Date of Award


Degree Type


University or Center

Atlanta University (AU)

Degree Name




First Advisor

Dr. Lafayette Frederick


A study of the in vitro effects such chemicals as adenine, aureomycin, benzyl adenine, niacin and sodium barbital have on morphogenetic patterns in the water mold Allomyces macrogynus, has been conducted. Cultures of A.macrogynus have been grown on one-fourth strength Emerson's YpSs agar supplemented with each chemical. A nonsupplemented one-fourth strength YpSs agar served as the control. All cultures were grown under normal laboratory temperature and light conditions for a three-week period. Microscopic observations were made at the end of 7, 15 and 21 days to determine the extent of morphogenetic variations induced by the chemicals. At concentrations of 38/ml adenine and 38/ml benzyl adenine a higher percentage of male gametangia formed on gametothalli. Concentrations of 0.1 mg/ml benzyl adenine were found to induce a higher percentage of Z.S. to R.S. on sporothalli, whereas 98/ml of barbital sodium caused an increase in the number of gametangia forming on gamethothalli. Concentrations of 38/ml of benzyl adenine and 91/ml of barbital sodium were found to induce a higher percentage of R.S. on gametothalli. Concentrations of 91/ml of barbital sodium and 48/ml of aureomycin were found to induce "hyphal" protuberations from Z.S., whereas a concentration of 2S8/ml of barbital sodium induced "hyphal" protuberations from gametangia as well as sporangia. Concentrations of 18/ml and 48/ml of niacin were found to induce spore germination within Z.S. Cytochemically the presence of protein and nucleic acids was detected. It was concluded in light of these observations that the five organic chemicals used in this investigation exhibited distinct morphogenetic inductive principles which alter the regulatory mechanism in Allomyces macrogynus.

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