Primary structure and expression of vitellogenin A and vitellogenin B in the desert locust, Schistocerca gregaria (Orthoptera: Acrididae)

Abstract Vitellogenins are the major yolk protein precursors found throughout the animal kingdom. In insects, the primary structures of vitellogenins have been determined in species from most major orders, except for Orthoptera, where only partial sequences have been reported. We amplified and sequenced the complete complementary DNA for two vitellogenins from the desert locust, Schistocerca gregaria (Orthoptera: Acrididae), which code for vitellogenin A and vitellogenin B, two proteins of approximately 200 kDa each. Both proteins are highly expressed at similar rates in adult females only, and their expression can be completely abolished by RNA interference–mediated silencing of the juvenile hormone receptor, methoprene-tolerant (Met). Homologous sequences were inferred from the genome of Locusta migratoria (Orthoptera: Acrididae), yielding complete coding sequences considerably larger than previously published. Vitellogenin A and vitellogenin B from S. gregaria are highly similar to their respective homologues from L. migratoria but show relatively low similarity between each other, suggesting that these genes originated from a common ancestor long before these species diverged.