Behavioral Endocrinology: Juvenile hormone mediation of behavior
The reproductive cycle in cockroaches is regulated by several lipidic and peptide hormones, with juvenile hormone III (JH III), a sesquiterpenoid, playing a pivotal role as the adult female gonadotropic hormone. JH III stimulates the fat body to produce vitellogenin - a yolk protein precursor - and the oocytes to endocytose vitellogenin. It also stimulates the production of egg case proteins by the accessory glands of females and of spermatophore proteins by the male accessory sex glands. JH also causes an elevation in food intake in vitellogenic females. In some species, behavioral and physiological events related to mate-finding and sexual receptivity are also regulated in a coordinated manner by this vital hormone. Cockroaches have long served as a model system for studies of invertebrate endocrinology and neuroethology. Therefore, a wealth of information is available about endocrine regulation of reproduction, which provides a useful foundation for our studies. Our investigations have addressed the following questions:
- What environmental cues affect JH production in the adult female cockroach?
- How does grouping ("social facilitation”) elevate the level of JH in vitellogenic females?
- What cellular events within the corpora allata (endocrine glands that produce JH) mediate increases and decreases in JH release?
- JH titers affect pheromone production and sexual receptivity. How?
- How is feeding behavior modulated by JH levels?
- How is JH maintained at low levels during gestation and what signals release the corpora allata to produce JH at parturition (birth)?
Various External and internal signals are integrated in the
brain, which
then regulates synthesis and release of JH III
We have also used this information as the basis for recommendations to Pest Management Professionals about proper deployment of JH analogs in pest control.
Supported by:
Blanton J. Whitmire Endowment
W. M. Keck Center for Behavioral Biology