scholarly journals Radially patterned cell behaviours during tube budding from an epithelium

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Yara E Sanchez-Corrales ◽  
Guy B Blanchard ◽  
Katja Röper
Keyword(s):  
Salivary Gland ◽  
Live Imaging ◽  
Drosophila Embryo ◽  
Apical Constriction ◽  
Morphogenetic Process ◽  
Early Stages ◽  
Morphometric Methods ◽  
Pit Cells ◽  
Epithelial Sheets

The budding of tubular organs from flat epithelial sheets is a vital morphogenetic process. Cell behaviours that drive such processes are only starting to be unraveled. Using live-imaging and novel morphometric methods, we show that in addition to apical constriction, radially oriented directional intercalation of cells plays a major contribution to early stages of invagination of the salivary gland tube in the Drosophila embryo. Extending analyses in 3D, we find that near the pit of invagination, isotropic apical constriction leads to strong cell-wedging. Further from the pit cells interleave circumferentially, suggesting apically driven behaviours. Supporting this, junctional myosin is enriched in, and neighbour exchanges are biased towards the circumferential orientation. In a mutant failing pit specification, neither are biased due to an inactive pit. Thus, tube budding involves radially patterned pools of apical myosin, medial as well as junctional, and radially patterned 3D-cell behaviours, with a close mechanical interplay between invagination and intercalation.

scholarly journals Radially-patterned cell behaviours during tube budding from an epithelium

2018 ◽  
Author(s):  
Yara E. Sanchez-Corrales ◽  
Guy B. Blanchard ◽  
Katja Röper
Keyword(s):  
Salivary Gland ◽  
Live Imaging ◽  
Apical Constriction ◽  
Morphogenetic Process ◽  
Early Stages ◽  
Morphometric Methods ◽  
Pit Cells ◽  
Epithelial Sheets

AbstractThe budding of tubular organs from flat epithelial sheets is a vital morphogenetic process. Cell behaviours that drive such processes are only starting to be unraveled. Using live imaging and novel morphometric methods we show that in addition to apical constriction, radially oriented directional intercalation of placodal cells plays a major contribution to the early stages of invagination of the salivary gland tube in the Drosophila embryo. Extending analyses in 3D, we find that near the pit of invagination, isotropic apical constriction leads to strong cell wedging, and further from the pit cells interleave circumferentially, suggesting apically driven behaviours. Supporting this, junctional myosin is enriched in, and neighbour exchanges biased towards the circumferential orientation. In a mutant failing pit specification, neither are biased due to an inactive pit. Thus, tube budding depends on a radially polarised pattern of apical myosin leading to radially oriented 3D cell behaviours, with a close mechanical interplay between invagination and intercalation.

scholarly journals Deconstructing Gastrulation at the Single Cell Level

2021 ◽  
Author(s):  
Tomer Stern ◽  
Sebastian J Streichan ◽  
Stanislav Y Shvartsman ◽  
Eric F Wieschaus
Keyword(s):  
Large Scale ◽  
Drosophila Embryo ◽  
Cell Segmentation ◽  
Model Organisms ◽  
Specific Cell ◽  
Cell Behaviors ◽  
Animal Development ◽  
Wide Range ◽  
Cell Groups ◽  
Epithelial Sheets

Gastrulation movements in all animal embryos start with regulated deformations of patterned epithelial sheets. Current studies of gastrulation use a wide range of model organisms and emphasize either large-scale tissue processes or dynamics of individual cells and cell groups. Here we take a step towards bridging these complementary strategies and deconstruct early stages of gastrulation in the entire Drosophila embryo, where transcriptional patterns in the blastoderm give rise to region-specific cell behaviors. Our approach relies on an integrated computational framework for cell segmentation and tracking and on efficient algorithms for event detection. Our results reveal how thousands of cell shape changes, divisions, and intercalations drive large-scale deformations of the patterned blastoderm, setting the stage for systems-level dissection of a pivotal step in animal development.

scholarly journals Phosphorylation of Pnut in the Early Stages of Drosophila Embryo Development Affects Association of the Septin Complex with the Membrane and Is Important for Viability

2017 ◽  
Vol 8 (1) ◽  
pp. 27-38 ◽  
Author(s):  
Katarina Akhmetova ◽  
Maxim Balasov ◽  
Anton Svitin ◽  
Elena Chesnokova ◽  
Matthew Renfrow ◽  
...  
Keyword(s):  
Embryo Development ◽  
Drosophila Embryo ◽  
Early Stages

Dual Sympathetic Input into Developing Salivary Glands

2019 ◽  
Vol 98 (10) ◽  
pp. 1122-1130 ◽  
Author(s):  
T.H.N. Teshima ◽  
A.S. Tucker ◽  
S.V. Lourenço
Keyword(s):  
Salivary Gland ◽  
Superior Cervical Ganglion ◽  
Time Course ◽  
Sympathetic Nerves ◽  
Branching Morphogenesis ◽  
Developmental Time ◽  
Explant Culture ◽  
Early Stages ◽  
Cervical Ganglion ◽  
Gland Development

Neuronal signaling is known to be required for salivary gland development, with parasympathetic nerves interacting with the surrounding tissues from early stages to maintain a progenitor cell population and control morphogenesis. In contrast, postganglionic sympathetic nerves arrive late in salivary gland development to perform a secretory function; however, no previous report has shown their role during development. Here, we show that a subset of neuronal cells within the parasympathetic submandibular ganglion (PSG) express the catecholaminergic marker tyrosine hydroxylase (TH) in developing murine and human submandibular glands. This sympathetic phenotype coincided with the expression of transcription factor Hand2 within the PSG from the bud stage (E12.5) of mouse embryonic salivary gland development. Hand2 was previously associated with the decision of neural crest cells to become sympathetic in other systems, suggesting a role in controlling neuronal fate in the salivary gland. The PSG therefore provides a population of TH-expressing neurons prior to the arrival of the postganglionic sympathetic axons from the superior cervical ganglion at E15.5. In culture, in the absence of nerves from the superior cervical ganglion, these PSG-derived TH neurons were clearly evident forming a network around the gland. Chemical ablation of dopamine receptors in explant culture with the neurotoxin 6-hydroxydopamine at early stages of gland development resulted in specific loss of the TH-positive neurons from the PSG, and subsequent branching was inhibited. Taken altogether, these results highlight for the first time the detailed developmental time course of TH-expressing neurons during murine salivary gland development and suggest a role for these neurons in branching morphogenesis.

scholarly journals Deficiency screen identifies a novel role for beta 2 tubulin in salivary gland and myoblast migration in the Drosophila embryo

2009 ◽  
Vol 238 (4) ◽  
pp. 853-863 ◽  
Author(s):  
Rakhi Jattani ◽  
Unisha Patel ◽  
Bilal Kerman ◽  
Monn Monn Myat
Keyword(s):  
Salivary Gland ◽  
Drosophila Embryo ◽  
Beta 2

scholarly journals armadillo, bazooka, and stardust are critical for early stages in formation of the zonula adherens and maintenance of the polarized blastoderm epithelium in Drosophila.

1996 ◽  
Vol 134 (1) ◽  
pp. 149-163 ◽  
Author(s):  
H A Müller ◽  
E Wieschaus
Keyword(s):  
Plasma Membranes ◽  
Basolateral Membrane ◽  
Cell Sheet ◽  
Cell Monolayer ◽  
Test System ◽  
Sem Analysis ◽  
Drosophila Embryo ◽  
Early Stages ◽  
A Cell ◽  
The Stability

Cellularization of the Drosophila embryo results in the formation of a cell monolayer with many characteristics of a polarized epithelium. We have used antibodies specific to cellular junctions and nascent plasma membranes to study the formation of the zonula adherens (ZA) in relation to the establishment of basolateral membrane polarity. The same approach was then used as a test system to identify X-linked zygotically active genes required for ZA formation. We show that ZA formation begins during cellularization and that the basolateral membrane domain is established at mid-gastrulation. By creating deficiencies for defined regions of the X chromosome, we have identified genes that are required for the formation of the ZA and the generation of basolateral membrane polarity. We show that embryos mutant for both stardust (sdt) and bazooka (baz) fail to form a ZA. In addition to the failure to establish the ZA, the formation of the monolayered epithelium is disrupted after cellularization, resulting in formation of a multilayered cell sheet by mid-gastrulation. SEM analysis of mutant embryos revealed a conversion of cells exhibiting epithelial characteristics into cells exhibiting mesenchymal characteristics. To investigate how mutations that affect an integral component of the ZA itself influence ZA formation, we examined embryos with reduced maternal and zygotic supply of wild-type Arm protein. These embryos, like embryos mutant for both sdt and baz, exhibit an early disruption of ZA formation. These results suggest that early stages in the assembly of the ZA are critical for the stability of the polarized blastoderm epithelium.

scholarly journals DRhoGEF2 and Diaphanous Regulate Contractile Force during Segmental Groove Morphogenesis in the Drosophila Embryo

2008 ◽  
Vol 19 (5) ◽  
pp. 1883-1892 ◽  
Author(s):  
Shai Mulinari ◽  
Mojgan Padash Barmchi ◽  
Udo Häcker
Keyword(s):  
Cell Shape ◽  
Cell Formation ◽  
Small Gtpases ◽  
Cell Junctions ◽  
Drosophila Embryo ◽  
Cell Cortex ◽  
Nucleotide Exchange ◽  
Apical Constriction ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factors

Morphogenesis of the Drosophila embryo is associated with dynamic rearrangement of the actin cytoskeleton mediated by small GTPases of the Rho family. These GTPases act as molecular switches that are activated by guanine nucleotide exchange factors. One of these factors, DRhoGEF2, plays an important role in the constriction of actin filaments during pole cell formation, blastoderm cellularization, and invagination of the germ layers. Here, we show that DRhoGEF2 is equally important during morphogenesis of segmental grooves, which become apparent as tissue infoldings during mid-embryogenesis. Examination of DRhoGEF2-mutant embryos indicates a role for DRhoGEF2 in the control of cell shape changes during segmental groove morphogenesis. Overexpression of DRhoGEF2 in the ectoderm recruits myosin II to the cell cortex and induces cell contraction. At groove regression, DRhoGEF2 is enriched in cells posterior to the groove that undergo apical constriction, indicating that groove regression is an active process. We further show that the Formin Diaphanous is required for groove formation and strengthens cell junctions in the epidermis. Morphological analysis suggests that Dia regulates cell shape in a way distinct from DRhoGEF2. We propose that DRhoGEF2 acts through Rho1 to regulate acto-myosin constriction but not Diaphanous-mediated F-actin nucleation during segmental groove morphogenesis.

scholarly journals Cell polarity determinant Dlg1 facilitates epithelial invagination by promoting tissue-scale mechanical coordination

2021 ◽  
Author(s):  
Melisa Andrea Fuentes ◽  
Bing He
Keyword(s):  
Laser Ablation ◽  
Cell Polarity ◽  
Cortical Actin ◽  
Multilayered Structures ◽  
Directed Movement ◽  
Apical Constriction ◽  
Mechanical Coupling ◽  
Apical Domain ◽  
Epithelial Sheets ◽  
Fundamental Mechanism

Epithelial folding mediated by apical constriction serves as a fundamental mechanism to convert flat epithelial sheets into multilayered structures. It remains elusive whether additional mechanical inputs are required for folding mediated by apical constriction. Using Drosophila mesoderm invagination as a model, we identified an important role for the non-constricting, lateral mesodermal cells adjacent to the constriction domain ("flanking cells") in facilitating epithelial folding. We found that depletion of the basolateral determinant, Dlg1, disrupts the transition between apical constriction and invagination without affecting the rate of apical constriction. Strikingly, the observed delay in invagination is associated with ineffective apical myosin contractions in the flanking cells that lead to overstretching of their apical domain. The defects in the flanking cells impede ventral-directed movement of the lateral ectoderm, suggesting reduced mechanical coupling between tissues. Specifically disrupting the flanking cells in wildtype embryos by laser ablation or optogenetic depletion of cortical actin is sufficient to delay the apical constriction-to-invagination transition. Our findings indicate that effective mesoderm invagination requires intact flanking cells and suggest a role for tissue-scale mechanical coupling during epithelial folding.

scholarly journals Regulation of apical constriction via microtubule- and Rab11-dependent apical transport during tissue invagination

2021 ◽  
Vol 32 (10) ◽  
pp. 1033-1047
Author(s):  
Thao Phuong Le ◽  
SeYeon Chung
Keyword(s):  
Salivary Gland ◽  
Tube Formation ◽  
Apical Constriction ◽  
Epithelial Tube ◽  
Cellular Forces

During tissue invagination, contractile actomyosin structures generate the cellular forces that drive apical constriction. Using the Drosophila embryonic salivary gland as a model for epithelial tube formation, we show that microtubule- and Rab11-dependent apical transport is critical for regulating actomyosin networks during invagination.

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