In vitro mutagenicity of the soil nematicide 1,3-dichloropropene

Summary The cis- and trans-isomers of 1,3-dichloropropene have been tested in the Ames mutagenicity assay system on Salmonella typhimurium tester strain TA 1535. Both isomers have been found to be mutagenic even without microsomal activation.Acknowledgment. We wish to thank Mrs J. Ahamer for excellent technical help. We are also grateful to Deutsche Shell GmbH., Frankfurt, for their kind assistance in providing samples.     

In vitro mutagenicity testing of a potent,new, benzoyl urea insect growth regulator

Summary Bacterial mutagenicity assay to detect potential chronic toxicity of a potent, new, benzoyl urea insect growth regulator (CGA-112913 or IKI-7899, formerly UC-62644) was conducted using 5 histidine auxotrophs ofSalmonella typhimurium. Tests within the concentration range of 0.9–500 g (saturating)/plate of the compound with and without the 5–9 mammalian metabolic activation system showed no mutagenic effects clearing the way for long-term chronic toxicology studies.The authors thank Professor Bruce N. Ames for supplying the tester strains together with all the relevant information for conducting the bioassays and Ms. Norma Charlebois for her meticulous technical assistance.     

In vitro culture of larval amphibian erythroblasts.

A larval erythroblast culture method is described. By this method, it is possible to cultivate for several weeks a homogeneous population of cells (5-10(5) cells/ml medium on average after 4 or 5 days of culture), which are relatively synchronous with regard to their state of differentiation.     

In vitro induction of flowering inCucumis sativus L.

Zusammenfassung Erster Bericht über die Blütenbildung einer höheren Pflanze (Schösslinge vonCucumis sativus L.) im Reagenzglas und mit synthetischem Nährstoff, welche in der Natur männliche und weibliche Blüten hervorbringt.     

In vitro fertilization of the mongolian gerbil egg

Zusammenfassung Ova von mongolischen WüstenmäusenMeriones unguiculatus (Gerbillinae) wurden mit Spermatozoa aus der Epididymis in Follikelflüssigkeit von Kühen zusammengebracht. Es konnte gezeigt werden, dass die Spermatozoen während der Inkubation in diesem Medium die Fähigkeit erlangen, in die Ova einzudringen.     

In vitro lipid synthesis by lathyrogen-treated L-929 fibroblasts.

Aside from cholesterol, cholesterol esters and lyso-lecithin, the de novo lipid synthesic mechanisms which operate in cells grown in the presence of beta-amino-propionitrile are largely depressed and suggest that there may be in operation specific metabolic control mechanisms for regulation of cellular lipid composition.     

In vitro morphological characterization of the bursal reticuloepithelial (REp) cells of chicken.

The REp cells of the bursa follicle medulla of chicken were isolated in vitro. Culture of the REp cells was maintained over a period of 10 days and the cells were observed at 3 and 10 days by means of transmission electron microscopy (TEM) and immunofluorescence. The use of an anticytokeratin monoclonal antibody confirmed their epithelial nature. TEM observations showed the presence of desmosomes and tonofilaments, which are characteristic of epithelial cells. Furthermore, to some extent the cells regenerated in vitro the network they form in vivo. Though the growth rate becomes slower with time, the features of the REp cells do not significantly change.     

In vitro systems in the study of peroxisomal protein import

Our level of understanding of peroxisome biogenesis in comparison with other cellular organelles is rudimentary, yet the fragments of information available indicate that the targeting and import of peroxisomal proteins occur by fundamentally different mechanisms. Genetic studies have identified a number of genes required for peroxisome assembly, but in most cases the functions of the gene products remain unknown. In vitro protein translocation systems have played a prominent role in unravelling the biochemistry of protein translocation into other organelles. This review considers some of the requirements for establishing a bona fide peroxisomal import assay and discusses the findings which have emerged as a result of using such experimental systems.