Wnt and Src signals converge on YAP-TEAD to drive intestinal regeneration.

Wnt signalling induces a gradient of stem/progenitor cell proliferation along the crypt-villus axis of the intestine, which becomes expanded during intestinal regeneration or tumour formation. The YAP transcriptional co-activator is known to be required for intestinal regeneration, but its mode of regulation remains controversial. Here we show that the YAP-TEAD transcription factor is a key downstream effector of Wnt signalling in the intestine.

Mechanobiology: Forging a strong matrix at tendons.

Nature faces the challenge of stably attaching soft muscles to a stiff skeleton. A new study combines live imaging and fly genetics to reveal that mechanical tension and a putative intracellular chaperone assist in assembling the gigantic extracellular matrix protein Dumpy at fly tendon-skeleton interfaces.

Rho-Kinase Planar Polarization at Tissue Boundaries Depends on Phospho-regulation of Membrane Residence Time.

The myosin II activator Rho-kinase (Rok) is planar polarized at the tissue boundary of the Drosophila embryonic salivary gland placode through a negative regulation by the apical polarity protein Crumbs that is anisotropically localized at the boundary. However, in inner cells of the placode, both Crumbs and Rok are isotropically enriched at junctions. We propose that modulation of Rok membrane residence time by Crumbs' downstream effectors can reconcile both behaviors.

Mask family proteins ANKHD1 and ANKRD17 regulate YAP nuclear import and stability.

Mask family proteins were discovered in to promote the activity of the transcriptional coactivator Yorkie (Yki), the sole fly homolog of mammalian YAP (YAP1) and TAZ (WWTR1). The molecular function of Mask, or its mammalian homologs Mask1 (ANKHD1) and Mask2 (ANKRD17), remains unclear. Mask family proteins contain two ankyrin repeat domains that bind Yki/YAP as well as a conserved nuclear localisation sequence (NLS) and nuclear export sequence (NES), suggesting a role in nucleo-cytoplasmic transport.

Squeezing out in a "tug of war": The role of myosin in neural stem cell delamination.

Neural stem cells or neuroblasts in the embryo delaminate as single cells from the embryonic epidermis to give rise to the nervous system. Using this accessible system to examine the molecular mechanisms of cell ingression at a high temporal and spatial resolution, in this issue, Simões et al. (2017.

Mask proteins are cofactors of Yorkie/YAP in the Hippo pathway.

The Hippo signaling pathway acts via the Yorkie (Yki)/Yes-associated protein (YAP) transcriptional coactivator family to control tissue growth in both Drosophila and mammals [1-3]. Yki/YAP drives tissue growth by activating target gene transcription, but how it does so remains unclear. Here we identify Mask as a novel cofactor for Yki/YAP.

Live-imaging of single stem cells within their niche reveals that a U3snoRNP component segregates asymmetrically and is required for self-renewal in Drosophila.

Stem cells generate self-renewing and differentiating progeny over many rounds of asymmetric divisions. How stem cell growth rate and size are maintained over time remains unknown. We isolated mutations in a Drosophila melanogaster gene, wicked (wcd), which induce premature differentiation of germline stem cells (GSCs).

Telomeric trans-silencing: an epigenetic repression combining RNA silencing and heterochromatin formation.

The study of P-element repression in Drosophila melanogaster led to the discovery of the telomeric Trans-Silencing Effect (TSE), a repression mechanism by which a transposon or a transgene inserted in subtelomeric heterochromatin (Telomeric Associated Sequence or TAS) has the capacity to repress in trans in the female germline, a homologous transposon, or transgene located in euchromatin. TSE shows variegation among egg chambers in ovaries when silencing is incomplete. Here, we report that TSE displays an epigenetic transmission through meiosis, which involves an extrachromosomal maternally transmitted factor.