Isolation of messenger RNA coding for eggshell protein of the DNA-eliminating nematode Ascaris lumbricoides.

Poly(A)-containing RNA from polyploid uterine epithelial cells of Ascaris lumbricoides has been isolated by poly(U)-Sepharose chromatography. The bulk of poly(A)-containing RNA migrates as 18-S RNA in formamide/polyacrylamide gels. In a cell-free wheat germ system, this RNA directs the synthesis of a polypeptide with identical migration behavior in dodecylsulphate/urea/polyacrylamide gels as the polypeptide isolated from the proteinaceous eggshell. The two proteins reveal almost identical peptide patterns in fingerprint analysis. The authentic eggshell protein has been identified as a glycoprotein with a molecular weight of about 10000, as determined by dodecylsulphate/polyacrylamide gel electrophoresis. The apparent discrepancy between mRNA length and the required coding length for the protein is discussed.