Abstract
The ges-1 gene of the nematode Caenorhabditis elegans codes for a nonspecific carboxylesterase that is expressed only in the intestinal lineage. This esterase has turned out to be a convenient biochemical marker for lineage-specific differentiation. In the present paper, we describe the production of several C. elegans strains that lack detectable activity of the ges-1 esterase. To isolate these ges-1 null strains, we first produced a strain of hermaphrodites in which the wild-type copy of the ges-1 gene was stably balanced over a previously isolated isoelectric focusing allele, ges-1(ca6); this parental strain was then mutagenized with EMS and isoelectric focusing gels were used to identify progeny populations that lacked either ges-1(+) or ges-1(ca6) esterase activity. This method is a straightforward and general approach to obtaining null mutations in any gene that has a biochemical or immunological assay. The ges-1 gene is not essential to worm survival, development or reproduction. Furthermore, lack of the ges-1 product has no obvious effect on the ability of worms (containing either normal or greatly reduced levels of acetylcholinesterases) to survive exposure to esterase inhibitors. The ges-1 gene product provides roughly half of the total esterase activity measured in crude extracts of L1 larvae or mixed worm populations. However, histochemical staining of individual ges-1(0) embryos shows that the ges-1 esterase is the first and essentially the only esterase to be produced during embryonic development, from the midproliferation phase up to at least the twofold stage of morphogenesis. These ges-1(0) strains now allow us to investigate the developmental control of the ges-1 gene by DNA-mediated transformation, in which the ges-1 gene acts as its own reporter.
Full Text
The Full Text of this article is available as a PDF (5.2 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Brown T. M., Brogdon W. G. Improved detection of insecticide resistance through conventional and molecular techniques. Annu Rev Entomol. 1987;32:145–162. doi: 10.1146/annurev.en.32.010187.001045. [DOI] [PubMed] [Google Scholar]
- Culotti J. G., Von Ehrenstein G., Culotti M. R., Russell R. L. A second class of acetylcholinesterase-deficient mutants of the nematode Caenorhabditis elegans. Genetics. 1981 Feb;97(2):281–305. doi: 10.1093/genetics/97.2.281. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Edgar L. G., McGhee J. D. DNA synthesis and the control of embryonic gene expression in C. elegans. Cell. 1988 May 20;53(4):589–599. doi: 10.1016/0092-8674(88)90575-2. [DOI] [PubMed] [Google Scholar]
- Edgar L. G., McGhee J. D. Embryonic expression of a gut-specific esterase in Caenorhabditis elegans. Dev Biol. 1986 Mar;114(1):109–118. doi: 10.1016/0012-1606(86)90387-8. [DOI] [PubMed] [Google Scholar]
- Herman R. K. Crossover suppressors and balanced recessive lethals in Caenorhabditis elegans. Genetics. 1978 Jan;88(1):49–65. doi: 10.1093/genetics/88.1.49. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Leslie J. F., Cain G. D., Meffe G. K., Vrijenhoek R. C. Enzyme polymorphism in Ascaris suum (Nematoda). J Parasitol. 1982 Aug;68(4):576–587. [PubMed] [Google Scholar]
- McGhee J. D., Cottrell D. A. The major gut esterase locus in the nematode Caenorhabditis elegans. Mol Gen Genet. 1986 Jan;202(1):30–34. doi: 10.1007/BF00330512. [DOI] [PubMed] [Google Scholar]
- Read S. M., Northcote D. H. Minimization of variation in the response to different proteins of the Coomassie blue G dye-binding assay for protein. Anal Biochem. 1981 Sep 1;116(1):53–64. doi: 10.1016/0003-2697(81)90321-3. [DOI] [PubMed] [Google Scholar]
- Rosenbluth R. E., Baillie D. L. The genetic analysis of a reciprocal translocation, eT1(III; V), in Caenorhabditis elegans. Genetics. 1981 Nov-Dec;99(3-4):415–428. doi: 10.1093/genetics/99.3-4.415. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rosenbluth R. E., Cuddeford C., Baillie D. L. Mutagenesis in Caenorhabditis elegans. II. A spectrum of mutational events induced with 1500 r of gamma-radiation. Genetics. 1985 Mar;109(3):493–511. doi: 10.1093/genetics/109.3.493. [DOI] [PMC free article] [PubMed] [Google Scholar]