Davidson LA (2012) BMC Biol "No strings attached: new insights into epithelial morphogenesis."

Davidson LA

[BMC Biol, 2012]

The dramatic ingression of tissue sheets that accompanies many morphogenetic processes, most notably gastrulation, has been largely attributed to contractile circum-apical actomyosin 'purse-strings' in the infolding cells. Recent studies, however, including one in BMC Biology, expose mechanisms that rely less on actomyosin contractility of purse-string bundles and more on dynamics in the global cortical actomyosin network of the cells. These studies illustrate how punctuated actomyosin contractions and flow of these networks can remodel both epithelial and planarly organized mesenchymal sheets.

Felix MA et al. (2002) Hermann, Editeurs des Sciences et des Arts. Paris, France. "Caenorhabditis elegans. Un organisme modele en biologie."

Labouesse M, Segalat L, Felix MA

[Hermann, Editeurs des Sciences et des Arts. Paris, France., 2002]

L'espce Caenorhabditis elegans fut dcrite en 1900 Alger par E. Maupas, qui s'intressait son mode de reproduction hermaphrodite. Plus tard, vers le milieu du vingtime sicle, V. Nigon et ses collaboratuers Lyon tudirent les reorganizations cellulaires accompagnant la fecundation et les premiers clivages. J. Brun isola les preiers mutants morpholgiques.

Davidson EH et al. (1999) J Exp Zool "Themes from a NASA workshop on gene regulatory processes in development and evolution."

Davidson EH, Ruvkun GB

[J Exp Zool, 1999]

A memorable workshop, focused on causal mechanisms in metazoan evolution and sponsored by NASA, was held in early June 1998, at MBL. The workshop was organized by Mike Levine and Eric H. Davidson, and it included the PI and associates from 12 different laboratories, a total of about 30 people. Each laboratory had about two and one half hours in which to represent its recent research and cast up its current ideas for an often intense discussion. In the following we have tried to enunciate some of the major themes that emerged, and to reflect on their implications. The opinions voiced are our own. We would like to tender apologies over those contributions we have not been able to include, but this is not, strictly speaking, a meeting review. Rather we have focused on those topics that bear more directly on evolutionary mechanisms, and have therefore slighted some presentations (including some of our own), that were oriented mainly toward developmental processes. J. Exp. Zool. (Mol. Dev. Evol. ) 285:104-115, 1999.

Klass MR (1986) International Review of Cytology "Cell-specific gene expression in the nematode."

Klass MR

[International Review of Cytology, 1986]

The problem of cell-specific gene expression has long been a major concern to developmental biologists. Why and how specific genes are expressed only in certain differentiated cells and not in others are of vital importance. Many well-documented examples of differentiated cell types expressing quantitative and/or qualitative changes in gene expression now exist. For example, Galau et al. (1976) demonstrated that different sets of genes are expressed during development and in different adult tissues of the sea urchin. More recently, Angerer and Davidson (1984) have used in situ hybridization of specific DNA probes to demonstrate the expression of lineage-specific genes long before morphological differentiation. Other examples include the ovalbumin gene, known to be expressed only in hormone-stimulated oviducts, and the globin genes expressed at various developmental stages in differentiating erythrocytes. Many other examples of cell-specific gene expression are known, including the silk moth chorion proteins, the glue proteins in Drosophila, and a-amylase in mammals. Detailed molecular analysis of genes has provided important information on the mechanisms of gene expression. For example, numerous studies have examined the role of chromatin structure as well as the significance of specific sequences in the transcription and translation of eukaryotic genes. Furthermore, studies of the globin, actin, immunoglobulin, histone, and silk moth chorion genes have demonstrated the existence of gene families with suggested importance for the evolution of new functions for old genes. In addition, the detailed study of multigene families has provided vital information on the mechanisms of cell-specific gene expression as seen, for example, in the temporal and spatial regulation of different members of the actin gene family....

Aschner M et al. (2017) Metallomics "Imaging metals in Caenorhabditis elegans."

Bornhorst J, Sperling M, Schwerdtle T, Karst U, Palinski C, Aschner M

[Metallomics, 2017]

Systemic trafficking and storage of essential metal ions play fundamental roles in living organisms by serving as essential cofactors in various cellular processes. Thereby metal quantification and localization are critical steps in understanding metal homeostasis, and how their dyshomeostasis might contribute to disease etiology and the ensuing pathologies. Furthermore, the amount and distribution of metals in organisms can provide insight into their underlying mechanisms of toxicity and toxicokinetics. While in vivo studies on metal imaging in mammalian experimental animals are complex, time- and resource-consuming, the nematode Caenorhabditis elegans (C. elegans) provides a suitable comparative and complementary model system. Expressing homologous genes to those inherent to mammals, including those that regulate metal homeostasis and transport, C. elegans has become a powerful tool to study metal homeostasis and toxicity. A number of recent technical advances have been made in the development and application of analytical methods to visualize metal ions in C. elegans. Here, we briefly summarize key findings and challenges of the three main techniques and their application to the nematode, namely sensing fluorophores, microbeam synchrotron radiation X-ray fluorescence as well as laser ablation (LA) coupled to inductively coupled plasma-mass spectrometry (ICP-MS).