Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published March 1984 | public
Journal Article

Steroid regulation of RNAs transcribed from the Drosophila 68C polytene chromosome puff

Abstract

The 68C region of the Drosophila melanogaster salivary gland polytene chromosomes harbors the structural genes for the three salivary gland glue proteins sgs-3, sgs-7, and sgs-8. This region is puffed during the third larval instar, the stage when glue proteins are being produced in the salivary glands. The puff regresses near the end of the third instar as a result of an increased titer of the steroid hormone ecdysterone in the larval hemolymph. The experiments reported here were designed to determine whether the ecdysterone effect on puffing at 68C is correlated with hormone effects on expression of the three puff RNAs. In the first series of experiments, it is shown that there is a more rapid disappearance of 68C RNA transcripts from salivary glands cultured in the presence of ecdysterone than from glands cultured in its absence. The second set of experiments, in which 68C transcripts were pulse-labeled in salivary glands cultured in the presence or absence of hormone, demonstrates that one effect of ecdysterone is to cause a sharp reduction in the rate at which newly synthesized 68C transcripts accumulate. The final experiments follow the time required for ecdysterone to produce this effect, and show that it occurs in salivary glands exposed to the hormone for as little as 15 min. In all of the experiments, the RNA products of the Sgs-3, Sgs-7, and Sgs-8 genes acted coordinately.

Additional Information

© 1984 Published by Elsevier Inc. Received 25 August 1983, Accepted 13 October 1983. We thank J. Kendall for technical assistance, and M. Crosby, K. Fryxell, M. Garflnkel, L. Leutwiler, and R. Pruitt for critical reading of the manuscript. This work was supported by Grant GM28075 awarded to E.M.M. by the Institute of General Medical Sciences, National Institutes of Health. T.E.C. was supported by a National Research Service Award (1 T32 GM07616), also from the Institute of General Medical Sciences, National Institutes of Health. This work was supported by Grant GM28075 awarded to E.M.M. by the Institute of General Medical Sciences, National Institutes of Health. T.E.C. was supported by a National Research Service Award (1 T32 GM07616), also from the Institute of General Medical Sciences, National Institutes of Health.

Additional details

Created:
August 19, 2023
Modified:
October 23, 2023