Identification of endogenous Bsc -PYP-1 from B. schroederi and homologues from other ascarids. (A) Identification of endogenous Bsc-PYP-1 at various developmental stages of B. schroederi. Parasite extracts were prepared essentially as described in Materials and Methods. Eighty micrograms of each parasite extract was separated by SDS-PAGE (10%), and the proteins were then blotted onto a nitrocellulose membrane. Endogenous Bsc-PYP-1 proteins bound to mouse anti-rBsc-PYP-1 serum were detected by NBT/BCIP. Lane 1, rBsc-PYP-1 (5 μg); lane 2, female adult worms; lane 3, liver-stage L3; lane 4, L2; lane 5, embryonated eggs. (B) Expression of Bsc-PYP-1 homologues in ascarid roundworms. Sixty micrograms of protein equivalents of each adult parasite extract were subjected to SDS-PAGE (10%) and then blotted onto a nitrocellulose membrane. Bsc-PYP-1 homologues bound to the anti-serum were detected as mentioned above. Lane 1, rBsc-PYP-1 (5 μg); lane 2, A. lumbricoides; lane 3, B. schroederi; lane 4, A. suum; lane 5, T. canis.