scholarly journals Denise Montell: Lighting the way in border cell migration

2011 ◽  
Vol 195 (4) ◽  
pp. 540-541
Author(s):  
Caitlin Sedwick
Keyword(s):  
Cell Migration ◽  
Border Cells ◽  
Collective Migration ◽  
Drosophila Oogenesis ◽  
Border Cell ◽  
Border Cell Migration ◽  
The Way

Montell studies Drosophila oogenesis, focusing primarily on the collective migration of border cells.

scholarly journals Temporal coordination of collective migration and lumen formation by antagonism between two nuclear receptors

2020 ◽  
Author(s):  
Xianping Wang ◽  
Heng Wang ◽  
Lin Liu ◽  
Sheng Li ◽  
Gregory Emery ◽  
...  
Keyword(s):  
Cell Migration ◽  
Nuclear Receptors ◽  
Temporal Order ◽  
Time Interval ◽  
Border Cells ◽  
Collective Migration ◽  
Lumen Formation ◽  
Border Cell ◽  
Egg Chambers ◽  
Border Cell Migration

SummaryDuring development, cells often undergo multiple, distinct morphogenetic processes to form a tissue or organ, but how their temporal order and time interval are determined remain poorly understood. Here we show that the nuclear receptors E75 and DHR3 regulate the temporal order and time interval between the collective migration and lumen formation of a coherent group of about 8 cells called border cells during Drosophila oogenesis. In wild type egg chambers, border cells need to first collectively migrate to the anterior border of oocyte before undergoing lumen formation to form micropyle, the structure that is essential for sperm entry into the oocyte. We show that E75 is required for border cell migration and it antagonizes the activity of DHR3, which is necessary and sufficient for the subsequent lumen formation during micropyle formation. Furthermore, E75’s loss of function or DHR3 overexpression each leads to precocious lumen formation before collective migration, an incorrect temporal order for the two morphogenetic processes. Interestingly, both E75 and DHR3’s levels are simultaneously elevated in response to signaling from the EcR, a steroid hormone receptor that initiates border cell migration. Subsequently, the decrease of E75 levels in response to decreased EcR signaling leads to the de-repression of DHR3’s activity and hence switch-on of lumen formation, contributing to the regulation of time interval between collective migration and micropyle formation.

scholarly journals Nuclear lamins promote protrusion dynamics and collective, confined migration in vivo

2021 ◽  
Author(s):  
Lauren Penfield ◽  
Denise Montell
Keyword(s):  
Cell Migration ◽  
Nurse Cells ◽  
Border Cells ◽  
Collective Migration ◽  
Cell Nuclei ◽  
Migration Path ◽  
Border Cell ◽  
Nuclear Lamins ◽  
Border Cell Migration

Cells migrate collectively through confined environments during development and cancer metastasis. While the nucleus, a large and stiff organelle, impedes cell migration between non-deformable pillars in vitro, its function in vivo may vary depending on the microenvironment. Further, it is unknown how nuclei contribute to collective migration in vivo and whether nuclei in different positions within cell collectives experience different forces. Here, we use border cell migration in the fly ovary as an in vivo model to investigate the effects of confined, collective migration on nuclei and the contribution of nuclear lamins to migration. We found severe yet transient nuclear deformations occur, particularly in the leading cell, as border cells squeeze through tiny crevices between germline cells, termed nurse cells. Leading cells extend protrusions between nurse cells, which may pry open space to allow the cluster to advance. Here we report that the leading cell nuclei deformed as they moved into leading protrusions. Then as protrusions widened, the nucleus recovered a more circular shape. These data suggest that lead cell nuclei may help protrusions expand and thereby enlarge the migration path. To test how nuclei might promote or impede border cell migration, we investigated nuclear lamins, proteins that assemble into intermediate filaments and structurally support the nuclear envelope. Depletion of the Drosophila B-type lamin, Lam, from the outer, motile border cells, but not the inner, nonmotile polar cells, impeded border cell migration, whereas perturbations of the A-type lamin, LamC, did not. While wild type border cell clusters typically have one large leading protrusion as they delaminate from the anterior follicular epithelium, clusters depleted of B-type lamin had multiple, short-lived protrusions, resulting in unproductive cluster movement and failure to progress along the migration path. Further, border cell nuclei depleted of B-type lamins were small, formed blebs, and ruptured. Together, these data indicate that B-type lamin is requied for nuclear integrity, which in turn stabilizes the leading protrusion and promotes overall cluster polarization and collective movement through confined spaces.

scholarly journals The Hippo pathway polarizes the actin cytoskeleton during collective migration of Drosophila border cells

2013 ◽  
Vol 201 (6) ◽  
pp. 875-885 ◽  
Author(s):  
Eliana P. Lucas ◽  
Ichha Khanal ◽  
Pedro Gaspar ◽  
Georgina C. Fletcher ◽  
Cedric Polesello ◽  
...  
Keyword(s):  
Cell Migration ◽  
Actin Cytoskeleton ◽  
Actin Polymerization ◽  
Hippo Pathway ◽  
Hippo Signaling ◽  
Border Cells ◽  
Collective Migration ◽  
Protein Activity ◽  
Border Cell ◽  
Border Cell Migration

Collective migration of Drosophila border cells depends on a dynamic actin cytoskeleton that is highly polarized such that it concentrates around the outer rim of the migrating cluster of cells. How the actin cytoskeleton becomes polarized in these cells to enable collective movement remains unknown. Here we show that the Hippo signaling pathway links determinants of cell polarity to polarization of the actin cytoskeleton in border cells. Upstream Hippo pathway components localize to contacts between border cells inside the cluster and signal through the Hippo and Warts kinases to polarize actin and promote border cell migration. Phosphorylation of the transcriptional coactivator Yorkie (Yki)/YAP by Warts does not mediate the function of this pathway in promoting border cell migration, but rather provides negative feedback to limit the speed of migration. Instead, Warts phosphorylates and inhibits the actin regulator Ena to activate F-actin Capping protein activity on inner membranes and thereby restricts F-actin polymerization mainly to the outer rim of the migrating cluster.

The breathless FGF receptor homolog, a downstream target of Drosophila C/EBP in the developmental control of cell migration

Development ◽  
1995 ◽  
Vol 121 (8) ◽  
pp. 2255-2263 ◽  
Author(s):  
A.M. Murphy ◽  
T. Lee ◽  
C.M. Andrews ◽  
B.Z. Shilo ◽  
D.J. Montell
Keyword(s):  
Cell Migration ◽  
Molecular Mechanisms ◽  
Follicle Cells ◽  
Border Cells ◽  
Timely Initiation ◽  
Fgf Receptor ◽  
Border Cell ◽  
Downstream Target ◽  
Border Cell Migration ◽  
Factor C

To investigate the molecular mechanisms responsible for the temporal and spatial control of cell movements during development, we have been studying the migration of a small group of follicle cells, called the border cells, in the Drosophila ovary. Timely initiation of border cell migration requires the product of the slow border cells (slbo) locus, which encodes the Drosophila homolog of the transcription factor C/EBP. Here we report evidence that one target of C/EBP in the control of border cell migration is the FGF receptor homolog encoded by the breathless (btl) locus. btl expression in the ovary was border cell-specific, beginning just prior to the migration, and this expression was reduced in slbo mutants. btl mutations dominantly enhanced the border cell migration defects found in weak slbo alleles. Furthermore, C/EBP-independent btl expression was able to rescue the migration defects of hypomorphic slbo alleles. Purified Drosophila C/EBP bound eight sites in the btl 5′ flanking region by DNAse I footprinting. Taken together these results suggest that btl is a key, direct target for C/EBP in the regulation of border cell migration.

Jing: a downstream target of slbo required for developmental control of border cell migration

Development ◽  
2001 ◽  
Vol 128 (3) ◽  
pp. 321-330 ◽  
Author(s):  
Y. Liu ◽  
D.J. Montell
Keyword(s):  
Cell Migration ◽  
Leucine Zipper ◽  
Inducible Promoter ◽  
Regulatory Sequence ◽  
Border Cells ◽  
Border Cell ◽  
Downstream Target ◽  
Border Cell Migration ◽  
Factor C ◽  
Drosophila Ovary

Epithelial to mesenchymal transitions and cell migration are important features of embryonic development and tumor metastasis. We are employing a systematic genetic approach to study the border cells in the Drosophila ovary, as a simple model for these cellular behaviors. Previously we found that expression of the basic-region/leucine zipper transcription factor, C/EBP, is required for the border cells to initiate their migration. Here we report the identification of a second nuclear factor, named JING (which means ‘still’), that is required for initiation of border cell migration. The jing locus was identified in a screen for mutations that cause border cell migration defects in mosaic clones. The jing mutant phenotype resembles that of slbo mutations, which disrupt the Drosophila C/EBP gene, but is distinct from other classes of border cell migration mutants. Expression of a jing-lacZ reporter in border cells requires C/EBP. Moreover, expression of jing from a heat-inducible promoter rescues the border cell migration defects of hypomorphic slbo mutants. The JING protein is most closely related to a mouse protein, AEBP2, which was identified on the basis of its ability to bind a small regulatory sequence within the adipocyte AP2 gene to which mammalian C/EBP also binds. We propose that the need to coordinate cell differentiation with nutritional status may be the link between mammalian adipocytes and Drosophila border cells that led to the conservation of C/EBP and AEBP2.

scholarly journals DE-Cadherin Is Required for Intercellular Motility during Drosophila Oogenesis

1999 ◽  
Vol 144 (3) ◽  
pp. 533-547 ◽  
Author(s):  
Paulina Niewiadomska ◽  
Dorothea Godt ◽  
Ulrich Tepass
Keyword(s):  
Cell Migration ◽  
Follicle Cells ◽  
Epithelial Polarity ◽  
Border Cells ◽  
Drosophila Oogenesis ◽  
Animal Development ◽  
Border Cell ◽  
Germline Cells ◽  
Peripheral Cells ◽  
Homophilic Adhesion

Cadherins are involved in a variety of morphogenetic movements during animal development. However, it has been difficult to pinpoint the precise function of cadherins in morphogenetic processes due to the multifunctional nature of cadherin requirement. The data presented here indicate that homophilic adhesion promoted by Drosophila E-cadherin (DE-cadherin) mediates two cell migration events during Drosophila oogenesis. In Drosophila follicles, two groups of follicle cells, the border cells and the centripetal cells migrate on the surface of germline cells. We show that the border cells migrate as an epithelial patch in which two centrally located cells retain epithelial polarity and peripheral cells are partially depolarized. Both follicle cells and germline cells express DE-cadherin, and border cells and centripetal cells strongly upregulate the expression of DE-cadherin shortly before and during their migration. Removing DE-cadherin from either the follicle cells or the germline cells blocks migration of border cells and centripetal cells on the surface of germline cells. The function of DE-cadherin in border cells appears to be specific for migration as the formation of the border cell cluster and the adhesion between border cells are not disrupted in the absence of DE-cadherin. The speed of migration depends on the level of DE-cadherin expression, as border cells migrate more slowly when DE-cadherin activity is reduced. Finally, we show that the upregulation of DE-cadherin expression in border cells depends on the activity of the Drosophila C/EBP transcription factor that is essential for border cell migration.

Identification of mutations that cause cell migration defects in mosaic clones

Development ◽  
1999 ◽  
Vol 126 (9) ◽  
pp. 1869-1878 ◽  
Author(s):  
Y. Liu ◽  
D.J. Montell
Keyword(s):  
Cell Migration ◽  
Cell Motility ◽  
Hedgehog Signaling ◽  
Marker Gene ◽  
Cell Movement ◽  
Border Cells ◽  
Altered Expression ◽  
Border Cell ◽  
Recessive Mutations ◽  
Border Cell Migration

Cell movement is an important feature of animal development, wound healing and tumor metastasis; however, the mechanisms underlying cell motility remain to be elucidated. To further our understanding, it would be useful to identify all of the proteins that are essential for a cell to migrate, yet such information is not currently available for any cell type. We have carried out a screen for mutations affecting border cell migration in Drosophila. Mutations that cause defects in mosaic clones were identified, so that genes that are also required for viability could be detected. From 6000 mutagenized lines, 20 mutations on chromosome 2R were isolated that cause defects in border cell position. One of the mutations was dominant while all of the recessive mutations appeared to be homozygous lethal. This lethality was used to place the mutations into 16 complementation groups. Many of the mutations failed to complement cytologically characterized deficiencies, allowing their rapid mapping. Mutations in three loci altered expression of a marker gene in the border cells, whereas the remaining mutations did not. One mutation, which caused production of supernumerary border cells, was found to disrupt the costal-2 locus, indicating a role for Hedgehog signaling in border cell development. This screen identified many new loci required for border cell migration and our results suggest that this is a useful approach for elucidating the mechanisms involved in cell motility.

scholarly journals Tousled-like kinase regulates cytokine-mediated communication between cooperating cell types during collective border cell migration

2016 ◽  
Vol 27 (1) ◽  
pp. 12-19 ◽  
Author(s):  
Wenjuan Xiang ◽  
Dabing Zhang ◽  
Denise J. Montell
Keyword(s):  
Cell Migration ◽  
Cell Fate ◽  
Molecular Mechanisms ◽  
Metastatic Cancer ◽  
Cell Types ◽  
Collective Cell Migration ◽  
Border Cells ◽  
Border Cell ◽  
Stat Signaling ◽  
Border Cell Migration

Collective cell migration is emerging as a major contributor to normal development and disease. Collective movement of border cells in the Drosophila ovary requires cooperation between two distinct cell types: four to six migratory cells surrounding two immotile cells called polar cells. Polar cells secrete a cytokine, Unpaired (Upd), which activates JAK/STAT signaling in neighboring cells, stimulating their motility. Without Upd, migration fails, causing sterility. Ectopic Upd expression is sufficient to stimulate motility in otherwise immobile cells. Thus regulation of Upd is key. Here we report a limited RNAi screen for nuclear proteins required for border cell migration, which revealed that the gene encoding Tousled-like kinase (Tlk) is required in polar cells for Upd expression without affecting polar cell fate. In the absence of Tlk, fewer border cells are recruited and motility is impaired, similar to inhibition of JAK/STAT signaling. We further show that Tlk in polar cells is required for JAK/STAT activation in border cells. Genetic interactions further confirmed Tlk as a new regulator of Upd/JAK/STAT signaling. These findings shed light on the molecular mechanisms regulating the cooperation of motile and nonmotile cells during collective invasion, a phenomenon that may also drive metastatic cancer.

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