Axoplasmic transport of RNA containing a polyadenylic acid segment.

The nature of the cytoplasmic RNA that appears to migrate along the optic path of the chick has been studied. A considerable proportion of retinally synthesized RNA contains a polyadenylic acid segment. A fraction of this presumptive messenger RNA moves distally to the optic tectum together with nonpolyadenylic acid-containing RNA. The poly(A)-containing and nonpoly(A)-containing RNA classes are transported in roughly the same proportions as their relative retinal cytoplasmic concentrations. The size of the poly(A) segments within the putative messenger RNA (mRNA) did not decrease with time. A proportion of nonmigrating mRNA in retina and optic tectum appeared to have considerable stability, as did transported mRNA.