TRAFFIC OF THE TICK EMBRYO BASIC-PROTEIN DURING EMBRYOGENESIS OF THE CAMEL TICK HYALOMMA-DROMEDARII (ACARI, IXODIDAE)

The tick embryo basic protein (TEBP) is present in the nucleus as a co unterpart of histones at early embryonic stages of the tick Hyalomma d romedarii. The sharp drop in the TEBP nuclear level and elimination of the N-terminal dipeptide (leucine-serine) between days 12 and 15 afte r oviposition suggested the transport of TEBP to the cytoplasm far pro tein turnover. The traffic of TEBP during tick embryogenesis was exami ned. The level of TEBP was detected in the cytoplasm from the differen t embryonic stages by the established enzyme-linked immunosorbent assa y (ELISA) and confirmed by immunoblotting. At day 12, a 2-fold increas e in the cytoplasmic TEBP level coincided with its decrease in the nuc leus. This result indicates that TEBP starts to leave the nucleus for the cytoplasm at day 12. The changes in the cytoplasmic leucine aminop eptidase (LAP)-specific activity were followed during tick embryogenes is. The LAP activity started to increase at day 12 and reached its max imum level at day 21. The enzyme displayed an optimum pH between 7.5 a nd 8.8 and a K-m value of 0.5 mu M for leucine-p-nitroanilide. The inv olvement of the exopeptidase activity in the TEBP turnover after its t ranslocation to the cytoplasm is discussed. Exp App) Acarol 22: 481-49 5 (C) 1998 Kluwer Academic Publishers.