Detection and partial characterization of egg polypeptides from Heteroderaglycines

The presence of two major egg polypeptides was demonstrated in the plant-pa rasitic nematode Heterodera glycines. The polypeptides were present in equa l amounts in, and were most abundant in, eggs from yellow females. They wer e also present in brown females but were not detected in second-stage juven iles (J2). The two major egg polypeptides, MEP-I and MEP-II, accounted for more than 50% of the total protein in egg extracts evaluated by sodium dode cyl sulfate-polyacrylamide gel electrophoresis. During development of femal es from the yellow stage to the brown stage, the levels of MEF-I and MEP-II declined at twice the rate as total protein. MEP-I and MEP-II had estimate d molecular masses of 190 kD and 180 kD, respectively, similar to those rep orted for female-specific proteins, vitellins, from free-living nematodes.