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1.
Development ; 148(4)2021 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-33526583

RESUMO

Basement membranes (BM) are extracellular matrices assembled into complex and highly organized networks essential for organ morphogenesis and function. However, little is known about the tissue origin of BM components and their dynamics in vivo Here, we unravel the assembly and role of the BM main component, Collagen type IV (ColIV), in Drosophila ovarian stalk morphogenesis. Stalks are short strings of cells assembled through cell intercalation that link adjacent follicles and maintain ovarian integrity. We show that stalk ColIV has multiple origins and is assembled following a regulated pattern leading to a unique BM organisation. Absence of ColIV leads to follicle fusion, as observed upon ablation of stalk cells. ColIV and integrins are both required to trigger cell intercalation and maintain mechanically strong cell-cell attachment within the stalk. These results show how the dynamic assembly of a mosaic BM controls complex tissue morphogenesis and integrity.


Assuntos
Membrana Basal/metabolismo , Comunicação Celular , Drosophila/embriologia , Drosophila/metabolismo , Ovário/embriologia , Ovário/metabolismo , Animais , Colágeno Tipo IV/metabolismo , Matriz Extracelular/metabolismo , Feminino , Imunofluorescência , Morfogênese , Organogênese , Hipófise/embriologia , Hipófise/metabolismo
2.
PLoS Genet ; 16(4): e1008758, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32324733

RESUMO

Left-Right (LR) asymmetry is essential for organ positioning, shape and function. Myosin 1D (Myo1D) has emerged as an evolutionary conserved chirality determinant in both Drosophila and vertebrates. However, the molecular interplay between Myo1D and the actin cytoskeleton underlying symmetry breaking remains poorly understood. To address this question, we performed a dual genetic screen to identify new cytoskeletal factors involved in LR asymmetry. We identified the conserved actin nucleator DAAM as an essential factor required for both dextral and sinistral development. In the absence of DAAM, organs lose their LR asymmetry, while its overexpression enhances Myo1D-induced de novo LR asymmetry. These results show that DAAM is a limiting, LR-specific actin nucleator connecting up Myo1D with a dedicated F-actin network important for symmetry breaking.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Padronização Corporal , Proteínas de Drosophila/metabolismo , Citoesqueleto de Actina/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Drosophila , Proteínas de Drosophila/genética , Miosinas/genética , Miosinas/metabolismo
3.
Development ; 145(14)2018 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-29980565

RESUMO

Understanding how different cell types acquire their motile behaviour is central to many normal and pathological processes. Drosophila border cells represent a powerful model for addressing this issue and to specifically decipher the mechanisms controlling collective cell migration. Here, we identify the Drosophila Insulin/Insulin-like growth factor signalling (IIS) pathway as a key regulator in controlling actin dynamics in border cells, independently of its function in growth control. Loss of IIS activity blocks the formation of actin-rich long cellular extensions that are important for the delamination and the migration of the invasive cluster. We show that IIS specifically activates the expression of the actin regulator chickadee, the Drosophila homolog of Profilin, which is essential for promoting the formation of actin extensions and migration through the egg chamber. In this process, the transcription factor FoxO acts as a repressor of chickadee expression. Altogether, these results show that local activation of IIS controls collective cell migration through regulation of actin homeostasis and protrusion dynamics.


Assuntos
Actinas/metabolismo , Movimento Celular , Extensões da Superfície Celular/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/metabolismo , Insulinas/metabolismo , Animais , Proteínas de Drosophila , Feminino , Folículo Ovariano/citologia , Folículo Ovariano/metabolismo , Profilinas , Receptor de Insulina/metabolismo , Transdução de Sinais , Imagem com Lapso de Tempo
4.
Nat Commun ; 9(1): 1942, 2018 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-29769531

RESUMO

The establishment of left-right (LR) asymmetry is fundamental to animal development, but the identification of a unifying mechanism establishing laterality across different phyla has remained elusive. A cilia-driven, directional fluid flow is important for symmetry breaking in numerous vertebrates, including zebrafish. Alternatively, LR asymmetry can be established independently of cilia, notably through the intrinsic chirality of the acto-myosin cytoskeleton. Here, we show that Myosin1D (Myo1D), a previously identified regulator of Drosophila LR asymmetry, is essential for the formation and function of the zebrafish LR organizer (LRO), Kupffer's vesicle (KV). Myo1D controls the orientation of LRO cilia and interacts functionally with the planar cell polarity (PCP) pathway component VanGogh-like2 (Vangl2), to shape a productive LRO flow. Our findings identify Myo1D as an evolutionarily conserved regulator of animal LR asymmetry, and show that functional interactions between Myo1D and PCP are central to the establishment of animal LR asymmetry.


Assuntos
Padronização Corporal/genética , Miosinas/genética , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/genética , Animais , Animais Geneticamente Modificados , Polaridade Celular/genética , Cílios/genética , Cílios/metabolismo , Embrião não Mamífero/embriologia , Embrião não Mamífero/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Fatores de Determinação Direita-Esquerda/genética , Fatores de Determinação Direita-Esquerda/metabolismo , Mutação , Miosinas/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/metabolismo
5.
PLoS Genet ; 13(2): e1006640, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28231245

RESUMO

Tissue morphogenesis relies on proper differentiation of morphogenetic domains, adopting specific cell behaviours. Yet, how signalling pathways interact to determine and coordinate these domains remains poorly understood. Dorsal closure (DC) of the Drosophila embryo represents a powerful model to study epithelial cell sheet sealing. In this process, JNK (JUN N-terminal Kinase) signalling controls leading edge (LE) differentiation generating local forces and cell shape changes essential for DC. The LE represents a key morphogenetic domain in which, in addition to JNK, a number of signalling pathways converges and interacts (anterior/posterior -AP- determination; segmentation genes, such as Wnt/Wingless; TGFß/Decapentaplegic). To better characterize properties of the LE morphogenetic domain, we sought out new JNK target genes through a genomic approach: 25 were identified of which 8 are specifically expressed in the LE, similarly to decapentaplegic or puckered. Quantitative in situ gene profiling of this new set of LE genes reveals complex patterning of the LE along the AP axis, involving a three-way interplay between the JNK pathway, segmentation and HOX genes. Patterning of the LE into discrete domains appears essential for coordination of tissue sealing dynamics. Loss of anterior or posterior HOX gene function leads to strongly delayed and asymmetric DC, due to incorrect zipping in their respective functional domain. Therefore, in addition to significantly increasing the number of JNK target genes identified so far, our results reveal that the LE is a highly heterogeneous morphogenetic organizer, sculpted through crosstalk between JNK, segmental and AP signalling. This fine-tuning regulatory mechanism is essential to coordinate morphogenesis and dynamics of tissue sealing.


Assuntos
Diferenciação Celular/genética , Desenvolvimento Embrionário/genética , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Morfogênese/genética , Animais , Padronização Corporal/genética , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Ectoderma/crescimento & desenvolvimento , Ectoderma/metabolismo , Embrião não Mamífero , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteínas Quinases JNK Ativadas por Mitógeno/biossíntese , Sistema de Sinalização das MAP Quinases/genética , Fenótipo
6.
Cell Rep ; 13(3): 546-560, 2015 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-26456819

RESUMO

The extracellular matrix plays an essential role for stem cell differentiation and niche homeostasis. Yet, the origin and mechanism of assembly of the stem cell niche microenvironment remain poorly characterized. Here, we uncover an association between the niche and blood cells, leading to the formation of the Drosophila ovarian germline stem cell niche basement membrane. We identify a distinct pool of plasmatocytes tightly associated with the developing ovaries from larval stages onward. Expressing tagged collagen IV tissue specifically, we show that the germline stem cell niche basement membrane is produced by these "companion plasmatocytes" in the larval gonad and persists throughout adulthood, including the reproductive period. Eliminating companion plasmatocytes or specifically blocking their collagen IV expression during larval stages results in abnormal adult niches with excess stem cells, a phenotype due to aberrant BMP signaling. Thus, local interactions between the niche and blood cells during gonad development are essential for adult germline stem cell niche microenvironment assembly and homeostasis.


Assuntos
Hemócitos/citologia , Homeostase , Oogônios/citologia , Nicho de Células-Tronco , Animais , Colágeno Tipo IV/metabolismo , Drosophila/citologia , Drosophila/crescimento & desenvolvimento , Drosophila/metabolismo , Matriz Extracelular/metabolismo , Hemócitos/metabolismo , Oogênese , Oogônios/metabolismo
7.
Dev Cell ; 33(6): 675-89, 2015 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-26073018

RESUMO

Left-right (LR) asymmetry is essential for organ development and function in metazoans, but how initial LR cue is relayed to tissues still remains unclear. Here, we propose a mechanism by which the Drosophila LR determinant Myosin ID (MyoID) transfers LR information to neighboring cells through the planar cell polarity (PCP) atypical cadherin Dachsous (Ds). Molecular interaction between MyoID and Ds in a specific LR organizer controls dextral cell polarity of adjoining hindgut progenitors and is required for organ looping in adults. Loss of Ds blocks hindgut tissue polarization and looping, indicating that Ds is a crucial factor for both LR cue transmission and asymmetric morphogenesis. We further show that the Ds/Fat and Frizzled PCP pathways are required for the spreading of LR asymmetry throughout the hindgut progenitor tissue. These results identify a direct functional coupling between the LR determinant MyoID and PCP, essential for non-autonomous propagation of early LR asymmetry.


Assuntos
Padronização Corporal/fisiologia , Caderinas/fisiologia , Sistema Digestório/crescimento & desenvolvimento , Proteínas de Drosophila/fisiologia , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/fisiologia , Animais , Animais Geneticamente Modificados , Padronização Corporal/genética , Caderinas/genética , Polaridade Celular/genética , Polaridade Celular/fisiologia , Sistema Digestório/citologia , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Genes de Insetos , Modelos Biológicos , Miosinas/genética , Miosinas/fisiologia
8.
PLoS One ; 8(12): e82908, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24349395

RESUMO

Molecular motors transport various cargoes including vesicles, proteins and mRNAs, to distinct intracellular compartments. A significant challenge in the field of nanotechnology is to improve drug nuclear delivery by engineering nanocarriers transported by cytoskeletal motors. However, suitable in vivo models to assay transport and delivery efficiency remain very limited. Here, we develop a fast and genetically tractable assay to test the efficiency and dynamics of fluospheres (FS) using microinjection into Drosophila oocytes coupled with time-lapse microscopy. We designed dynein motor driven FS using a collection of dynein light chain 8 (LC8) peptide binding motifs as molecular linkers and characterized in real time the efficiency of the FS movement according to its linker's sequence. Results show that the conserved LC8 binding motif allows fast perinuclear nanoparticle's accumulation in a microtubule and dynein dependent mechanism. These data reveal the Drosophila oocyte as a new valuable tool for the design of motor driven nanovectors.


Assuntos
Citoesqueleto/metabolismo , Proteínas de Drosophila/química , Sistemas de Liberação de Medicamentos , Dineínas/química , Nanopartículas/química , Oócitos/metabolismo , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Proteínas de Drosophila/metabolismo , Drosophila melanogaster , Dineínas/metabolismo , Oócitos/citologia
9.
Development ; 139(10): 1874-84, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22491943

RESUMO

In bilateria, positioning and looping of visceral organs requires proper left-right (L/R) asymmetry establishment. Recent work in Drosophila has identified a novel situs inversus gene encoding the unconventional type ID myosin (MyoID). In myoID mutant flies, the L/R axis is inverted, causing reversed looping of organs, such as the gut, spermiduct and genitalia. We have previously shown that MyoID interacts physically with ß-Catenin, suggesting a role of the adherens junction in Drosophila L/R asymmetry. Here, we show that DE-Cadherin co-immunoprecipitates with MyoID and is required for MyoID L/R activity. We further demonstrate that MyoIC, a closely related unconventional type I myosin, can antagonize MyoID L/R activity by preventing its binding to adherens junction components, both in vitro and in vivo. Interestingly, DE-Cadherin inhibits MyoIC, providing a protective mechanism to MyoID function. Conditional genetic experiments indicate that DE-Cadherin, MyoIC and MyoID show temporal synchronicity for their function in L/R asymmetry. These data suggest that following MyoID recruitment by ß-Catenin at the adherens junction, DE-Cadherin has a twofold effect on Drosophila L/R asymmetry by promoting MyoID activity and repressing that of MyoIC. Interestingly, the product of the vertebrate situs inversus gene inversin also physically interacts with ß-Catenin, suggesting that the adherens junction might serve as a conserved platform for determinants to establish L/R asymmetry both in vertebrates and invertebrates.


Assuntos
Padronização Corporal/fisiologia , Caderinas/metabolismo , Proteínas de Drosophila/metabolismo , Miosinas/metabolismo , Animais , Padronização Corporal/genética , Caderinas/genética , Drosophila , Proteínas de Drosophila/genética , Imunoprecipitação , Miosina Tipo I/genética , Miosina Tipo I/metabolismo , Miosinas/genética , Ligação Proteica , beta Catenina/genética , beta Catenina/metabolismo
10.
Development ; 138(7): 1383-93, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21350010

RESUMO

The transition from immotile epithelial cells to migrating cells occurs in all organisms during normal embryonic development, as well as during tumour metastasis. During Drosophila oogenesis, border cells (BCs) are recruited and delaminate from the follicular epithelium. This process is triggered by the polar cells (PCs), which secrete the cytokine Unpaired (Upd) and activate the JAK/STAT pathway in neighbouring cells, turning them into invasive BCs. Interestingly, either a decrease or an increase in BC number alters migration, indicating that mechanisms controlling the level of JAK/STAT signalling are crucial in this process. Here, we show that PCs have a highly stable and polarised network of microtubules along which upd transcripts are asymmetrically transported in a Dynein-dependent manner. We demonstrate that in the absence of upd mRNA localisation the ligand is no longer efficiently secreted, leading to a loss of signalling strength as well as recruitment and migration defects. These findings reveal a novel post-transcriptional regulatory mechanism of JAK/STAT signalling in the control of epithelial cell invasiveness.


Assuntos
Movimento Celular/fisiologia , Citocinas/metabolismo , Janus Quinases/metabolismo , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais/fisiologia , Animais , Citocinas/genética , Drosophila , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Feminino , Imuno-Histoquímica , Hibridização In Situ , Janus Quinases/genética , Microtúbulos/genética , Microtúbulos/metabolismo , Oogênese/fisiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Transcrição STAT/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
11.
EMBO Rep ; 9(7): 676-82, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18552769

RESUMO

Small GTPases of the Ras-like (Ral) family are crucial for signalling functions in both normal and cancer cells; however, their role in a developing organism is poorly understood. Here, we identify the Drosophila Ral homologue RalA as a new key regulator of polar-cell differentiation during oogenesis. Polar cells have a crucial role in patterning the egg chamber and in recruiting border cells, which undergo collective and guided migration. We show that RalA function is essential for the maintenance of anterior and posterior polar-cell fate and survival. RalA is required cell autonomously to control the expression of polar-cell-specific markers, including the Jak/Stat ligand Unpaired. The loss of RalA also causes a cell non-autonomous phenotype owing to reduced Jak/Stat signalling in neighbouring follicle cells. As a result, border-cell assembly and migration as well as the polarization of the oocyte are defective. Thus, RalA is required in organizing centres to control proper patterning and migration in vivo.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/enzimologia , Janus Quinases/metabolismo , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Folículo Ovariano/enzimologia , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais , Animais , Diferenciação Celular , Movimento Celular , Polaridade Celular , Drosophila melanogaster/citologia , Feminino , Mutação/genética , Folículo Ovariano/citologia , Transporte Proteico , Frações Subcelulares/metabolismo
12.
Development ; 129(23): 5437-47, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12403714

RESUMO

In mammals, the JAK/STAT (Janus Kinase/Signal Transducer and Activator of Transcription) signaling pathway is activated in response to cytokines and growth factors to control blood cell development, proliferation and cell determination. In Drosophila, a conserved JAK/STAT signaling pathway controls segmentation in embryos, as well as blood cell development and other processes in larvae and adults. During embryogenesis, transduction of the Unpaired [Upd; also known as Outstretched (Os)] ligand through the JAK/STAT pathway requires Domeless, a putative membrane protein with distant homology to vertebrate type I cytokine receptors. We have isolated domeless (dome) in a screen to identify genes essential in epithelial morphogenesis during oogenesis. The level of dome activity is critical for proper border cell migration and is controlled in part through a negative feedback loop. In addition to its essential role in border cells, we show that dome is required in the germarium for the polarization of follicle cells during encapsulation of germline cells. In this process, dome controls the expression of the apical determinant Crumbs. In contrast to the ligand Upd, whose expression is limited to a pair of polar cells at both ends of the egg chamber, dome is expressed in all germline and follicle cells. However, the Dome protein is specifically localized at apicolateral membranes and undergoes ligand-dependent internalization in the follicle cells. dome mutations interact genetically with JAK/STAT pathway genes in border cell migration and abolish the nuclear translocation of Stat92E in vivo. We also show that dome functions downstream of upd and that both the extracellular and intracellular domains of Dome are required for JAK/STAT signaling. Altogether, our data indicate that Dome is an essential receptor molecule for Upd and JAK/STAT signaling during oogenesis.


Assuntos
Movimento Celular/fisiologia , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/embriologia , Células Epiteliais/metabolismo , Proteínas de Membrana , Oogênese/fisiologia , Receptores de Interleucina/metabolismo , Transdução de Sinais/fisiologia , Fatores de Transcrição , Animais , Animais Geneticamente Modificados , Polaridade Celular , Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/fisiologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Genes de Insetos , Genes Reporter , Glicoproteínas/metabolismo , Proteínas de Insetos/metabolismo , Janus Quinase 1 , Morfogênese , Folículo Ovariano/citologia , Folículo Ovariano/metabolismo , Proteínas Tirosina Quinases/metabolismo , Receptores de Interleucina/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Fator de Transcrição STAT1 , Transativadores/metabolismo
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