Purification of a Family of Specific Messenger Ribonucleic Acids from Moth Follicular Cells

When moth follicular cells synthesize the characteristic, low-molecular-weight chorion (eggshell) proteins, they contain at least two groups of 8-9S RNAs which appear to be chorion mRNA. This class of RNA yields a characteristic radiolabeled profile on polyacrylamide slab gels. The same profile is obtained irrespective of whether lebeling is performed in vivo or in organ culture, and whether the RNAs are purified from whole cells or specifically released from polysomes. Polysomes contain putative chorion mRNA only when the cells actually synthesize chorion protein. The RNA size is correlated with the size of the chorion proteins: two month species differing in the size distribution of their chorion proteins show a corresponding difference in the size distribution of the RNAs.