Richard, Victoria et al. (2021) International Worm Meeting "Coordinating neuronal signaling pathways with anterior epidermal cell migration"

Grimbert, Stephanie, Richard, Victoria, Piekny, Alisa, Mastronardi, Karina

[International Worm Meeting, 2021]

We study the cell patterning that regulates anterior morphogenesis in C. elegans embryos. We recently described how the epidermal, pharyngeal and neuroblast cells must be properly coordinated for development of the anterior lumen. However, the signaling events that coordinate these cell types are still not well understood. We found that soon after the ventral epidermal cells meet at the ventral midline, PAR-6 (polarity protein) foci associated with different subsets of cells form distinct patterns in the anterior of the embryo. Specifically, we observed two pentagons, a larger focal point and a more ventrally positioned semi-circle of foci. While the larger focal point corresponds to the arcade cells (anterior most cells of the pharynx), the pentagons appear to correspond to neuronal precursor and/or glial cells (UNC-119, MIR-228), while the semi-circle of foci may correspond to neuronal precursor cells (UNC-119, HLH-16), although some of these could come from the epidermis. The dorsal foci within each pentagon move in concert with the dorsal epidermal cells, while the semi-circle of foci move with the ventral epidermal cells. Ventral epidermal cells migrate using F-actin-rich projections, and we observed that these projections come close to, but do not cross the semi-circle of foci suggesting they are guided by nearby cues. We found that blocking neuroblast cell division and disrupting the PAR-6 patterns caused delays in epidermal cell migration by decreasing the number of F-actin projections. Based on these findings, we propose that signals associated with the neuronal and/or glial cells control anterior epidermal cell migration. To identify these signals, we are performing tissue-specific RNAi to guidance cues and their receptors including ephrins (enf-1/2/3), netrin (unc-6), slit (slt-1) and sax/robo (sax-3), as well as Wnt (lin-44 , mom-2, mig-5, etc), and determining how they disrupt either 1) the pentagon or semi-circle of foci and/or, 2) migration of the anterior epidermal cells. This work will continue to provide new insights on the mechanisms underlying the multi-tissue cooperation required for successful anterior morphogenesis of C. elegans embryos.

Townsend SR et al. (1994) Worm Breeder's Gazette "C. elegans Molecular Genetics and Long PCR."

Finelli AL, Savage C, Xie T, Padgett RW, Townsend SR

[Worm Breeder's Gazette, 1994]

C. elegans Molecular Genetics and Long PCR Scott R. Townsend, Cathy Savage, Alyce L. Finelli, Ting Xie, and Richard W. Padgett, Waksman Institute and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ 08855

Chalfie M et al. (1994) Science "Green fluorescent protein as a marker for gene expression."

Euskirchen G, Tu Y, Chalfie M, Prasher DC, Ward WW

[Science, 1994]

A complementary DNA for the Aequorea victoria green fluorescent protein (GFP) produces a fluorescent product when expressed in prokaryotic (Escherichia coli) or eukaryotic (Caenorhabditis elegans) cells. Because exogenous substrates and cofactors are not required for this fluorescence, GFP expression can be used to monitor gene expression and protein localization in living organisms.

Grimbert, Stephanie et al. (2021) International Worm Meeting "C. elegans Anterior Morphogenesis: A Tale of Three Tissues"

Piekny, Alisa, Grimbert, Stephanie, Mastronardi, Karina, Richard, Victoria

[International Worm Meeting, 2021]

Morphogenesis encompasses the biological events driving tissue and organ development. The need to build tissues with precision relies on the spatiotemporal coordination of cell shape changes, migration and adhesion. As complex structures are derived from multiple tissue types, studying their organization in vivo is essential for a comprehensive understanding and yet is extremely challenging. In this study we show how cells from three different tissues are coordinated to give rise to the anterior lumen. While most aspects of epidermal morphogenesis and several aspects of pharyngeal morphogenesis have been well-described in C. elegans, it is less clear how cells from the pharynx, epidermis and neuroblasts coordinate to define the location of the anterior lumen and supporting structures. Using various microscopy and software approaches, we found that interactions between pharyngeal, epidermal and neuronal cells are required for anterior morphogenesis. Specifically, to define the position and timing of the anterior lumen and future mouth of the worm. We characterized the movements and patterns of these three cell types and defined key events associated with anterior morphogenesis. We found that the first visible marker of the location of the future anterior lumen is provided by projections from the anterior-most pharyngeal cells (arcade cells) and facilitates patterning of the surrounding neuroblasts. These neuroblasts organize into distinct patterns which subsequently influences the rate of epidermal cell migration towards the anterior. Conversely, the epidermal cells ultimately reinforce the position of the future lumen, as they must join with the pharyngeal cells for their successful epithelialization. We described the crucial involvement of junction (HMP-1, AJM-1), polarity (PAR-6 and PAR-3) and contractility (NMY-2) proteins in this precise patterning. Thus, we have established an innovative model system to explore the in-depth molecular regulation of these different patterns and interactions between multiple cell-types.

Martinelli SD et al. (1995) International C. elegans Meeting "ACEDB"

Durbin RM, Martinelli SD

[International C. elegans Meeting, 1995]

We hope to provide a demonstration of the current state of the ACeDB worm database on Unix workstations, and if possible Apple Macintosh, throughout the poster sessions. This will be based on the new version 4 release of the acedb software (Jean Thierry-Mieg, Richard Durbin and numerous others), which contains many new features for greater efficiency, more flexible printing, and display of new features.

(2024) Development "The people behind the papers - Thomas Mullan and Richard Poole."

[Development, 2024]

Asymmetric cell divisions can produce daughter cells of different sizes, but it is unclear whether unequal cell cleavage is important for cell fate decisions. A new paper in Development explores the role of unequal cleavages in Caenorhabditis elegans embryos. To learn more about the story behind the paper, we caught up with first author Thomas Mullan and corresponding author Richard Poole, Associate Professor of Developmental Biology at University College London, UK.

Herman RK et al. (1997) Worm Breeder's Gazette "STATUS OF THE CAENORHABDITIS GENETICS CENTER (CGC)"

Herman RK, Stiernagle TL

[Worm Breeder's Gazette, 1997]

May 31, 1997 will mark the end of our current five-year contract with the NIH National Center for Research Resources, which supports the activities of the CGC. The activities in St. Paul have involved primarily the acquisition, maintenance and distribution of stocks and information about stocks, acquisition and maintenance of the C. elegans bibliography, and publication and distribution of The Worm Breeder's Gazette (WBG) and WBG Subscriber Directory. Genetic nomenclature and the genetic map have been managed for the period 1992-1997 by Jonathan Hodgkin (CGC Map Curator) on a subcontract. Currently, the subcontract provides half of Sylvia Martinelli's salary, plus travel and minor expenses. Additional support from within the MRC Laboratory of Molecular Biology and the Sanger Centre has been used to fund other essential resources such as computer equipment, as well as Jonathan's and Richard Durbin's time. Richard has been involved in mapkeeping through his work on ACeDB. We are pleased that Jonathan, Richard and Sylvia agreed to continue their work for another five years. We have submitted an application for a new five year contract that would include a subcontract for nomenclature and mapkeeping on essentially the same terms as before. A description of the nomenclature and mapkeeping activities is given in the following abstract. We are grateful to Leon Avery for setting up our CGC gopher server and also for arranging for the electronic submission of WBG abstracts (as well as abstracts for various C. elegans meetings). His C. elegans WWW server has become an essential resource for the worm community. We were therefore pleased to include Leon (only 5% effort) in a second subcontract as part of our new CGC application. We welcome comments and suggestions about any of the CGC activities.

Kelley S (2000) Brief Bioinform "Getting started with Acedb."

Kelley S

[Brief Bioinform, 2000]

Acedb is one of the more venerable pieces of Genomics software. Acedb was originally created in 1992 by Richard Durbin and Jean Thierry-Mieg to manage the data from the Caenorhabditis elegans mapping project and subsequently the C. elegans sequencing project. From beginnings as a C. elegans-specific tool, it has been continuously developed into a flexible suite of data management, display and scripting tools providing facilities for managing and annotation mapping information and DNA and peptide sequences.This paper gives a basic overview of the Acedb suite, and step-by-step guidance on how to download and install Acedb. It is intended to take an Acedb novice to stage where they can begin to experiment and explore the facilities that are available.

Sommer RJ (2008) Bioessays "Homology and the hierarchy of biological systems."

Sommer RJ

[Bioessays, 2008]

Homology is the similarity between organisms due to common ancestry. Introduced by Richard Owen in 1843 in a paper entitled "Lectures on comparative anatomy and physiology of the invertebrate animals", the concept of homology predates Darwin's "Origin of Species" and has been very influential throughout the history of evolutionary biology. Although homology is the central concept of all comparative biology and provides a logical basis for it, the definition of the term and the criteria of its application remain controversial. Here, I will discuss homology in the context of the hierarchy of biological organization. I will provide insights gained from an exemplary case study in evolutionary developmental biology that indicates the uncoupling of homology at different levels of biological organization. I argue that continuity and hierarchy are separate but equally important issues of homology.

Consortium Wormbase et al. (2000) West Coast Worm Meeting "From ACeDB to a more complete and usable database"

Consortium Wormbase, Foltz NL, Schwarz EM, Sternberg PW

[West Coast Worm Meeting, 2000]

We briefly describe the current status and plans for WormBase, initially an extension of the existing ACeDB database with a new user interface. The WormBase consortium includes the team that developed ACeDB (Richard Durbin and colleagues at the Sanger Centre; Jean Thierry-Mieg and colleagues at Montpellier); Lincoln Stein and colleagues at Cold Spring Harbor, who developed the current web interface for WormBase; and John Spieth and colleagues at the Genome Sequencing Center at Washington University, who along with the Sanger Centre team, continue to annotate the genomic sequence. The Caltech group will curate new data including cell function in development, behavior and physiology, gene expression at a cellular level, and gene interactions. Data will be extracted from the literature, as well as by community submission. We look forward to providing the C. elegans and broader research community easy access to vast quantities of high quality data on C. elegans. Also, we welcome your suggestions and criticism at any time. WormBase can be accessed at www.wormbase.org.