Identification and analysis of the major yolk polypeptide from the Caribbean fruit fly, Anastrepha suspensa (loew)

Abstract

AbstractA single major yolk polypeptide (YP) having a molecular mass of approximately 48,000 daltons (Da), was identified in the ovaries and oviposited eggs of the Caribbean fruit fly, Anastrepha suspensa. The polypeptide was partially purified from oviposited eggs using gel permeation and ion‐exchange chromatography. Analysis of YP synthesis in vivo and in tissues cultured in vitro indicated that the ovary was the major site of synthesis with very low levels of YP derived from the adult fat body. Using a monospecific polyclonal antiserum to 48 kDa YP in an immunoblot assay, low levels of vitellogenin were found in female hemolymph; slightly lower levels of an immunoreactive 48‐kDa polypeptide were detectable in male hemolymph. Although YP synthesis was detectable within 12 h after eclosion, the major increase in YP accumulation occurred at 3–4 days posteclosion coincident with the initiation of observable yolk deposition. The physical characteristics of YP from A. suspensa were similar to YPs from other dipterans in terms of molecular mass and antigenicity, yet the tissue‐ and sex‐specific regulation of the YP differed from other dipterans as well as most other insects.