Correlation between haemolymph juvenile hormone titre, corpus allatum volume, and corpus allatum in vivo and in vitro activity during oocyte maturation in a cockroach (Nauphoeta cinerea).

Abstract

Characteristic changes in haemolymph juvenile hormone (JH) titre, corpus allatum (c.a.) volume, and c.a. in vivo and in vitro activity occur during the oocyte maturation phase of the ovoviviparous cockroach Nauphoeta cinerea. When oocyte growth proceeds at its highest rate the c.a. volume and in vitro activity as well as the JH titre in haemolymph are highest, indicating a positive correlation between these parameters. However, no correlation between c.a. in vitro activity and haemolymph JH titre is detectable if individual females in a stage of rapid oocyte growth are investigated. This suggests that JH is possibly synthesized in pulses and not continuously. The in vivo activity of transplanted c.a. is different from their in vitro activity and it seems that the in vitro activity reflects the rate of JH production at the time of dissection while the in vivo activity is indicative of the JH-producing potential under certain influences of the surrounding medium.