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.

The Actin Gene is Transcribed in 4-8 Cell Ascaris Embryos

Peter J. Cleavinger, Jim W. McDowell and Karen J. Bennett

Figure 1

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]

Figure 1