scholarly journals Cytoplasmic flows caused by actomyosin contraction drive interkinetic nuclear migration

2020 ◽  
Author(s):  
Amarendra Badugu ◽  
Andres Käch
Keyword(s):  
Nuclear Migration ◽  
Hydraulic Cylinder ◽  
Apical Position ◽  
Drosophila Wing ◽  
Interkinetic Nuclear Migration ◽  
Medial Surfaces ◽  
Wing Discs ◽  
Contractile Forces ◽  
Short Time ◽  
Actomyosin Contraction

AbstractInterkinetic nuclear migration (IKNM) is the process by which the nucleus migrates between apical and medial surfaces of pseudostratified epithelia. Previous studies have proposed force generating mechanisms, acting primarily on the nucleus. Having observed in drosophila wing discs that cytoplasmic components (lipid droplets and mitochondria) migrate alongside the nucleus, we used live imaging and particle tracking to demonstrate that the cytoplasm flows are responsible for the nucleus migration. We identify that nuclear migration in mitotic cells is preceded by a fast basal-to-apical flow of cytoplasm occurring over short time scales. We further show that, for the migration of basally located nuclei to an apical position, a slower flow of cytoplasm is responsible over a longer time scale. Our findings indicate that these flows are driven by acto-myosin contractile forces. These flows increase the hydrostatic pressure under the nucleus to exert a lifting force, much like a piston in a hydraulic cylinder.

Quantitative EM of gap junction distribution in mutant drosophila wing discs

1983 ◽  
Vol 41 ◽  
pp. 720-721
Author(s):  
J.S. Ryerse
Keyword(s):  
Gap Junctions ◽  
Growth Control ◽  
Intercellular Junctions ◽  
Wing Disc ◽  
En Bloc ◽  
Metabolic Cooperation ◽  
Drosophila Wing ◽  
Adult Wing ◽  
Wing Discs ◽  
Wing Pouch

Gap junctions are intercellular junctions found in both vertebrates and invertebrates through which ions and small molecules can pass. Their distribution in tissues could be of critical importance for ionic coupling or metabolic cooperation between cells or for regulating the intracellular movement of growth control and pattern formation factors. Studies of the distribution of gap junctions in mutants which develop abnormally may shed light upon their role in normal development. I report here the distribution of gap junctions in the wing pouch of 3 Drosophila wing disc mutants, vg (vestigial) a cell death mutant, 1(2)gd (lethal giant disc) a pattern abnormality mutant and 1(2)gl (lethal giant larva) a neoplastic mutant and compare these with wildtype wing discs.The wing pouch (the anlagen of the adult wing blade) of a wild-type wing disc is shown in Fig. 1 and consists of columnar cells (Fig. 5) joined by gap junctions (Fig. 6). 14000x EMs of conventionally processed, UA en bloc stained, longitudinally sectioned wing pouches were enlarged to 45000x with a projector and tracings were made on which the lateral plasma membrane (LPM) and gap junctions were marked.

Interkinetic nuclear migration in the tracheal and esophageal epithelia of the mouse embryo: Possible implications for tracheo-esophageal anomalies

2017 ◽  
Vol 58 (2) ◽  
pp. 62-70 ◽  
Author(s):  
Ryo Kaneda ◽  
Yuko Saeki ◽  
Dereje Getachew ◽  
Akihiro Matsumoto ◽  
Motohide Furuya ◽  
...  
Keyword(s):  
Mouse Embryo ◽  
Nuclear Migration ◽  
Interkinetic Nuclear Migration

scholarly journals Cephalopod Retinal Development Shows Vertebrate-like Mechanisms of Neurogenesis

2021 ◽  
Author(s):  
Francesca Napoli ◽  
Christina M Daly ◽  
Stephanie Neal ◽  
Kyle J McCulloch ◽  
Alexandra Zaloga ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Nervous System ◽  
Progenitor Cells ◽  
Cellular Proliferation ◽  
Imaging Techniques ◽  
Nuclear Migration ◽  
Live Imaging ◽  
Cellular Mechanisms ◽  
High Resolution Data ◽  
Interkinetic Nuclear Migration

Neurogenesis, the regulation of cellular proliferation and differentiation in the developing nervous system, is the process that underlies the diversity of size and cell type found in animal nervous systems. Our understanding of how this process has evolved is limited because of the lack of high resolution data and live-imaging methods across species. The retina is a classic model for the study of neurogenesis in vertebrates and live-imaging of the retina has shown that during development, progenitor cells are organized in a pseudostratified neuroepithelium and nuclei migrate in coordination with the cell cycle along the apicobasal axis of the cell, a process called interkinetic nuclear migration. Eventually cells delaminate and differentiate within the boundaries of the epithelium. This process has been considered unique to vertebrates and thought to be important in maintaining organization during the development of a complex nervous system. Coleoid cephalopods, including squid, cuttlefish and octopus, have the largest nervous system of any invertebrate and convergently-evolved camera-type eyes, making them a compelling comparative system to vertebrates. Here we have pioneered live-imaging techniques to show that the squid, Doryteuthis pealeii, displays cellular mechanisms during cephalopod retinal neurogenesis that are hallmarks of vertebrate processes. We find that retinal progenitor cells in the squid undergo interkinetic nuclear migration until they exit the cell cycle, we identify retinal organization corresponding to progenitor, post-mitotic and differentiated cells, and we find that Notch signaling regulates this process. With cephalopods and vertebrates having diverged 550 million years ago, these results suggest that mechanisms thought to be unique to vertebrates may be common to highly proliferative neurogenic primordia contributing to a large nervous system.

scholarly journals Endocytosis of Wingless via a dynamin-independent pathway is necessary for signaling in Drosophila wing discs

2016 ◽  
Vol 113 (45) ◽  
pp. E6993-E7002 ◽  
Author(s):  
Anupama Hemalatha ◽  
Chaitra Prabhakara ◽  
Satyajit Mayor
Keyword(s):  
Signal Transduction ◽  
Wing Disc ◽  
Low Ph ◽  
Endocytic Pathway ◽  
Apical Surface ◽  
Receptor Complexes ◽  
Drosophila Wing ◽  
Wing Discs ◽  
Ph Dependent ◽  
Endocytic Pathways

Endocytosis of ligand-receptor complexes regulates signal transduction during development. In particular, clathrin and dynamin-dependent endocytosis has been well studied in the context of patterning of the Drosophila wing disc, wherein apically secreted Wingless (Wg) encounters its receptor, DFrizzled2 (DFz2), resulting in a distinctive dorso-ventral pattern of signaling outputs. Here, we directly track the endocytosis of Wg and DFz2 in the wing disc and demonstrate that Wg is endocytosed from the apical surface devoid of DFz2 via a dynamin-independent CLIC/GEEC pathway, regulated by Arf1, Garz, and class I PI3K. Subsequently, Wg containing CLIC/GEEC endosomes fuse with DFz2-containing vesicles derived from the clathrin and dynamin-dependent endocytic pathway, which results in a low pH-dependent transfer of Wg to DFz2 within the merged and acidified endosome to initiate Wg signaling. The employment of two distinct endocytic pathways exemplifies a mechanism wherein cells in tissues leverage multiple endocytic pathways to spatially regulate signaling.

scholarly journals Gap Junctions/Hemichannels Modulate Interkinetic Nuclear Migration in the Forebrain Precursors

2010 ◽  
Vol 30 (12) ◽  
pp. 4197-4209 ◽  
Author(s):  
X. Liu ◽  
K. Hashimoto-Torii ◽  
M. Torii ◽  
C. Ding ◽  
P. Rakic
Keyword(s):  
Gap Junctions ◽  
Nuclear Migration ◽  
Interkinetic Nuclear Migration
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