Worm Breeder's Gazette 5(2): 30
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.
We have examined the titer of poly(A) RNA in squashes prepared from oocytes and variously staged embryos of the nematode Caenorhabditis istol (N2) by In situ hybridization with a [3H]-poly(U) probe. Control experiments demonstrated that this probe interacts specifically with poly(A) sequences and is capable of detecting poly(A) RNA. Using this method and saturating concentrations of the probe, it was shown that isolated oocytes and embryos up to the 125-cell state exhibited substantial levels of poly( A) RNA in their cytoplasms but almost no activity within their nuclei. Nuclear poly(A) RNA first appeared at the 90-cell stage and afterwards increased at a linear rate through the 550-cell stage. The titer of total embryonic poly(A) RNA also increased at a linear rate up to larval hatching. The results suggest that the major transcriptional effort for poly(A) RNA begins at the 90 to 125-cell stage of C. elegans embryogenesis and that the poly(A) RNA present exclusively in the cytoplasm prior to this time is of maternal origin.