In Drosophila, blood development occurs in a specialized larval hematopoietic organ, the lymph gland (LG), within which stem-like hemocyte precursors or prohemocytes differentiate to multiple blood cell types. Here we show that components of the Wingless (Wg) signaling pathway are expressed in prohemocytes. Loss- and gain-of-function analysis indicates that canonical Wg signaling is required fo...

At vertebrate neuromuscular junctions (NMJs), Agrin plays pivotal roles in synapse development, but molecules that activate synapse formation at central synapses are largely unknown. Members of the Wnt family are well established as morphogens, yet recently they have also been implicated in synapse maturation. Here we demonstrate that the Drosophila Wnt, Wingless (Wg), is essential for synapse ...

Wingless (Wg)/Wnt signaling is conserved in all metazoan animals and plays critical roles in development. The Wg/Wnt morphogen reception is essential for signal activation, whose activity is mediated through the receptor complex and a scaffold protein Dishevelled (Dsh). We report here that the exon junction complex (EJC) activity is indispensable for Wg signaling by maintaining an appropriate l...

Synapse formation is fundamental to the development and function of the brain, and it is thought to be of central importance in learning and memory. Assembly of synapses requires coordination between the neurotransmitter-releasing presynaptic neuron and the signal-receiving postsynaptic cell. In recent years, major advances have shown how presynaptic and postsynaptic components interact during ...

PURPOSE In Feb 2015 an image of a dress posted on Tumblr triggered an internet phenomenon: Is the Dress blue and black (BB) or white and gold (WG)? Many claim BB and others insist WG while the true colors are BB. The prevailing theory is that assumptions about the illuminant govern perception of the Dress with WG due to bluish lighting and BB due to yellowish. Our purpose was to determine if ea...

Early Warning Systems aim at detecting unclassified but potentially harmful system behavior based on preliminary indications and are complementary to Intrusion Detection Systems. Both kinds of systems try to detect, identify and react before possible damage occurs and contribute to an integrated and aggregated situation report (big picture). A particular emphasis of Early Warning Systems is to ...

The ability to regenerate following stress is a hallmark of self-renewing tissues. However, little is known about how regeneration differs from homeostatic tissue maintenance. Here, we study the role and regulation of Wingless (Wg)/Wnt signalling during intestinal regeneration using the Drosophila adult midgut. We show that Wg is produced by the intestinal epithelial compartment upon damage or ...

The Frizzled (Fz) receptors contain seven transmembrane helices and an amino-terminal cysteine-rich domain (CRD) that is sufficient and necessary for binding of the ligands, the Wnts. Recent genetic experiments have suggested, however, that the CRD is dispensable for signaling. We engineered fz CRD mutant transgenes and tested them for Wg signaling activity. None of the mutants was functional i...

The Drosophila wing imaginal disc gives rise to three body parts along the proximo-distal (P-D) axis: the wing blade, the wing hinge and the mesonotum. Development of the wing blade initiates along part of the dorsal/ventral (D/V) compartment boundary and requires input from both the Notch and wingless (wg) signal transduction pathways. In the wing blade, wg activates the gene vestigial (vg), w...

Background: The presence of anti-neutrophil cytoplasmic antibodies (ANCA) in Wegener’s granulomatosis (WG), implicate the neutrophil as a key effector cell. Previous studies have reported elevated neutrophil counts in the lung although the determinants of neutrophil chemotaxis in the WG lung are unknown. Methods: BALF cell counts, myeloperoxidase (MPO) and chemokines were measured in 27 patient...