Centrosomes in Branching Morphogenesis

The centrosome, a major microtubule organizer, has important functions in regulating the cytoskeleton as well as the position of cellular structures and orientation of cells within tissues. The centrosome serves as the main cytoskeleton-organizing centre in the cell and is the classical site of microtubule nucleation and anchoring. For these reasons, centrosomes play a very important role in morphogenesis, not just in the early stages of cell divisions but also in the later stages of organogenesis. Many organs such as lung, kidney and blood vessels develop from epithelial tubes that branch into complex networks. Cells in the nervous system also form highly branched structures in order to build complex neuronal networks. During branching morphogenesis, cells have to rearrange within tissues though multicellular branching or through subcellular branching, also known as single-cell branching. For highly branched structures to be formed during embryonic development, the cytoskeleton needs to be extensively remodelled. The centrosome has been shown to play an important role during these events

17th Spanish Society for Developmental Biology Meeting: New Trends in Developmental Biology

The Spanish Society for Developmental Biology organized its 17th meeting in November 2020. The meeting, organized by CIC bioGUNE, the University of the Basque Country and the University of Cantabria, gathered about 280 registrants and received 132 scientific abstracts. Participants ranged from undergraduate to senior researchers, with a broad participation of Ph.D. students. The meeting was organized in 8 sessions: Growth and Scaling, Self-organization, Neurodevelopment, Genomes, Cell Biology, Development and Disease, Evo-Devo and Regeneration (Araújo et al., 2021). These sessions focused on the new tendencies in Developmental Biology research and, based on the science presented there, we organized this special issue on The 17th Edition of the Spanish Society for Developmental Biology Meeting: New Trends in Developmental Biology. This collection of articles gathers several scientific contributions in this area, featuring collaborative and interdisciplinary approaches among developmental biologists. With the focus on organogenesis and gene regulation, our selected content embraces novel discoveries on muscle development, regeneration and the transcriptional control and role of miRNAs in development, while highlighting advances in organogenesis and gonadal development

Coordinated crosstalk between microtubules and actin by a spectraplakin regulates lumen formation and branching

Subcellular lumen formation by single-cells involves complex cytoskeletal remodelling. We have previously shown that centrosomes are key players in the initiation of subcellular lumen formation in Drosophila melanogaster, but not much is known on the what leads to the growth of these subcellular luminal branches or makes them progress through a particular trajectory within the cytoplasm. Here, we have identified that the spectraplakin Short-stop (Shot) promotes the crosstalk between MTs and actin, which leads to the extension and guidance of the subcellular lumen within the Terminal Cell (TC) cytoplasm. Shot is enriched in cells undergoing the initial steps of subcellular branching as a direct response to FGF signalling. An excess of Shot induces ectopic acentrosomal luminal branching points in the embryonic and larval tracheal TC leading to cells with extra subcellular lumina. These data provide the first evidence for a role for spectraplakins in single-cell lumen formation and branching

Drosophila melanogaster Hedgehog cooperates with Frazzled to guide axons through a noncanonical signalling pathway

© 2015 Elsevier Ireland Ltd. We report that the morphogen Hedgehog (Hh) is an axonal chemoattractant in the midline of Drosophila melanogaster embryos. Hh is present in the ventral nerve cord during axonal guidance and overexpression of hh in the midline causes ectopic midline crossing of FasIIpositive axonal tracts. In addition, we show that Hh influences axonal guidance via a noncanonical signalling pathway dependent on Ptc. Our results reveal that the Hh pathway cooperates with the Netrin/Frazzled pathway to guide axons through the midline in invertebrates.E.B. was supported by a fellowship from the Spanish Ministerio de Ciencia y Innovación, D.R. was supported by the Eramus programme and a FPU fellowship (FPU 12/05765) and S.J.A. acknowledges a Ramon y Cajal Researcher position granted by the Spanish Ministerio de Ciencia y Innovación. This work was funded by the Spanish Ministerio de Ciencia y Innovación (RYC-2007-00417)Peer reviewe

Hedgehog is a positive regulator of FGF signalling during embryonic tracheal cell migration

Cell migration is a widespread and complex process that is crucial for morphogenesis and for the underlying invasion and metastasis of human cancers. During migration, cells are steered toward target sites by guidance molecules that induce cell direction and movement through complex intracellular mechanisms. The spatio-temporal regulation of the expression of these guidance molecules is of extreme importance for both normal morphogenesis and human disease. One way to achieve this precise regulation is by combinatorial inputs of different transcription factors. Here we used Drosophila melanogaster mutants with migration defects in the ganglionic branches of the tracheal system to further clarify guidance regulation during cell migration. By studying the cellular consequences of overactivated Hh signalling, using ptc mutants, we found that Hh positively regulates Bnl/FGF levels during embryonic stages. Our results show that Hh modulates cell migration non-autonomously in the tissues surrounding the action of its activity. We further demonstrate that the Hh signalling pathway regulates bnl expression via Stripe (Sr), a zinc-finger transcription factor with homology to the Early Growth Response (EGR) family of vertebrate transcription factors. We propose that Hh modulates embryonic cell migration by participating in the spatio-temporal regulation of bnl expression in a permissive mode. By doing so, we provide a molecular link between the activation of Hh signalling and increased chemotactic responses during cell migration

Displaced genital arch in a Drosophila melanogaster male

Drosophila melanogaster mutant ebony (e) is characterized by its pigmentation defects in the adult cuticle (Bridges and Morgan, 1923); eyegone (eyg) has been described as having head and eyes much smaller than normal (Ives, 1942); and the vestigial (vg) locus seems to be only involved in wing development (Bridges and Morgan, 1919). While analyzing the F1 offspring from the parental cross between the D. melanogaster strains e eyg and vg, a particular fly was observed. It was a male, with no extended wings and normal color (although slightly darker because it was heterozygote for e). Interestingly, its genital arch was displaced from its normal position. It was not located in the ventral tip of the abdomen, instead it was displaced almost 90 degrees towards the end of the abdomen (Figures 1 and 2). The abdominal area where the genital arch should be was covered with a thin tegument (Figures 3 and 4). Sex combs were properly located. The animal died by accident nine days after emerging and left no progeny (he was caught in the culture medium) [...]

Project management practices for collaborative university-industry R&D: a hybrid approach

This paper aims to help stakeholders involved in collaborative university-industry R&D initiatives by presenting a hybrid project management (PM) approach, with a set of key distinct PM practices for this particular context. Collaborative university-industry R&D initiatives are usually organized as programs with a set of related projects associated. Therefore, a hybrid PM approach was developed based on a case study research strategy. During the large case study analysis two research methods were applied: participant observation and document analysis. The hybrid management approach was developed based on the contingency theory, which identifies a set of 24 Must Have PM practices, and that are transversal to all projects in the program as the program governance must have to be assured. Additionally, it identifies three different sets of Nice to Have PM practices, which are optional and are dependent on the particular project context and PM approach adopted by each project team: waterfall or agile. Overall 32 Nice to Have PM practices were identified, being 15 of them agile, 3 waterfall and the 14 remaining transversal to both agile and waterfall approaches.This research is sponsored by the Portugal Incentive System for Research and Technological Development. Project in co-promotion nº 002814/2015 (iFACTORY 2015-2018) and by the FCT (SFRH/BPD/111033/2015)

Centrosome Amplification Increases Single-Cell Branching in Post-mitotic Cells

Centrosome amplification is a hallmark of cancer, although we are still far from understanding how this process affects tumorigenesis [1, 2]. Besides the contribution of supernumerary centrosomes to mitotic defects, their biological effects in the post-mitotic cell are not well known. Here, we exploit the effects of centrosome amplification in post-mitotic cells during single-cell branching. We show that Drosophila tracheal cells with extra centrosomes branch more than wild-type cells. We found that mutations in Rca1 and CycA affect subcellular branching, causing tracheal tip cells to form more than one subcellular lumen. We show that Rca1 and CycA post-mitotic cells have supernumerary centrosomes and that other mutant conditions that increase centrosome number also show excess of subcellular lumen branching. Furthermore, we show that de novo lumen formation is impaired in mutant embryos with fewer centrioles. The data presented here define a requirement for the centrosome as a microtubule-organizing center (MTOC) for the initiation of subcellular lumen formation. We propose that centrosomes are necessary to drive subcellular lumen formation. In addition, centrosome amplification increases single-cell branching, a process parallel to capillary sprouting in blood vessels [3]. These results shed new light on how centrosomes can contribute to pathology independently of mitotic defects

Tailor-made fluorinated ionic liquids for protein delivery

PTDC/QEQEPR/5841/2014 PTDC/QEQ-FTT/3289/2014 IF/00210/2014/CP1244/CT0003 UIDB/50006/2020Nowadays, pharmaceutical companies are facing several challenges with the development and approval of new biological products. The unique properties of several fluorinated ionic liquids (FILs), such as their high surfactant power in aqueous solutions, their chemical and biological stability, and low toxicity, favor their application in the pharmaceutical industry. Furthermore, the numerous combinations between cations and anions, in the FILs design, enlarge the possibilities to construct a successful delivery system. Several FILs also proved to not affect the activity, stability, and secondary structure of the therapeutic protein lysozyme. This work aims to study the aggregation behavior of distinct FILs in the protein suitable medium, in the presence or absence of lysozyme. Besides, different incubation conditions were tested to guarantee the optimal enzymatic activity of the protein at more stable delivery systems. Following the optimization of the incubation conditions, the quantification of the encapsulated lysozyme was performed to evaluate the encapsulation efficiency of each FIL-based system. The release of the protein was tested applying variables such as time, temperature, and ultrasound frequency. The experimental results suggest that the aggregation behavior of FILs is not significantly influenced by the protein and/or protein buffer and supports their application for the design of delivery systems with high encapsulation efficiencies, maintaining the biological activity of either encapsulated and released protein.publishersversionpublishe

A feedback mechanism converts individual cell features into a supracellular ECM structure in Drosophila trachea

The extracellular matrix (ECM), a structure contributed to and commonly shared by many cells in an organism, plays an active role during morphogenesis. Here, we used the Drosophila tracheal system to study the complex relationship between the ECM and epithelial cells during development. We show that there is an active feedback mechanism between the apical ECM (aECM) and the apical F-actin in tracheal cells. Furthermore, we reveal that cell-cell junctions are key players in this aECM patterning and organisation and that individual cells contribute autonomously to their aECM. Strikingly, changes in the aECM influence the levels of phosphorylated Src42A (pSrc) at cell junctions. Therefore, we propose that Src42A phosphorylation levels provide a link for the ECM environment to ensure proper cytoskeletal organisation