Morton DG et al. (1990) Worm Breeder's Gazette "Maternal Mutations that Alter the E Lineage"

Kemphues KJ, Morton DG

[Worm Breeder's Gazette, 1990]

In our screens for maternal effect lethal mutants that fail to differentiate intestine, we identified 4 mutants in which the embryos arrest as masses of many differentiated cells, have normal early cleavage patterns, localize P granules normally, but fail to produce gut granules. (WBG 10(2) p. 56, 1988). These mutants may identify genes that are important for specification of the intestinal cells in C. elegans development. We have found that all four of these mutants exhibit a specific alteration in the E cell lineage: Ea and Ep divide prematurely and fail to move to the interior of the embryo to begin the process of gastrulation. The daughter cells remain at the surface of the embryo. The division of Ea and Ep in the mutants occurs 6-12 minutes earlier than in wild type, and immediately follows the division of MSa and MSp. This E lineage-defective phenotype is the earliest defect that we have identified for the mutants. This early phenotype suggests that the absence of differentiated intestinal cells in late stage embryos may result from a defect in the determination of the E lineage. We hope to ascertain the fates of the E daughter cells in the mutants and to learn whether other cell lineages are affected. The mutant embryos produce body wall myosin, indicating that differentiation of body wall muscle cells, at least, is not blocked by these mutations. The four mutations, it92 V, it93 I. it103 II and it125 II, while giving very similar phenotypes, each identify a different gene. This was somewhat surprising to us, since the mutations were identified from screens of over 23,000 haploid genomes, in which we were able to identify 7 new par-4 alleles and 6 par-1 alleles. The rare mutations that give an E lineage-defective phenotype may be unusual alleles of their respective genes, or may identify genes that are unusually small or rarely mutated. We are presently mapping the mutations and doing complementation tests with lethals in these regions to distinguish between these possibilities. The fact that we obtained only one mutation in each locus also suggests that we have not saturated the genome for mutations of this kind. In fact, Jocelyn Shaw and coworkers have followed our screening procedure and identified additional mutants with different map locations that give similar E lineage alterations (C. elegans Meeting Abstracts, p. 231,1989). One mutation is allelic with it92 (J. Shaw pers. communication). We are collaborating with the Shaw lab on further genetic and phenotypic analyses of E lineage-defective mutations. We hope that our studies of these mutations will provide insights into how the embryonic intestinal cell lineage pattern and determination of cell type is controlled.

Hodgkin JA et al. (1993) Worm Breeder's Gazette "Caenorhabditis Genetic Map and Nomenclature E-Mailing List"

Hodgkin JA, O'Callaghan M

[Worm Breeder's Gazette, 1993]

Most of the points covered in the accompanying 'Nomenclature Guidelines -- New Recommendations' contribution were circulated by e-mail before the June 1993 meeting, to principal investigators with e-mail addresses, for their comments and reactions. This procedure appeared to be efficient and helpful. We wish to expand our e-mailing list for nomenclature issues, and for recommended methods of data submission. For this reason, we sent a message in August 1993 inviting other potentially interested parties to join this list, using the e-mail addresses from the 1993 WBG Subscriber Directory. We repeat this message below, for the benefit of readers who have e-mail access but did not receive our invitation. If you are interested, send us an e-mail message asking to be added to the list. From cgc@mrc-lmb.cam.ac.uk Dear WBG subscriber At present, CGC e-mail messages about methods of data submission, nomenclatorial issues and so on, are sent to all investigators with assigned lab codes (strain and allele designations) and known e-mail addresses. We would like to extend this mailing list to other interested parties who can be reached by e-mail. If you wish to be included on this expanded e-mailing list, please reply to this message, and you will be added to the list. Investigators already on the list need take no action. Regardless of whether you join the list, you will still be able to take note of any significant new recommendations, because these will be duly announced in issues of the Worm Yours sincerely, Jonathan Hodgkin Mary O'Callaghan

Shaw JE et al. (1991) Worm Breeder's Gazette "MATERNAL EFFECT LETHAL MUTANTS LACKING GUT GRANULES."

Stiernagle TL, Sigurdson DC, Shaw JE

[Worm Breeder's Gazette, 1991]

Using the screen for maternal effect lethal mutants developed by Ken Kemphues and Jim Priess, we have been looking for mutants whose inviable progeny fail to make gut granules in a manner similar to that described by Diane Morton et al (WBG Vol. 10 #2). With this screen we hope to identify mutations in genes that are required for proper specification of the E lineage. The mutants that we retain from the screen have inviable progeny that divide to >200 cells (approx), are not multinucleate, and do not make gut granules as detected under polarized light. The mutants that we recover from this screen have fallen into three classes: par mutants (par-1, par-3, by Kemphues et al.); those that we are unofficially calling gut mutants (gut defective); and those that we are unofficially calling ggl (gut granuleless). We have concentrated on characterizing mutants of the gut and, to some extent, the ggl classes. From screens of approximately 32,000 EMS-treated haploid genomes and 16,000 gamma-irradiated haploid genomes we have recovered 13 gut mutants and 4 ggl mutants. We have also obtained 3 mutants of the gut class from Diane Morton with whom we are collaborating to characterize this class of mutant. The combined set of gut mutants contains mutations in at least 10 different complementation groups with only two genes represented by more than one allele. The ggl class of mutant is represented by four alleles in a single complementation group. The classification of mutants is based on observations of both early embryogenesis and the terminal phenotype in progeny of mutant hermaphrodites. Embryos of gut mutants divide in a normal asymmetric and asynchronous pattern during very early cell divisions, thus distinguishing them from par mutants. P granules are also segregated normally. Embryonic cell divisions in these embryos appear to be fairly normal in timing and pattern until the beginning of gastrulation. At that time in wild-type development the two E cells' division rate slows and the E cells begin to move into the center of the embryo. In gut mutants the E cells' division rate does not slow and the E. coli's do not gastrulate. These embryos arrest development embryonically as a ball of cells (approx. 400-600 nuclei) with no apparent morphogenesis. As well as lacking gut granules, the embryos fail to produce two antigens that are normally found in differentiated gut cells (assayed by antibodies J126 and SP37 from S. Strome). They do undergo some differentiation; we observe cell-death nuclei, neuronal nuclei, and large amounts of MyoB (anti-myoB from D. Miller). In embryos of ggl mutants early divisions including E cell division and gastrulation appear to be normal. Although these embryos fail to produce gut granules they do make significant amounts of the gut- specific products recognized by SP37 and J126. Since we believe that at least some of the gut genes are most specifically involved in proper specification of the E lineage we are concentrating on further characterizing these genes genetically and molecularly.

Prasad BC et al. (1997) Worm Breeder's Gazette "unc-3 gene encodes the C elegans homologue of the mammalian transcription factor O/E-1"

Prasad BC, Reed RR

[Worm Breeder's Gazette, 1997]

The mammalian olfactory system utilizes specialized signal transduction components to detect odors. These olfactory genes contain consensus sites for a family of trans-acting factors which includes Olf-1/EBF (O/E-1). The O/E-1 protein is expressed at high level in adult olfactory neurons and transiently during embryogenesis in a variety of other neuronal tissues. The laboratory is actively trying to understand the role of this family of transcription factors in mouse neurodevelopment. We have identified a C elegans homologue of the mammalian O/E-1 protein. We believe that the C elegans homologue of O/E-1 (Ce O/E-1) is encoded by the unc-3 gene, mutations in which are reported to cause all classes of motor neurons in the ventral cord to have disorganized processes and make neuro-muscular junctions at ectopic sites. We have identified point mutations in the Ce O/E-1 coding region for three unc-3 alleles. We have used GFP fusions to the promoter of the Ce O/E-1 protein and specific antibodies to the protein to study the pattern of expression. The Ce O/E-1 protein is expressed as early as bean stage and continues to be expressed in the neurons of the ventral cord and the ASI chemosensory neurons throughout development. These observations are consistent with a similar role for O/E proteins in both mice and nematodes, i.e., these transcription factors play an essential role in the determination of the terminal phenotype of neurons.

Mains PE (1994) Worm Breeder's Gazette "Interactions Between mei-1 and the unc-116 Kinesin"

Mains PE

[Worm Breeder's Gazette, 1994]

Interactions Between mei-l and the unc-116 Kinesin Paul E. Mains, Dept. of Medical Biochemistry, University of Calgary, Calgary, Alberta, Canada

Kuwabara PE (1994) Worm Breeder's Gazette "Evidence For Interactions Between the Sex Determination and Dosage Compensation Pathways in the Germline"

Kuwabara PE

[Worm Breeder's Gazette, 1994]

Evidence for Interactions Between the Sex Determillation and Dosage Compensation Pathways in the Germline Patricia E. Kuwabara MRC-LMB Hills Road Cambridge CB2 2QH England

Wissmann AK et al. (1994) Worm Breeder's Gazette "Characterization of the let-502 Gene"

Mains PE, Wissmann AK, McGhee JD

[Worm Breeder's Gazette, 1994]

Characterization of the let-502 gene Andreas Wissmann, James D. McGhee and Paul E. Mains, Dept. of Medical Biochemistry, University of Calgary, Calgary, Alberta, Canada T2N 4N1

Musset-Bilal F et al. (1994) Worm Breeder's Gazette "Characterization of the C. elegans Basement Membrane-Associated Protein SPARC"

Musset-Bilal F, Schwarzbauer JE, Ryan CS

[Worm Breeder's Gazette, 1994]

Characterization of the C. elegans Basement Membrane- Associated Frederique Musset-Bilal, Carol S. Ryan, and Jean E. Schwarzbauer Department of Molecular Biology, Princeton University, Princeton NJ 08544

Goldstein B (1992) Worm Breeder's Gazette "Identification of the Cues Used to Generate Blastomere Diversity:The Role of the P2-EMS Interaction in Positioning Gut Fate Into E"

Goldstein B

[Worm Breeder's Gazette, 1992]

The gut of C. elegans derives from all the progeny of the E cell, a cell of the eight cell stage (Sulston et al. 1983 Dev. Biol. 100:64.) In order for E to form gut, EMS must contact P2 during the four cell stage (Goldstein 1992 Nature 357:255; [See Figure].) P2 'sposition on the "E" side of EMS raises the possibility that the P2 -EMSinteraction is the cue that makes E different from MS. Alternatively, the E and MS sides may be different from each other before the P2 -EMSinteraction, such that only the E side can form gut in response to the interaction. In order to determine which is the case, I tried to move P2 to the MS side of EMS, to see if MS then forms gut. This is a particularly frustrating manipulation. A more feasible way to address the question turned out to be isolating P2 and EMS, and then placing the two cells back in contact in a random orientation. If any side of EMS can form gut in response to the interaction, then gut should always form from the daughter of EMS that contacts P2 .If however only the E side can form gut, then in some cases either gut will form from the daughter away from P2 or gut will not differentiate. Fortunately, P2 and EMS stick immediately upon contact and they do not rotate around each other when placed back together, precluding the possibility that P2 moves back to its original position. Which daughter of EMS formed gut was then determined by one of two methods: In five cases cell division times were watched to see which daughter took on E-like cell division timings, and in another five cases the daughters of EMS were separated from each other and cultured individually to see which produced gut granules. Gut differentiated from the side of EMS on which P2 was placed in all ten cases. This result indicates that any side of EMS can form gut in response to the induction, and hence that the interaction with P2 is what makes E different from MS. Current work is aimed at identifying cellular mechanisms by which the induction makes E different than MS, and determining whether cell interactions are required at other stages for gut fate to be segregated into E.

Hubbard EJA et al. (1994) Worm Breeder's Gazette "Genetic Analysis of sel-10."

Hubbard EJA, Greenwald IS

[Worm Breeder's Gazette, 1994]

Genetic analysis of sel-10 E. Jane Albert Hubbard and Iva Greenwald Department of Biochemistry and Molecular Biophysics and Howard Hughes Medical Institute, Columbia University, New York, New York, 10032