Evidence of a store of informational RNA in encysted embryos of Artemia salina

RNA prepared from dormant cysts and developmental stages of the brine shrimp Artemia salina stimulated the incorporation of ¹⁴C-leucine into polypeptide by a cell-free Escherichia coli system. Preparations from cysts were about as active as those from hatching embryos or nauplii. When analysed by density gradient centrifugation the activity of cyst RNA showed a heterodisperse distribution, not quantitatively related to the absorbance profile. These results and evidence from similar experiments with crude ribosome preparations indicated that the contribution of 18S and 28S ribosomal RNA to the template-like activity was fairly limited. The experiments suggest that RNA with latent messenger activity is present in Artemia cysts during the resting stage.