Identifying loci required for follicular patterning using directed mosaics

We have developed a ‘directed mosaic’ system in Drosophila by using the GAL4 system to control the expression of the yeast recombinase, FLP, in a spatial and temporal fashion. By directing FLP expression, we show that it is possible to efficiently and specifically target loss-of-function studies for vital loci to the developmental pathway of interest. A simple F1 adult phenotypic screen demonstrated that most adult tissues can be analyzed with this approach. Using GAL4 lines expressed during oogenesis, we have refined the system to examine the roles of vital loci in the development of the follicular epithelium. We have identified essential genes involved in egg chamber organization, cell migration and cell shape. Further, we have used this technique to gain insights into the role of the Drosophila EGF receptor pathway in establishing the egg axes. Finally, using different UAS-FLP, GAL4 and existing FRT lines, we have built stocks that permit the analysis of approximately 95% of the genome in follicular mosaics.

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Role of the EGF receptor pathway in growth and patterning of the Drosophila wing through the regulation of vestigial

Development ◽

10.1242/dev.126.5.975 ◽

1999 ◽

Vol 126 (5) ◽

pp. 975-985 ◽

Cited By ~ 6

Author(s):

R. Nagaraj ◽

A.T. Pickup ◽

R. Howes ◽

K. Moses ◽

M. Freeman ◽

...

Keyword(s):

Egf Receptor ◽

Regulatory Gene ◽

Ectopic Expression ◽

Wing Disc ◽

Loss Of Function ◽

Drosophila Wing ◽

Expression Studies ◽

Coordinated Expression ◽

Wing Pouch

Growth and patterning of the Drosophila wing disc depends on the coordinated expression of the key regulatory gene vestigial both in the Dorsal-Ventral (D/V) boundary cells and in the wing pouch. We propose that a short-range signal originating from the core of the D/V boundary cells is responsible for activating EGFR in a zone of organizing cells on the edges of the D/V boundary. Using loss-of-function mutations and ectopic expression studies, we show that EGFR signaling is essential for vestigial transcription in these cells and for making them competent to undergo subsequent vestigial-mediated proliferation within the wing pouch.

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CYFIP2 containing WAVE complexes inhibit cell migration

10.1101/2020.07.02.184655 ◽

2020 ◽

Author(s):

Anna Polesskaya ◽

Arthur Boutillon ◽

Yanan Wang ◽

Marc Lavielle ◽

Sophie Vacher ◽

...

Keyword(s):

Cell Migration ◽

Mammary Epithelial Cells ◽

Leading Edge ◽

Good Prognosis ◽

Mammary Epithelial ◽

Breast Cancer Patients ◽

Loss Of Function ◽

A Cell ◽

Wave Complex

ABSTRACTBranched actin networks polymerized by the Arp2/3 complex are critical for cell migration. The WAVE complex is the major Arp2/3 activator at the leading edge of migrating cells. However, multiple distinct WAVE complexes can be assembled in a cell, due to the combinatorial complexity of paralogous subunits. When systematically analyzing the contribution of each WAVE complex subunit to the metastasis-free survival of breast cancer patients, we found that overexpression of the CYFIP2 subunit was surprisingly associated with good prognosis. Gain and loss of function experiments in transformed and untransformed mammary epithelial cells revealed that cell migration was always inversely related to CYFIP2 levels. The role of CYFIP2 was systematically opposite to the role of the paralogous subunit CYFIP1 or of the NCKAP1 subunit. The specific CYFIP2 function in inhibiting cell migration was related to its unique ability to down-regulate classical pro-migratory WAVE complexes. The anti-migratory function of CYFIP2 was also revealed in migration of prechordal plate cells during gastrulation of the zebrafish embryo, indicating that the unique function of CYFIP2 is critically important in both physiological and pathophysiological migrations.

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Hedgehog signaling patterns the tracheal branches

Development ◽

10.1242/dev.128.9.1599 ◽

2001 ◽

Vol 128 (9) ◽

pp. 1599-1606 ◽

Cited By ~ 1

Author(s):

L. Glazer ◽

B.Z. Shilo

Keyword(s):

Cell Migration ◽

Hedgehog Signaling ◽

Egf Receptor ◽

Cell Types ◽

Fixed Number ◽

Branching Pattern ◽

Tracheal System ◽

Tracheal Cell ◽

Distinct Cell

The elaborate branching pattern of the Drosophila tracheal system originates from ten tracheal placodes on both sides of the embryo, each consisting of about 80 cells. Simultaneous cell migration from each tracheal pit in six different directions gives rise to the stereotyped branching pattern. Each branch contains a fixed number of cells. Previous work has shown that in the dorsoventral axis, localized activation of the Dpp, Wnt and EGF receptor (DER) pathways, subdivides the tracheal pit into distinct domains. We present the role of the Hedgehog (Hh) signaling system in patterning the tracheal branches. Hh is expressed in segmental stripes abutting the anterior border of the tracheal placodes. Induction of patched expression, which results from activation by Hh, demonstrates that cells in the anterior half of the tracheal pit are activated. In hh-mutant embryos migration of all tracheal branches is absent or stalled. These defects arise from a direct effect of Hh on tracheal cells, rather than by indirect effects on patterning of the ectoderm. Tracheal cell migration could be rescued by expressing Hh only in the tracheal cells, without rescuing the ectodermal defects. Signaling by several pathways, including the Hh pathway, thus serves to subdivide the uniform population of tracheal cells into distinct cell types that will subsequently be recruited into the different branches.

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The role of integrins in Drosophila egg chamber morphogenesis

10.1101/706069 ◽

2019 ◽

Author(s):

Holly E. Lovegrove ◽

Dan T. Bergstralh ◽

Daniel St Johnston

Keyword(s):

Basement Membrane ◽

Cell Polarity ◽

Cell Shape ◽

Follicle Cell ◽

Follicle Cells ◽

Follicular Epithelium ◽

Egg Chambers ◽

Germline Cyst ◽

Egg Chamber

AbstractA Drosophila egg chamber is comprised of a germline cyst surrounded by a tightly-organised epithelial monolayer, the follicular epithelium (FE). Loss of integrin function from the FE disrupts epithelial organisation at egg chamber termini, but the cause of this phenotype remains unclear. Here we show that the β-integrin Myospheroid (Mys) is only required during early oogenesis when the pre-follicle cells form the FE. mys mutants disrupt both the formation of a monolayered epithelium at egg chamber termini and the morphogenesis of the stalk between adjacent egg chambers, which develops through the intercalation of two rows of cells into a single-cell wide stalk. Secondary epithelia, like the FE, have been proposed to require adhesion to the basement membrane to polarise. However, Mys is not required for pre-follicle cell polarisation, as both follicle and stalk cells localise polarity factors correctly, despite being mispositioned. Instead, loss of integrins causes pre-follicle cells to basally constrict, detach from the basement membrane and become internalised. Thus, integrin function is dispensable for pre-follicle cell polarity but is required to maintain cellular organisation and cell shape during morphogenesis.

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The Tubulin Code and Tubulin-Modifying Enzymes in Autophagy and Cancer

Cancers ◽

10.3390/cancers14010006 ◽

2021 ◽

Vol 14 (1) ◽

pp. 6

Author(s):

Daniela Trisciuoglio ◽

Francesca Degrassi

Keyword(s):

Cell Migration ◽

Cell Shape ◽

Therapy Resistance ◽

Degradation Pathway ◽

Eukaryotic Cells ◽

Cancer Growth ◽

Cell Functions ◽

Intracellular Movement ◽

Autophagic Process

Microtubules are tubulin polymers that constitute the structure of eukaryotic cells. They control different cell functions that are often deregulated in cancer, such as cell shape, cell motility and the intracellular movement of organelles. Here, we focus on the crucial role of tubulin modifications in determining different cancer characteristics, including metastatic cell migration and therapy resistance. We also discuss the influence of microtubule modifications on the autophagic process—the cellular degradation pathway that influences cancer growth. We discuss findings showing that inducing microtubule modifications can be used as a means to kill cancer cells by inhibiting autophagy.

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The role of DUBs in the post-translational control of cell migration

Essays in Biochemistry ◽

10.1042/ebc20190022 ◽

2019 ◽

Vol 63 (5) ◽

pp. 579-594 ◽

Cited By ~ 2

Author(s):

Guillem Lambies ◽

Antonio García de Herreros ◽

Víctor M. Díaz

Keyword(s):

Cell Migration ◽

Translational Control ◽

Epithelial To Mesenchymal Transition ◽

Extracellular Matrix Remodeling ◽

Matrix Remodeling ◽

Mesenchymal Transition ◽

Tgfβ Receptors ◽

Fundamental Process ◽

Multistep Process

Abstract Cell migration is a multifactorial/multistep process that requires the concerted action of growth and transcriptional factors, motor proteins, extracellular matrix remodeling and proteases. In this review, we focus on the role of transcription factors modulating Epithelial-to-Mesenchymal Transition (EMT-TFs), a fundamental process supporting both physiological and pathological cell migration. These EMT-TFs (Snail1/2, Twist1/2 and Zeb1/2) are labile proteins which should be stabilized to initiate EMT and provide full migratory and invasive properties. We present here a family of enzymes, the deubiquitinases (DUBs) which have a crucial role in counteracting polyubiquitination and proteasomal degradation of EMT-TFs after their induction by TGFβ, inflammatory cytokines and hypoxia. We also describe the DUBs promoting the stabilization of Smads, TGFβ receptors and other key proteins involved in transduction pathways controlling EMT.

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