Biology subjects

Inaki, M.

Publications and source records attributed to Inaki, M..

3 recordsLinked to original sources

bioRxiv2021

Live imaging of delamination in Drosophila shows that epithelial cell motility and invasiveness are independently regulated

Delaminating cells undergo complex, precisely regulated changes in cell-cell adhesion, motility, polarity, invasiveness, and other cellular properties. Delamination occurs during development and in pathogenic conditions such as cancer metastasis. We analyzed the requirements for epithelial delamination in Drosophila ovary border cells, which detach from the structured epithelial layer and begin to migrate collectively. We used live imaging to examine cellular dynamics, particularly epithelial cells acquisition of motility and invasiveness, in delamination-defective mutants during the time period in which delamination occurs in the wild-type ovary. We found that border cells in slow border cells (slbo), a delamination-defective mutant, lacked invasive cellular protrusions but acquired motility, while JAK/STAT-inhibited border cells lost both invasiveness and motility. Our results indicate that invasiveness and motility, which are cooperatively required for delamination, are regulated independently. Our reconstruction experiments also showed that motility is not a prerequisite for acquiring invasiveness. Summary statementLive imaging of epithelial delamination reveals that cell motility and invasiveness, both of which are required for delamination, are regulated independently and that motility is not a prerequisite for invasiveness.

developmental biology↗

bioRxiv2020

Collective nuclear behavior shapes bilateral nuclear symmetry for subsequent left-right asymmetric morphogenesis in Drosophila

Proper organ development often requires nuclei to move to a specific position within the cell. To determine how nuclear positioning affects left-right (LR) development in the Drosophila anterior midgut (AMG), we developed a surface-modeling method to measure and describe nuclear behavior at stages 13-14, captured in three-dimensional time-lapse movies. We describe the distinctive positioning and a novel collective nuclear behavior by which nuclei align LR-symmetrically along the anterior-posterior axis in the visceral muscles that overlie the midgut and are responsible for this organs LR-asymmetric development. Wnt4 signaling is crucial for the collective behavior and proper positioning of the nuclei, as are myosin II and LINC complex, without which the nuclei failed to align LR-symmetrically. The LR-symmetric positioning of the nuclei is important for the subsequent LR-asymmetric development of the AMG. We propose that the bilaterally symmetrical positioning of these nuclei may be mechanically coupled with subsequent LR-asymmetric morphogenesis.

cell biology↗

bioRxiv2020

Statistical validation verifies that enantiomorphic states of cell chirality are determinant dictating the left- or right-handed direction of the hindgut rotation in Drosophila

In the left-right (LR) asymmetric development of invertebrates, chirality of cells (cell chirality) plays crucial roles. Left- or right-handed structure of cells consequently directs the morphogenesis with corresponding LR asymmetry. In Drosophila, it has been suggested that cell chirality drives the LR-asymmetric development of various organs including the embryonic hindgut. However, this hypothesis is supported only by apparent concordance between these two events and by computer simulations connecting them [1-5]. Therefore, here, we mathematically evaluated the causal relationship between the cell chirality of the hindgut epithelial cells and the LR-directional rotation of the hindgut, which was previously postulated. Our logistic model obtained from various genetic backgrounds significantly explained the correlation between the enantiomorphic states of cell chirality and the LR directionality of hindgut rotation. This model also significantly explained the correlation between cell chirality stochastically formed in advance in each living embryo and the LR-directionality of the following rotation, suggesting the irrelevance of modes how cell chirality is formed. This analysis also showed that the cell chirality is not only sufficient but also required for the rotation. Considering the chronological order of these events, our study validated that cell chirality causally defines the LR asymmetry of the hindgut rotation.

developmental biology↗