell types then migrate en masse to their final destinations, indicating that their intercellular adhesions aren't disrupted completely. Kuriyama et al. reveal that the phospholipid lysophosphatidic acid promotes the collective migration of Xenopus neural crest cells by downregulating the surface expression of...