scholarly journals Latrophilin Signaling Links Anterior-Posterior Tissue Polarity and Oriented Cell Divisions in the C. elegans Embryo

2009 ◽  
Vol 17 (4) ◽  
pp. 494-504 ◽  
Author(s):  
Tobias Langenhan ◽  
Simone Prömel ◽  
Lamia Mestek ◽  
Behrooz Esmaeili ◽  
Helen Waller-Evans ◽  
...  
Keyword(s):  
Tissue Polarity ◽  
C Elegans ◽  
Cell Divisions ◽  
Anterior Posterior

Multiple levels of regulation specify the polarity of an asymmetric cell division in C. elegans

Development ◽  
2000 ◽  
Vol 127 (21) ◽  
pp. 4587-4598 ◽  
Author(s):  
J. Whangbo ◽  
J. Harris ◽  
C. Kenyon
Keyword(s):  
Cell Division ◽  
Wnt Signaling ◽  
Epidermal Cell ◽  
Asymmetric Cell Division ◽  
Asymmetric Cell Divisions ◽  
Signaling Systems ◽  
Tissue Polarity ◽  
C Elegans ◽  
Cell Divisions ◽  
A Cell

Wnt signaling systems play important roles in the generation of cell and tissue polarity during development. We describe a Wnt signaling system that acts in a new way to orient the polarity of an epidermal cell division in C. elegans. In this system, the EGL-20/Wnt signal acts in a permissive fashion to polarize the asymmetric division of a cell called V5. EGL-20 regulates this polarization by counteracting lateral signals from neighboring cells that would otherwise reverse the polarity of the V5 cell division. Our findings indicate that this lateral signaling pathway also involves Wnt pathway components. Overexpression of EGL-20 disrupts both the asymmetry and polarity of lateral epidermal cell divisions all along the anteroposterior (A/P) body axis. Together our findings suggest that multiple, inter-related Wnt signaling systems may act together to polarize asymmetric cell divisions in this tissue.

scholarly journals Interactions between the WEE-1.3 kinase and the PAM-1 aminopeptidase in oocyte maturation and the early C. elegans embryo

2021 ◽  
Author(s):  
Dorothy Benton ◽  
Eva C Jaeger ◽  
Arielle Kilner ◽  
Ashley Kimble ◽  
Josh Lowry ◽  
...  
Keyword(s):  
Missense Mutation ◽  
Oocyte Maturation ◽  
Protective Role ◽  
C Elegans ◽  
Direct Target ◽  
The One ◽  
Actomyosin Cytoskeleton ◽  
Embryonic Viability ◽  
Anterior Posterior

Abstract Puromycin-sensitive aminopeptidases are found across phyla and are known to regulate the cell-cycle and play a protective role in neurodegenerative disease. PAM-1 is a puromycin-sensitive aminopeptidase important for meiotic exit and polarity establishment in the one-cell Caenorhabditis elegans embryo. Despite conservation of this aminopeptidase, little is known about its targets during development. In order to identify novel interactors, we conducted a suppressor screen and isolated four suppressing mutations in three genes that partially rescued the maternal-effect lethality of pam-1 mutants. Suppressed strains show improved embryonic viability and polarization of the anterior-posterior axis. We identified a missense mutation in wee-1.3 in one of these suppressed strains. WEE-1.3 is an inhibitory kinase that regulates maturation promoting factor. While the missense mutation suppressed polarity phenotypes in pam-1, it does so without restoring centrosome-cortical contact or altering the cortical actomyosin cytoskeleton. To see if PAM-1 and WEE-1.3 interact in other processes, we examined oocyte maturation. While depletion of wee-1.3 causes sterility due to precocious oocyte maturation, this effect was lessened in pam-1 worms, suggesting that PAM-1 and WEE-1.3 interact in this process. Levels of WEE-1.3 were comparable between wild-type and pam-1 strains, suggesting that WEE-1.3 is not a direct target of the aminopeptidase. Thus, we have established an interaction between PAM-1 and WEE-1.3 in multiple developmental processes and have identified suppressors that are likely to further our understanding of the role of puromycin-sensitive aminopeptidases during development.

The role of lin-22, a hairy/enhancer of split homolog, in patterning the peripheral nervous system of C. elegans

Development ◽  
1997 ◽  
Vol 124 (15) ◽  
pp. 2875-2888 ◽  
Author(s):  
L.A. Wrischnik ◽  
C.J. Kenyon
Keyword(s):  
Stem Cell ◽  
Regulatory Gene ◽  
Epidermal Cells ◽  
Body Axis ◽  
Wild Type ◽  
Hox Gene ◽  
C Elegans ◽  
Cell Divisions ◽  
Body Regions ◽  
Stem Cell Divisions

In C. elegans, six lateral epidermal stem cells, the seam cells V1-V6, are located in a row along the anterior-posterior (A/P) body axis. Anterior seam cells (V1-V4) undergo a fairly simple sequence of stem cell divisions and generate only epidermal cells. Posterior seam cells (V5 and V6) undergo a more complicated sequence of cell divisions that include additional rounds of stem cell proliferation and the production of neural as well as epidermal cells. In the wild type, activity of the gene lin-22 allows V1-V4 to generate their normal epidermal lineages rather than V5-like lineages. lin-22 activity is also required to prevent additional neurons from being produced by one branch of the V5 lineage. We find that the lin-22 gene exhibits homology to the Drosophila gene hairy, and that lin-22 activity represses neural development within the V5 lineage by blocking expression of the posterior-specific Hox gene mab-5 in specific cells. In addition, in order to prevent anterior V cells from generating V5-like lineages, wild-type lin-22 gene activity must inhibit (directly or indirectly) at least five downstream regulatory gene activities. In anterior body regions, lin-22(+) inhibits expression of the Hox gene mab-5. It also inhibits the activity of the achaete-scute homolog lin-32 and an unidentified gene that we postulate regulates stem cell division. Each of these three genes is required for the expression of a different piece of the ectopic V5-like lineages generated in lin-22 mutants. In addition, lin-22 activity prevents two other Hox genes, lin-39 and egl-5, from acquiring new activities within their normal domains of function along the A/P body axis. Some, but not all, of the patterning activities of lin-22 in C. elegans resemble those of hairy in Drosophila.

scholarly journals pop-1/TCF, ref-2/ZIC and T-box factors regulate the development of anterior cells in the C. elegans embryo

2021 ◽  
Author(s):  
Jonathan D Rumley ◽  
Elicia A Preston ◽  
Dylan Cook ◽  
Felicia L Peng ◽  
Amanda L Zacharias ◽  
...  
Keyword(s):  
Wnt Pathway ◽  
Expression Patterns ◽  
Specific Expression ◽  
T Box ◽  
Animal Development ◽  
C Elegans ◽  
The Many ◽  
Necessary And Sufficient ◽  
Cell Division Timing ◽  
Anterior Posterior

Patterning of the anterior-posterior axis is fundamental to animal development. The Wnt pathway plays a major role in this process by activating the expression of posterior genes in animals from worms to humans. This observation raises the question of whether the Wnt pathway or other regulators control the expression of the many anterior-expressed genes. We found that the expression of five anterior-specific genes in Caenorhabditis elegans embryos depends on the Wnt pathway effectors pop-1/TCF and sys-1/β-catenin. We focused further on one of these anterior genes, ref-2/ZIC, a conserved transcription factor expressed in multiple anterior lineages. Live imaging of ref-2 mutant embryos identified defects in cell division timing and position in anterior lineages. Cis-regulatory dissection identified three ref-2 transcriptional enhancers, one of which is necessary and sufficient for anterior-specific expression. This enhancer is activated by the T-box transcription factors TBX-37 and TBX-38, and surprisingly, concatemerized TBX-37/38 binding sites are sufficient to drive anterior-biased expression alone, despite the broad expression of TBX-37 and TBX-38. Taken together, our results highlight the diverse mechanisms used to regulate anterior expression patterns in the embryo.

Specification of anterior-posterior differences within the AB lineage in the C. elegans embryo: a polarising induction

Development ◽  
1995 ◽  
Vol 121 (5) ◽  
pp. 1559-1568 ◽  
Author(s):  
H. Hutter ◽  
R. Schnabel
Keyword(s):  
Cell Fate ◽  
Tissue Type ◽  
Cell Stage ◽  
Anterior Portion ◽  
Developmental Potential ◽  
C Elegans ◽  
The Third ◽  
Inductive Signal ◽  
Anterior Posterior ◽  
Lineage Analysis

In a C. elegans embryo the third cleavages of descendants of the anterior blastomere AB of the 2-cell stage create pairs of blastomeres that develop differently. By laser ablation experiments we show that the fates of all the posterior daughters of this division depend on an induction occurring three cleavages before these blastomeres are born. The time of induction precludes a direct effect on cell fate. Alternatively, we suggest that the induction creates a heritable cell polarity which is propagated through several divisions. We suggest a model to demonstrate how a signal could be propagated through several rounds of cell division. An important implication of our observations is that this early induction acts to specify blastomere identity, not tissue type. A detailed lineage analysis revealed that altering the inductive signal alters complex lineage patterns as a whole. The induction described here, together with two inductions described previously can be used to illustrate how the anterior portion of the C. elegans embryo can be successively subdivided into blastomeres with unique developmental potential.

C. elegans POP-1/TCF functions in a canonical Wnt pathway that controls cell migration and in a noncanonical Wnt pathway that controls cell polarity

Development ◽  
2001 ◽  
Vol 128 (4) ◽  
pp. 581-590 ◽  
Author(s):  
M. Herman
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Polarity ◽  
Wnt Pathway ◽  
Beta Catenin ◽  
Wild Type ◽  
C Elegans ◽  
Cell Divisions ◽  
Canonical Wnt Pathway ◽  
Canonical Wnt

In Caenorhabditis elegans, Wnt signaling pathways are important in controlling cell polarity and cell migrations. In the embryo, a novel Wnt pathway functions through a (beta)-catenin homolog, WRM-1, to downregulate the levels of POP-1/Tcf in the posterior daughter of the EMS blastomere. The level of POP-1 is also lower in the posterior daughters of many anteroposterior asymmetric cell divisions during development. I have found that this is the case for of a pair of postembryonic blast cells in the tail. In wild-type animals, the level of POP-1 is lower in the posterior daughters of the two T cells, TL and TR. Furthermore, in lin-44/Wnt mutants, in which the polarities of the T cell divisions are frequently reversed, the level of POP-1 is frequently lower in the anterior daughters of the T cells. I have used a novel RNA-mediated interference technique to interfere specifically with pop-1 zygotic function and have determined that pop-1 is required for wild-type T cell polarity. Surprisingly, none of the three C. elegans (beta)-catenin homologs appeared to function with POP-1 to control T cell polarity. Wnt signaling by EGL-20/Wnt controls the migration of the descendants of the QL neuroblast by regulating the expression the Hox gene mab-5. Interfering with pop-1 zygotic function caused defects in the migration of the QL descendants that mimicked the defects in egl-20/Wnt mutants and blocked the expression of mab-5. This suggests that POP-1 functions in the canonical Wnt pathway to control QL descendant migration and in novel Wnt pathways to control EMS and T cell polarities.

Sign in / Sign up

Export Citation Format

Share Document