scholarly journals Mutations in the Caenorhabditis elegans Gene vab-3 Reveal Distinct Roles in Fate Specification and Unequal Cytokinesis in an Asymmetric Cell Division

1995 ◽  
Vol 170 (2) ◽  
pp. 679-689 ◽  
Author(s):  
Helen M. Chamberlin ◽  
Paul W. Sternberg
Keyword(s):  
Cell Division ◽  
Caenorhabditis Elegans ◽  
Asymmetric Cell Division ◽  
Fate Specification

scholarly journals Roles of Actin in the Morphogenesis of the Early Caenorhabditis elegans Embryo

2020 ◽  
Vol 21 (10) ◽  
pp. 3652
Author(s):  
Dureen Samandar Eweis ◽  
Julie Plastino
Keyword(s):  
Cell Division ◽  
Caenorhabditis Elegans ◽  
Asymmetric Cell Division ◽  
Cell Types ◽  
Actin Dynamics ◽  
Actin Binding ◽  
Asymmetric Cell Divisions ◽  
C Elegans ◽  
Asymmetric Divisions ◽  
Different Cell Types

The cell shape changes that ensure asymmetric cell divisions are crucial for correct development, as asymmetric divisions allow for the formation of different cell types and therefore different tissues. The first division of the Caenorhabditis elegans embryo has emerged as a powerful model for understanding asymmetric cell division. The dynamics of microtubules, polarity proteins, and the actin cytoskeleton are all key for this process. In this review, we highlight studies from the last five years revealing new insights about the role of actin dynamics in the first asymmetric cell division of the early C. elegans embryo. Recent results concerning the roles of actin and actin binding proteins in symmetry breaking, cortical flows, cortical integrity, and cleavage furrow formation are described.

scholarly journals MAP Kinase Signaling Antagonizes PAR-1 Function During Polarization of the Early Caenorhabditis elegans Embryo

Genetics ◽  
2009 ◽  
Vol 183 (3) ◽  
pp. 965-977 ◽  
Author(s):  
Annina C. Spilker ◽  
Alexia Rabilotta ◽  
Caroline Zbinden ◽  
Jean-Claude Labbé ◽  
Monica Gotta
Keyword(s):  
Cell Division ◽  
Caenorhabditis Elegans ◽  
Map Kinase ◽  
Cell Fate ◽  
Asymmetric Cell Division ◽  
Asymmetric Distribution ◽  
Kinase Signaling ◽  
C Elegans ◽  
Link Type ◽  
Map Kinase Signaling

PAR proteins (partitioning defective) are major regulators of cell polarity and asymmetric cell division. One of the par genes, par-1, encodes a Ser/Thr kinase that is conserved from yeast to mammals. In Caenorhabditis elegans, par-1 governs asymmetric cell division by ensuring the polar distribution of cell fate determinants. However the precise mechanisms by which PAR-1 regulates asymmetric cell division in C. elegans remain to be elucidated. We performed a genomewide RNAi screen and identified six genes that specifically suppress the embryonic lethal phenotype associated with mutations in par-1. One of these suppressors is mpk-1, the C. elegans homolog of the conserved mitogen activated protein (MAP) kinase ERK. Loss of function of mpk-1 restored embryonic viability, asynchronous cell divisions, the asymmetric distribution of cell fate specification markers, and the distribution of PAR-1 protein in par-1 mutant embryos, indicating that this genetic interaction is functionally relevant for embryonic development. Furthermore, disrupting the function of other components of the MAPK signaling pathway resulted in suppression of par-1 embryonic lethality. Our data therefore indicates that MAP kinase signaling antagonizes PAR-1 signaling during early C. elegans embryonic polarization.

scholarly journals The Role of Cytoplasmic MEX-5/6 Polarity in Asymmetric Cell Division

2021 ◽  
Vol 83 (4) ◽  
Author(s):  
Sungrim Seirin-Lee
Keyword(s):  
Mathematical Model ◽  
Cell Division ◽  
Caenorhabditis Elegans ◽  
Cell Membrane ◽  
Mother Cell ◽  
Asymmetric Cell Division ◽  
Transmembrane Protein ◽  
Cytoplasmic Protein ◽  
Cell Geometry

AbstractIn the process of asymmetric cell division, the mother cell induces polarity in both the membrane and the cytosol by distributing substrates and components asymmetrically. Such polarity formation results from the harmonization of the upstream and downstream polarities between the cell membrane and the cytosol. MEX-5/6 is a well-investigated downstream cytoplasmic protein, which is deeply involved in the membrane polarity of the upstream transmembrane protein PAR in the Caenorhabditis elegans embryo. In contrast to the extensive exploration of membrane PAR polarity, cytoplasmic polarity is poorly understood, and the precise contribution of cytoplasmic polarity to the membrane PAR polarity remains largely unknown. In this study, we explored the interplay between the cytoplasmic MEX-5/6 polarity and the membrane PAR polarity by developing a mathematical model that integrates the dynamics of PAR and MEX-5/6 and reflects the cell geometry. Our investigations show that the downstream cytoplasmic protein MEX-5/6 plays an indispensable role in causing a robust upstream PAR polarity, and the integrated understanding of their interplay, including the effect of the cell geometry, is essential for the study of polarity formation in asymmetric cell division.

scholarly journals KIF18B is a cell-type specific regulator of spindle orientation in the epidermis

2021 ◽  
pp. mbc.E21-06-0291
Author(s):  
Rebecca S. Moreci ◽  
Terry Lechler
Keyword(s):  
Cell Division ◽  
Hair Follicle ◽  
Cell Fate ◽  
Asymmetric Cell Division ◽  
Microtubule Dynamics ◽  
Spindle Orientation ◽  
Cell Cortex ◽  
Cell Fate Specification ◽  
Cell Fate Decisions ◽  
Fate Specification

Proper spindle orientation is required for asymmetric cell division and the establishment of complex tissue architecture. In the developing epidermis, spindle orientation requires a conserved cortical protein complex of LGN/NuMA/dynein-dynactin. However, how microtubule dynamics are regulated to interact with this machinery and properly position the mitotic spindle is not fully understood. Furthermore, our understanding of the processes that link spindle orientation during asymmetric cell division to cell fate specification in distinct tissue contexts remains incomplete. We report a role for the microtubule catastrophe factor KIF18B in regulating microtubule dynamics to promote spindle orientation in keratinocytes. During mitosis, KIF18B accumulates at the cell cortex, colocalizing with the conserved spindle orientation machinery. In vivo we find that KIF18B is required for oriented cell divisions within the hair placode, the first stage of hair follicle morphogenesis, but is not essential in the interfollicular epidermis. Disrupting spindle orientation in the placode, using mutations in either KIF18B or NuMA, results in aberrant cell fate marker expression of hair follicle progenitor cells. These data functionally link spindle orientation to cell fate decisions during hair follicle morphogenesis. Taken together, our data demonstrate a role for regulated microtubule dynamics in spindle orientation in epidermal cells. This work also highlights the importance of spindle orientation during asymmetric cell division to dictate cell fate specification. [Media: see text] [Media: see text]

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