Changes in Vitellogenic Proteins During The Reproductive Cycle of The Female Tick, Argas persicus

Abstract

Proteins in the freshly deposited eggs of mated fed female Argas persicus were electrophoretically separated into twelve fractions or egg vitellins (EVts) with Mwt of 24.72-131.45kD. One fraction (131.45kD) existed only in the egg and eleven were exogenous EVts with extraovarian counterparts (vitellogenins) in the hemolymph (HL). Six of them were common EVts (24.72-65.53kD) with similar counterparts in the HL of both male and female and five were female-specific EVts (78.65-112.92 and 48.67kD) with similar counterparts only in the female HL. Eleven vitellogenins (Vgs) and ten exogenous vitellins (Vts) with similar electrophoretic mobilities to EVts were identified in the HL and ovaries, respectively, of mated females. The number and percent amount of the detected vitellogenic protein fractions varied in the different physiological states (10) studied (unfed, 0-7 and 20 day after feeding, daf). Generally, there was an increase of the two parameters in ovary vitellin fractions (with appearance of new Vts) and a decrease in HL vitellogenin fractions during vitellogenesis at the late period of the female reproductive cycle (4-7 and 20 daf). The obtained results support the concept of the uptake of hemolymph Vgs by the ovaries and deposition as Vts in the oocytes during vitellogenesis which may extend till the end of the oviposition period (20 daf) in the female A.persicus.