VITELLOGENESIS IN A PRIMITIVE TERMITE, ZOOTERMOPSIS ANGUSTICOLLIS (HAGEN) (HODOTERMITIDAE)

¹ Department of Zoology, University of Massachusetts, Amherst, Massachusetts 01003

1. Vitellogenesis was studied in the primitive termite Zootermopsis angusticollis. Quantitative (rocket) immunoelectrophoresis was used to demonstrate two immunologically distinct sex-specific hemolymph proteins, vitellogenins, in female reproductives which were immunologically identical in neotenic and adult reproductive serum and in egg yolk from neotenic reproductives.

2. The vitellogenins are not detectable in hemolymph of neotenic reproductives by our methods until seven to nine days after the neotenic molt. A marked increase in oocyte volume was observed beginning six to eight days later and oviposition occurred approximately 25 days (range 22 to 30 days) after the neotenic molt. Presumably, vitellogenin production in this primitive termite occurs outside the ovary, as in the majority of other insects studied. However, the exact site of synthesis of this protein has not yet been demonstrated in the Isoptera.

3. Acrylamide gel electrophoresis at pH 7.5 of TEAE-cellulose purified egg yolk protein also demonstrated the existence of two distinct vitellins. SDS-gel electrophoresis of purified egg yolk protein showed that the two vitellins are composed of at least three subunits whose molecular weights were estimated to be 112,000, 89,000 and 71,000 Daltons.