CSM News Electronic Edition Volume 1, number 6 June 19, 1993 Please submit abstracts of your papers as soon as they have been accepted for publication by sending them to CSM-News@worms.cmsbio.nwu.edu. Following the usual abstracts is a list of cDNA and genomic libraries which has been compiled by David Knecht. This file will also be available for anonymous ftp in the Dicty archive on "worms.cmsbio.nwu.edu". ========================================================================== Abstracts of Recently Accepted Papers. SYSTEMATIC ANALYSIS OF ANTISENSE RNA INHIBITION OF MYOSIN II HEAVY CHAIN GENE EXPRESSION IN DICTYOSTELIUM DISCOIDEUM Carol A. Scherczinger and David A. Knecht* Dept. of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269 Antisense Research, in press. The powerful potential of antisense nucleotide inhibition of gene expression is presently being exploited in many biological systems, Although use of the technique is widespread, little is known about the variables which contribute to experimental success. We sought to define those variables which affect inhibition of myosin II heavy chain (MIIHC) gene expression by stable nuclear-derived antisense RNAs in Dictyostelium discoideum. Different fragments of the MIIHC gene cloned in antisense orientation into several transformation vectors were introduced into cells, and the accumulation of MIIHC protein and mRNA was examined. Inhibition of expression ranged from slight to virtually complete, and depended only on the specific gene fragment used to generate the antisense RNA. Fragments of the 3' end of the gene were the most effective and resulted in almost complete inhibition, while 5' fragments gave very little reduction. The severity of the morphological phenotypes associated with MIIHC depletion reflected the different levels of MIIHC in the transformants. Important implications for the design of antisense vectors suggested by these results are discussed. ======================================================================= Co-Supression of Dictyostelium discoideum Myosin II Heavy Chain Gene Expression by a Sense Orientation Transcript Carol A. Scherczinger and David A. Knecht* Dept. of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269 Development, in press We have previously demonstrated effective inhibition of Dictyostelium discoideum myosin heavy chain (MIIHC) gene expression after introduction of an antisense gene into cells on a transformation vector. We now report that transcription of a sense orientation MIIHC gene has a similar, though not as dramatic effect on expression from the endogenous gene. Cells transformed with a sense fragment of the MIIHC gene are defective in cytokinesis and become giant and multinucleated when growing on a surface. This morphological phenotype is correlated with decreased expression of the endogenous MIIHC gene. Sense transformants accumulate less MIIHC protein and mRNA than control transformed cells, concomitant with accumulation of a vector-derived sense transcript. Expression of the introduced sequences seems to be required for the sense effect. The possible causes of this surprising phenomenon are discussed. ======================================================================= Dictyostelium Gene Libraries The following list of gene or cDNA libraries which have been produced are available from the person indicated. This list was originally generated at the Vancouver Dictyostelium meeting in 1991 and was updated at the 1993 Dictyostelium meeting in the Netherlands. If you have other libraries which you would be willing to share, or if you have corrections to this list please send a description to CSM-News@worms.cmsbio.nwu.edu. Library Type Vector Person to Contact _______________________________________________________________________ cDNA 4 hr lambda ZAP R. Firtel cDNA 12-16 hr lambda ZAP Tel. (619) 534-2788 Genomic pATANB43 Fax (619) 534-7073 3h shaking cells (lmm cAMP at TO) lambda gt11 G. Podgorski Tel. (801) 750-3712 Fax (801) 750-1575 ~5 hr. cDNA, pulsed with cAMP lambda gt11 A. Kimmel Tel. (301) 496-6870 Fax (301) 496-5239 (now available thru Clonetech) cDNA late vegetative lambda gt11 A. Kaplan Tel. (314) 577-8440 Fax (314) 773-3403 Genomic Random lambdaZAP H. Ennis random sheared ph: 201-235-3427 cDNA 1h spore fax: germination lambda gt10 cDNA 3h spore germination lambda gt10 cDNA vegetative lgt10 lambda gt10 cDNA vegetative lambda gt11 C. Rutherford cDNA mid slug lambda gt11 Tel. (703) 231-5349 (small inserts,