Etemad-Moghadam B et al. (1994) Worm Breeder's Gazette "PAR-3 is a Novel Maternally Encoded Protein"

Etemad-Moghadam B, Kemphues KJ

[Worm Breeder's Gazette, 1994]

PAR-3 IS A NOVEL MATERNALLY ENCODED PROTEIN. Bijan Etemad-Moghadam and Kenneth Kemphues, Cornell University, Ithaca New York.

Guo S et al. (1994) Worm Breeder's Gazette "Identification of par-1 Gene by Injecting in vitro-transcribed anti-sense RNA"

Guo S, Kemphues KJ

[Worm Breeder's Gazette, 1994]

Identification of par-l gene by injecting in vitro- transcribed anti-sense RNA Su Guo, Kenneth Kemphues, Dept. of Genetics & Development, Cornell University, Ithaca, NY 14853

Caron C et al. (1994) Worm Breeder's Gazette "Analysis of zyg-1, a Gene Required During the First Embryonic Divisions and For Formation of a Functional Vulva"

Caron C, Kemphues KJ

[Worm Breeder's Gazette, 1994]

ANALYSIS OF zyg-1, A GENE REQUIRED DURING THE FIRST EMBRYONIC DIVISIONS AND FOR FORMATION OF A FUNCTIONAL VULVA. Cathy Caron and Kenneth Kemphues, Cornell University, Ithaca, New York.

Douglas Portman et al. (2005) International Worm Meeting "Specification of cell fates in the ray sublineage by the proneural gene lin-32 and the LIM-HD gene lim-7"

Douglas Portman, Kenneth Stewart, Kwi Yeon Lee

[International Worm Meeting, 2005]

Each of the 18 rays in the C. elegans male tail develops from a single ray neuroblast. In L3/L4 males, the ray neuroblast undergoes two rounds of asymmetric division to give rise to one programmed cell death and the three cells of each ray: the RnA and RnB sensory neurons and the Rnst structural cell. We are interested in the mechanism that governs the precise generation of these different but related cell types from a common precursor. We have previously shown that the bHLH transcription factor lin-32 is required for multiple steps of ray development. In the ray neuroblast, lin-32 specifies neural competence. Later, lin-32 is independently required for the proper differentiation of each branch of the ray sublineage. lin-32 expression is consistent with this model: activation of lin-32::GFP in the male seam is first detectable in the ray neuroblasts and continues until the final division of the ray sublineage. We have recently found that the expression of lin-32::GFP persists asymmetrically at the end of the sublineage, suggesting that the pattern of lin-32 expression may be important for patterning ray cell fates. However, other regulatory factors are likely to act downstream of or in parallel with lin-32 to create diversity in the ray lineage. The LIM-homeodomain gene lim-7 is an excellent candidate for such a factor. We identified this gene, the C. elegans Islet ortholog, in a microarray screen for new ray-expressed genes. lim-7::GFP is expressed transiently during the ray sublineage, in a more restricted pattern than lin-32, suggesting that it may act in a single ray cell type. In mosaic experiments using the lethal lim-7(tm674) deletion allele we have found that lim-7 is likely to be required for the expression of the tryptophan hydroxylase tph-1 in the RnB neurons. However, the expression of another RnB marker, pkd-2, is not affected, indicating that lim-7 does not control all aspects of RnB fate. To identify additional factors important for RnB specification, we are studying the cis-regulatory elements in a battery of seven genes, cwp-1 through -5, lov-1 and pkd-2, that are coexpressed in all RnB neurons but R6B. Though we have not yet identified common regulatory regions in by these genes, we have found that a short stretch of the first intron of pkd-2 is both necessary and sufficient for RnB expression. We are currently working to identify factors that act through this motif and to identify other RnB elements from genes in this battery. Together, we hope to assemble a more complete picture of the regulatory network that specifies neural subtype in the rays.

Van Voorhies WA (1999) Worm Breeder's Gazette "The effects of transferring on worm fertility"

Van Voorhies WA

[Worm Breeder's Gazette, 1999]

Worm fecundity is commonly assayed in many C. elegans studies. Any measurement of worm fecundity requires proper control of environmental factors that potentially affect worm fertility. In a recent article in the WBG (Twistering: A new approach to fecundity assays), Andrew Stewart mentioned that the developmental stage at which a worm is transferred significantly affected worm fecundity. Stewart reported that progeny counts recorded from worms transferred to plates as L3 worms were significantly less than progeny counts recorded from worms transferred to plates when either eggs or L2 worms. This implies that transferring older larval worms can damage the worm enough to reduce its fertility.

Antol, Weronika et al. (2022) MicroPubl Biol

Sychta, Karolina, Prokop, Zofia M., Antol, Weronika, Palka, Joanna K., Dudek, Katarzyna

[MicroPubl Biol, 2022]

Caenorhabditis elegans is a model species, increasingly used in experimental evolution studies to investigate such major topics as: maintenance of genetic variation, host-pathogen interaction and coevolution, mutations, life history, evolution of reproductive systems, sexual selection (Gray and Cutter, 2014; Teotnio, Estes, Phillips, and Baer, 2017). Its reproductive system in the wild, known as androdioecy, involves mostly self-fertilization of hermaphrodites and occasionally outcrossing with males, which are generally rare (Stewart and Phillips, 2002). This system can be experimentally changed to dioecy, i.e., obligatory outcrossing, through genetic manipulations (see Table I in Anderson, Morran, and Phillips, 2010; Gray and Cutter, 2014).

Tavernarakis NN et al. (1999) Trends in Biochemical Sciences "The SPFH domain: implicated in regulating targeted protein turnover in stomatins and other membrane-associated proteins."

Driscoll MA, Tavernarakis NN, Kyrpides NC

[Trends in Biochemical Sciences, 1999]

Stromatin, also known as band 7.2b protein, is one of the major integral membrane proteins of human erythrocytes. This protein is apparently absent in the red cell membranes of patients suffering form overhydrated hereditary stomatocytosis, a form of autosomal dominant hemolytic anemia. Although he protein is missing, no mutations have been found within the stomatin gene in patients with this condition. However, an aberrant splice mutation associated with multi-system pathology early in life suggests that the protein is crucial for development (A. Argent, J. Delaunay and G. Stewart, pers. commun.). the genome of the nematode Caenorhabditis elegans encodes nine stomatin-related genes, three of which have been genetically characterized. MEC-2 is a protein expressed predominantly in six touch-receptor neurons and plays an essential role in mechanotransduction, whereas UNC-24 is required for normal locomotion. UNC-1 also affects locomotion and is required for normal responsiveness to volatile anesthetics.

Stewart HI et al. (1994) Worm Breeder's Gazette "Correlating the Physical and Genetic Maps on Chromosome III (Left) - A First Step."

Baillie DL, Stewart HI, Collins D

[Worm Breeder's Gazette, 1994]

Correlatina the Phvsical and Genetic MaDs on Chromosome III (Left) - A First step Diana Collins, Helen 1. Stewart and David L. Baillie, Institute of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC As reported in the June 1994 issue of the WBG, the sequencing consortium is rapidly completing the sequence of chromosome III. Concurrently, our lab has been generating a large number of new mutations in the region covered by the free duplication sDp3 (approximately 75% of chromosome III, leftl (1). These mutations include EMS induced point mutations in essential genes and small, UV/Gamma induced deletions (see H. Stewart et al, this issue). In collaboration with the C. elegans genome sequencing consortium, specifically the St. Louis lab, our lab has begun the task of correlating the genetic and physical maps on the left arm of chromosome III. As a first step toward this goal, I have been micro injecting cosmid DNA received from St. Louis (my thanks to P. Latreille) into N2 hermaphrodites to create stable transgenic strains carrying specific sequenced cosmids. It is our intention to use these transgenic strains to cross these cosmids into various mutant strains and observe if the DNA is able to rescue the mutant phenotype. In this manner we will be able to place a large number of genetic markers on the physical map. Germline transformation is performed as per Mello et al. (1991), with cosmid DNA normally being injected at an approximate concentration of 20 ng/ul Prior to injection, cosmid DNA is mixed with the plasmid pCes 1943 to form an injection mixture having a total DNA concentration of approximately 100 ng/ul . pCes 1943 is derived from the plasmid pRF4 (2). It contains the dominant rol-6(sulO06) allele (3), and has been modified to contain a kanR cassette. Transformant strains which stabily give rol-6 progeny are PCR tested to confirm the presence of cosmid DNA. It has been my observation that approximately one stable rol-6 transformant in four does not contain cosmid DNA. So far I have produced transgenic strains from 22 cosmids: C06E8, C06G4, C14B9 C18H2, C29E4, C30C5, D2007, F08F8, FllH8, F31E3, F37C12, F44B9, K06H7, K07D8, R151, R13A5, T04A6, T20B12, T20H4, T21 D11, ZK652, and ZK688. Although there are a few cosmids left of mec-14 which I have not been able to successfully inject (due to problems with DNA availability or possible dosage effects), these transgenic strains represent a reasonably continuous stretch of DNA approximately 654 000 bp long. Preliminary crosses between lethal bearing strains and cosmid-containing transformants have yet to reveal a cosmid rescue. However, as our newly generated mutations are further mapped with respect to previously generated physical markers, the task of choosing cosmids which are likely to rescue particular mutants will become easier. In the meantime we are making these transformant strains available to the C. elegans community. If you would like us to send you any of these strains please contact me at: dcollins@darwin.mbb.sfu.ca This research is being funded by a grant from the Canadian Genome and Associated Technologies (CGAT). 1) Collin, D H Stewart and D. L. Baillie 119941 WBG Vol 13 No 2 66 2) Mollo, C, J Kramer, D Stinchcomb, and V Ambros 119911 EMB0 J Vol 10 3959-3970 3) Kramer J M, E Fronch, E Park, and J Johnson 119901 Mol Coll 8iol Vol 10 2081-2089

Francesca P et al. (1998) European Worm Meeting "HP1 homologues in C. elegans"

Francesca P, Fritz M

[European Worm Meeting, 1998]

The chromosomes of almost all higher eukaryotes contain regions, termed heterochromatin, that differ from the bulk of chromatin (euchromatin) in that they remain constitutively condensed throughout the cell-cycle. The DNA of heterochromatin consists almost entirely of repetitive sequences and encodes relatively few genes. Heterochromatin may play essential roles in mitosis, meiosis, gene expression and nuclear organization. The most well studied heterochromatin binding protein is the essential Drosophila heterochromatin binding protein 1 (HP1). HP1 is found in the heterochromatin of the chromocenter and in a limited number of other loci, including telomeres. HP1-like proteins have subsequently been identified in a number of species and share two regions with a high degree of amino acid conservation: an amino-terminal chromo domain (chromosome organization modifier), and a carboxy-terminal chromo shadow domain (Aasland and Stewart, 1995.) Both chromo and chromo shadow domains are able to target proteins to their site of action on chromatin. C. elegans mitotic chromosomes are holocentric and by definition do not have a localized centromeric region, nor do they have large tracts of heterochromatin. The C. elegans sequencing project, however, has identified two protein containing both chromo and chromo shadow domains, which we are now studying in our laboratory. hpl-1 maps on the right arm of the X chromosome, to the right of the unc-9 locus. Analysis of the genetic map of this region has not revealed the presence of any previously isolated candidate mutations for the hpl-1 locus. The other gene being studied hpl-2, maps to the middle of chromosome III. We are now testing whether the dominant maternal effect mutation mel-23, which maps to this region, corresponds to hpl-2 by microinjection rescue. We are also trying to isolate mutations in these two genes by a reverse genetic approach using Roberts Barstead method for isolating deletions in PCR screens of mutagenized populations. The study of HP1 homologues in C. elegans should shed light on the functions of this conserved family of proteins in an organism with vastly different chromosome organization and behaviour. Aasland and Stewart, N.A.R. 23:3168-3173

Hartman PS et al. (1995) Photochem Photobiol "Genetic and molecular analyses of UV radiation-induced mutations in the fem-3 gene of Caenorhabditis elegans."

Dwarakanath VN, DeWilde D, Hartman PS

[Photochem Photobiol, 1995]

The utility of a new target gene (fem-3) is described for investigating the molecular nature of mutagenesis in the nematode Caenorhabditis elegans. As a principal attribute, this system allows for the selection, maintenance and molecular analysis of any type of mutation that disrupts the gene, including deletions. In this study, 86 mutant strains were isolated, of which 79 proved to have mutations in fem-3. Twenty of these originally tested as homozygous inviable. Homozygous inviability was expected, as Stewart and coworkers had previously observed that, unlike in other organisms, most UV radiation-induced mutations in C. elegans are chromosomal rearrangements of deficiencies (Mutat. Res. 249, 37-54, 1991). However, additional data, including Southern blot analyses on 48 of the strains, indicated that most of the UV radiation-induced fem-3 mutations were not deficiencies, as originally inferred from their homozygous inviability. Instead, the lethals were most likely "coincident mutations" in linked, essential genes that were concomitantly induced. As such, they were lost owing to genetic recombination during stock maintenance. As in mammalian cells, yeast and bacteria, the frequency of coincident mutations was much higher than would be predicted by chance.