Antigenic differences among the life cycle stages of Oesophagostomum radiatum.

Maturation of Oesophagostomum radiatium is characterised by production of different proteins in all the life cycle stages that occur within the bovine host. One-dimensional sodium dodecyl sulphate-polyacrylamide gels stained for total protein, showed that fourth stage larvae (L4) and adult worms have many proteins in common but L4 has a major additional protein (82,000 D); third stage larvae have many different proteins. Analysis of the proteins of each life cycle stage by Western blotting with sera from naturally infected calves showed that each life cycle stage had specific antigenic proteins. The major protein unique to L4 was identified as a developmentally regulated antigen.