Worm Breeder's Gazette 10(3): 77
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
As early as the 4-8 cell stage in Ascaris embryogenesis, we can detect zygotic transcription of actin message. By run-on transcription assays with isolated nuclei from synchronous populations of Ascaris embryos (as reported in WBG 10-1:76 and 10-2:67), we detect actin transcription at all the early stages, as seen in the figure below. In these same stages we have not detected transcription of the major sperm protein, -tubulin, myosin or the collagen genes, using Ascaris bulin DNAs and the C. elegans both of which cross-hybridize with Ascaris sequences. The SP6 vector alone was used as a negative control. Ascaris ribosomal and mitochondrial DNAs were positive controls. The actin signal is eliminated when the reaction is carried out in the presence of 1 g/ml alpha-amanitin as expected for a RNA polymerase II transcribed message, while the ribosomal and mitochondrial signals are unchanged (not shown). The C. elegans nuclei were a kind gift of B. Dalley. Detection of a specific message with [32P] labeled RNA. Dots of linearized, denatured DNA of 0.1 and 1.0 g were hybridized with RNAs from 4-8, 16, 30, and 60 cell stages, as well as RNAs from a mixed population of C. elegans embryos. From 3-20x10+E6 cpm of label were added. The hybridizations were for 72 hr and the films were exposed for 7-8 days for the 4-8 cell, the 30-cell, and the C. elegans preparations; for 3 days for the 16 cell RNA, and overnight for the 60 cell RNA. Only 0.1 g dots were used with the 30 cell and C. elegans transcripts for the RNA polymerase II sensitive DNAs. [See Figure 1]