Cytotoxicity of ethyl methanesulfonate in mice spermatogonia.

Enumeration of different types of spermatogonia, following a single i.p. administration of different doses of ethyl methanesulfonate in mice, showed a survival of A1-A4 and in spermatogonia is markedly reduced due to cell killing while the remaining types of spermatogonia were affected marginally. The cell killing effect was dose-dependent, and replenishment of these cells was observed by the end of one cycle of the seminiferous epithelium comprising of 8.5 days.     

The influence of iodoacetate on the mechanism of nuclear glucose oxidation

Résumé Les expériences présentées montrent que dans les noyaux isolés du thymus de rat l'inhibition de glycéraldehyde-phosphate déhydrogénase stimule la production de¹⁴CO₂ de (6-¹⁴C) glucose. Un méchanisme capable d'expliquer cet effet est proposé et discuté.     

Influence of classical immunosuppressants on spleen colony formation in mice

Zusammenfassung Nachweis eines Hemmeffektes immunosupressiver Mittel (Cortison, Cyclophosphamide und Immuran) bei Mäusen nach UV-Bestrahlung auf die hämopoetische Regeneration (Milzkolonien und Knochenmarkzellen).     

Construction and use of human chromosome jumping libraries from NotI-digested DNA

A basic difficulty in the molecular analysis of genes identified by mutations in the mammalian genome is the need to cover genetic distances corresponding to several hundred kilobases or more by molecular techniques like chromosome walking. In chromosome jumping, this limitation is overcome by the deletion of all but the extreme ends of large DNA molecules before cloning. We describe here the construction and characterization of a NotI 'jumping library' from human DNA. To characterize this library, random clones were analysed by restriction mapping. Clones carrying unique end fragments were characterized further by hybridization to Southern blots of NotI-cleaved human DNA separated on pulsed field gradient (PFG) gels. As a first step in a directional walk, the library was screened with a clone containing a NotI site cleaved in genomic DNA ('NotI linking clone') localized to the distal third of the short arm of human chromosome 4 (A.-M.F. & T.P., unpublished data). Starting and end points of two identified clones were positioned within a restriction map covering 850 kilobases.