Experimental and genetic analysis of root development inArabidopsis thaliana

The cellular organisation of theArabidopsis thaliana root is remarkably regular. A fate map of the primary root and root meristem that predicts the developmental destinies of cells within the embryonic root primordium has been constructed. Nevertheless, laser ablation experiments demonstrate that root meristem cells develop according to position and not according to lineage. Mutational analysis has identified genes required for cell specification in the radial as well as in the apical-basal dimension. The corresponding gene functions appear to be necessary during embryogenesis for the formation of a correctly patterned primary root. H Lambers Section editor     

Purification of Tumor Associated Antigens from a Methylcholanthrene Induced Murine Sarcoma as Monitored by Humoral Cytotoxicity

Tumor associated antigens have been purified from a methylcholanthrene sarcoma of syngeneic mice by detergent extraction, column chromatography and isoelectric focusing. The antigen was measured by a sensitive humoral cytotoxicity assay based on inhibition of uptake of ³H thymidine by tumor cells growing in culture in the presence of antibody and complement.     

Cellular autofluorescence--is it due to flavins?

For many cell types, cellular autofluorescence in the 500-600 nm spectral region can result in a significant background signal for measurements of weakly fluorescent probes. Measurements of fluorescence intensity and spectra of a variety of cell types and assays of neuronal homogenates are presented to demonstrate that this autofluorescence is most likely due to endogenous flavoproteins.