Gan WJ et al. (2020) Front Cell Dev Biol "Mechanochemical Control of Symmetry Breaking in the Caenorhabditis elegans Zygote."

Gan WJ, Motegi F

[Front Cell Dev Biol, 2020]

Cell polarity is the asymmetric organization of cellular components along defined axes. A key requirement for polarization is the ability of the cell to break symmetry and achieve a spatially biased organization. Despite different triggering cues in various systems, symmetry breaking (SB) usually relies on mechanochemical modulation of the actin cytoskeleton, which allows for advected movement and reorganization of cellular components. Here, the mechanisms underlying SB in <i>Caenorhabditis elegans</i> zygote, one of the most popular models to study cell polarity, are reviewed. A zygote initiates SB through the centrosome, which modulates mechanics of the cell cortex to establish advective flow of cortical proteins including the actin cytoskeleton and partitioning defective (PAR) proteins. The chemical signaling underlying centrosomal control of the Aurora A kinase-mediated cascade to convert the organization of the contractile actomyosin network from an apolar to polar state is also discussed.

Clarke ND et al. (1998) Science "Zinc fingers in Caenorhabditis elegans: finding families and probing pathways."

Berg JM, Clarke ND

[Science, 1998]

More than 3 percent of the protein sequences inferred from the Caenorhabditis elegans genome contain sequence motifs characteristic of zinc-binding structural domains, and of these more than half are believed to be sequence-specific DNA-binding proteins. The distribution of these zinc-binding domains among the genomes of various organisms offers insights into the role of zinc-binding proteins in evolution. In addition, the complete genome sequence of C. elegans provides an opportunity to analyze, and perhaps predict, pathways of transcriptional regulation.AD - Department of Biophysics and Biophysical Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.FAU - Clarke, N DAU - Clarke NDFAU - Berg, J MAU - Berg JMLA - engPT - Journal ArticlePT - ReviewPT - Review, TutorialCY - UNITED STATESTA - ScienceJID - 0404511RN - 0 (DNA-Binding Proteins)RN - 0 (Helminth Proteins)RN - 0 (Membrane Proteins)RN - 0 (Receptors, Cell Surface)RN - 0 (Trans-Activators)RN - 0 (Transcription Factors)RN - 0 (erythroid-like transcription factor 1)RN - 0 (tra-1 protein, Caenorhabditis elegans)SB - IM

Ruvkun GB et al. (1998) Science "The taxonomy of developmental control in Caenorhabditis elegans."

Ruvkun GB, Hobert O

[Science, 1998]

The Caenorhabditis elegans genome sequence was surveyed for transcription factor and signaling gene families that have been shown to regulate development in a variety of species. About 10 to 25 percent of the genes in most of the gene families already have been genetically analyzed in C. elegans, about half of the genes detect probable orthologs in other species, and about 10 to 25 percent of the genes are, at present, unique to C. elegans. Caenorhabditis elegans is also missing genes that are found in vertebrates and other invertebrates. Thus the genome sequence reveals universals in developmental control that are the legacy of metazoan complexity before the Cambrian explosion, as well as genes that have been more recently invented or lost in particular phylogenetic lineages.AD - Department of Molecular Biology, Massachusetts General Hospital, Department of Genetics, Harvard Medical School, Boston, MA 02114, USA. ruvkun@frodo.mgh.harvard.eduFAU - Ruvkun, GAU - Ruvkun GFAU - Hobert, OAU - Hobert OLA - engPT - Journal ArticlePT - ReviewPT - Review, TutorialCY - UNITED STATESTA - ScienceJID - 0404511RN - 0 (Helminth Proteins)RN - 0 (Transcription Factors)SB - IM

Wilson C et al. (2022) Front Cell Dev Biol "Perspectives on Mechanisms Supporting Neuronal Polarity From Small Animals to Humans."

Wilson C, Caceres A, Moyano AL

[Front Cell Dev Biol, 2022]

Axon-dendrite formation is a crucial milestone in the life history of neurons. During this process, historically referred as "the establishment of polarity," newborn neurons undergo biochemical, morphological and functional transformations to generate the axonal and dendritic domains, which are the basis of neuronal wiring and connectivity. Since the implementation of primary cultures of rat hippocampal neurons by Gary Banker and Max Cowan in 1977, the community of neurobiologists has made significant achievements in decoding signals that trigger axo-dendritic specification. External and internal cues able to switch on/off signaling pathways controlling gene expression, protein stability, the assembly of the polarity complex (i.e., PAR3-PAR6-aPKC), cytoskeleton remodeling and vesicle trafficking contribute to shape the morphology of neurons. Currently, the culture of hippocampal neurons coexists with alternative model systems to study neuronal polarization in several species, from single-cell to whole-organisms. For instance, <i>in vivo</i> approaches using <i>C. elegans</i> and <i>D. melanogaster,</i> as well as <i>in situ</i> imaging in rodents, have refined our knowledge by incorporating new variables in the polarity equation, such as the influence of the tissue, glia-neuron interactions and three-dimensional development. Nowadays, we have the unique opportunity of studying neurons differentiated from human induced pluripotent stem cells (hiPSCs), and test hypotheses previously originated in small animals and propose new ones perhaps specific for humans. Thus, this article will attempt to review critical mechanisms controlling polarization compiled over decades, highlighting points to be considered in new experimental systems, such as hiPSC neurons and human brain organoids.