Differentiation of the embryonic termini in Drosophila depends on signaling by Tor RTK, which induces terminal gene expression inactivating at poles a uniformly distributed repressor activity that involves Gro corepressor. Here, we identify new gene, cic , acts as genes regulated pathway. also mediates repression along dorsoventral axis, process requires Dorsal morphogen and Gro, is inhibited termini. encodes an HMG-box transcription factor interacts with vitro. We present evidence regulates...

The subdivision of the Drosophila body into distinct terminal and central domains depends on torso (tor) protein, a putative receptor tyrosine kinase that is active at both ends early embryo. We show tor protein uniformly expressed along surface membrane embryos despite its localized activity poles. Further, we present evidence polarized this other gene functions, one which may be extracellular ligand generated during oogenesis. Finally, using temperature-sensitive gain-of-function mutation...

Metastasis underlies the majority of cancer-related deaths yet remains poorly understood due, in part, to lack models vivo. Here we show that expression EMT master inducer Snail primary adult Drosophila intestinal tumors leads dissemination tumor cells and formation macrometastases. drives an cells, which, although retaining some epithelial markers, subsequently break through basal lamina midgut, undergo a collective migration seed polyclonal metastases. While metastases re-epithelialize...

By using a hsp70-Ubx fusion gene, we have ectopically expressed Ubx product in the embryonic head primordia and studied developmental effects on larval head. We find that after high persistent levels of product, is replaced by three (C1, C2 C3) abdominal-like denticle belts. The C3 belts are homeotic transformations parasegments 1 2, respectively, while C1 belt probably derives from transformation subsequent most anterior procephalic primordia. On basis their response to other arguments,...

Body size in holometabolous insects is determined by the at which juvenile larva undergoes metamorphosis to pupal stage. To undergo larva-pupa transition, must reach a critical developmental checkpoint, threshold (TS); however, molecular mechanisms through TS cues this transition remain be fully characterized. Here, we use flour beetle Tribolium castaneum characterize underlying entry into metamorphosis. We found that T. reaches beginning of last larval instar, associated with downregulation...

The extracellular matrix (ECM), a structure contributed to and commonly shared by many cells in an organism, plays active role during morphogenesis. Here, we used the Drosophila tracheal system study complex relationship between ECM epithelial development. We show that there is feedback mechanism apical (aECM) F-actin cells. Furthermore, reveal cell-cell junctions are key players this aECM patterning organisation individual contribute autonomously their aECM. Strikingly, changes influence...

Organ morphogenesis requires the coordinated activity of many mechanisms involved in cell rearrangements, size control, proliferation and organ integrity. Here we report that Lachesin (Lac), a surface protein, is required for proper Drosophila tracheal system. Homozygous embryos Lac mutations, which find fail to complement previous identified bulbous (bulb) mutation, display convoluted tubes tube breaks. At cellular level, can detect enlarged cells, suggesting regulates by influencing length...

The ventral veinless gene (vvl) encodes the previously identified Cf1a protein, a transcription factor containing POU-domain. During embryonic development vvl function is required for formation of tracheal tree and in patterning ectoderm. imaginal cell proliferation differentiation wing veins. expression restricted to regions where its required, dependent on coordinate activities signalling molecules such as decapentaplegic, wingless hedgehog. interacts with other genes involved vein...

The specification of the most anterior and posterior domains Drosophila embryo depends on activity torso protein, a putative tyrosine kinase receptor. Localized at poles generates graded information that specifies distinct portions body. primary response to terminal signal in end is likely be activation gap genes huckebein tailless. Here I address question how maternal different elements pattern what role tailless activities may play this process. These experiments show distinctly localized...

A major issue in morphogenesis is to understand how the activity of genes specifying cell fate affects cytoskeletal components that modify shape and induce movements. Here, we approach this question by investigating a group cells from an epithelial sheet initiate invagination ultimately form Drosophila tracheal tubes. We describe behavior at show it associated with, requires, distinct recruitment Myosin II apical surface invaginating edge. process achieved crossveinless-c , gene coding for...

The transcriptional repressor Capicua (Cic) controls multiple aspects of Drosophila embryogenesis and has been implicated in vertebrate development human diseases. Receptor tyrosine kinases (RTKs) can antagonize Cic-dependent gene repression, but the mechanisms responsible for this effect are not fully understood. Based on genetic imaging studies early embryo, we found that Torso RTK signaling increase rate Cic degradation by changing its subcellular localization. We propose is degraded...

Whereas the series of genetic events leading to colorectal cancer (CRC) have been well established, precise functions that these alterations play in tumor progression and how they disrupt intestinal homeostasis remain poorly characterized. Activation Wnt/Wg signaling pathway by a mutation gene APC is most common trigger for CRC, inducing benign lesions progress carcinomas due accumulation other alterations. Among those, Ras mutations drive tumour as epithelial cancers. As mammalian...