The effects of testosterone on the mice pinealocytes: a quantitative study.

In order to determine the effects of testosterone upon the function of the pineal gland we quantitated, under the electron microscope, the number of dense-core vesicles, lysosomes, lipid droplets and the fractional volume of the pineal gland components in adult male mice. We studied six groups of mice submitted to different treatments as follows: treated with testosterone propionate (0.1 mg/10 g body weight for 15 consecutive days), castrated and the respective control mice. In mice treated with testosterone we observed a decrease in the number and fractional volume of dense-core vesicles and an increase in the fractional volume of lysosomes and lipid droplets. In castrated mice, without treatment, we observed a decrease in the number of lysosomes and an increase in the number and fractional volume of dense-core vesicles. These results show that testosterone is closely related to the secretory process of mice pinealocytes, playing an inhibitory role upon the functional activity of the pineal gland.

Obtaining mutants for protoplast fusion of gibberellin-forming Gibberella fujikuroi strains.

Auxotrophic, drug-resistant, nitrate-nonutilizing, and albino mutants have been isolated in Gibberella fujikuroi following UV mutagenesis. Protoplasts of complementing auxotrophic strains, mutants with resistance markers, or mutants blocked in different steps of the nitrate assimilatory pathway have been fused to form heterokaryons, diploids, or recombinant haploids. The properties of fusant strains, including gibberellic acid productivity, have been examined and compared to parent strains.