Gene expression and development : the third of five volumes constituting the proceedings of the 4th International Congress on Isozymes, held in Austin, Texas, June 14-19, 1982 / editors, Mario C. Rattazzi, John G. Scandalios, Gregory S. Whitt.

International Congress on Isozymes

Date:: [cl983]

Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: Gene expression and development : the third of five volumes constituting the proceedings of the 4th International Congress on Isozymes, held in Austin, Texas, June 14-19, 1982 / editors, Mario C. Rattazzi, John G. Scandalios, Gregory S. Whitt. Source: Wellcome Collection.

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$26 / Scandalìos 1 \ 1 1 (R6-67X R6-43)xR6-67 R6-43 R6-67 ▼ ▼ e о e « e «««d ••e« • OQ«* о • e QoaaaQQQammmQQ. оололтошллтшлол 1 1 1 1 1 1— (R6-67X R6-43)(g) R6-4 3 R&67 ▼ ▼ О о Q О •oo eoo eoe e oeo e eoe «e •oe*ee eeeee«e e •oooeeoo • оео#еоое« oo eoo««eoéeo ее •oe«eoeo*e*« e* e« 00 •oeee*eee«e«e oee oeo*« от eooeoooee.oe»ei«i#e». е«еее офм e 0 50 100 150 200 250 300 350 ADH ACTIVITY Fig. 20. Data showing the independent segregation between the level of ADH activity and the variants of the ADH structural genes in crosses between R6-67 and R6-43. ADH activity and electrophoretic variants of each scutellum were determined by assay and by starch gel electrophoresis. Each circle represents one scutellum and was plotted along the horizontal axis according to its level of ADH activity. The ADH genotype of each scutellum was indicated by: • = FF, Ö = FS, О = SS. The mean of ADH activities of the parents is indicated by arrows. (From Lai and Scandalios [1980], with permission.) with high catalase activity levels, like R6-67, but with normal (low) ADH activity levels, similar to W64A, and vice versa. Turnover studies combining density labeling (deuterium oxide, D2O) with cesium chloride isopycnic centrifugation were undertaken to determine whether or not the Adrl locus controls ADH-2 synthesis and/or degradation. Using this technique, Lai and Scandalios [1980] found no evidence of significant ADH-2 synthesis in the scutellum of either W64A or R6-67 during early seedling development. These results confirm those obtained in earlier studies with W64A [Lai and Scandalios, 1977] and suggest that Adrl operates by influencing enzyme degradation. ''r$