Abstract
The messenger RNAs for the four subunits of larval serum proteins (LSPs) 1 and 2 were purified from third instar fat body total RNA by fractionating oligo(dT)-selected RNAs on the basis of size. Translations of RNA fractions in vitro showed that the LSP mRNAs were free of other fat body messenger activities, but they could not be completely resolved from each other. The molecular weights of the LSP mRNAs, estimated from their electrophoretic mobilities in 50% formamide/1.4% agarose gels, ranged from 1.0 X 10(6) to 1.35 X 10(6). These estimates are at least 20% larger than the size of RNA necessary to encode each LSP polypeptide.