Ecdysteroids reproduction

Barker, G., Chitwood, D. and Rees, H. (1990) Ecdysteroids in helminths and annelids. Invertebrate Reproduction and Development 18, 1—11. 

Another aspect of the sex pheromone communication system concerns the endogenous signals that control pheromone production and release from the emitting insect. A number of hormones have been found to be involved in the control of pheromone production in various insect species (18). Juvenile hormone was found to induce vitellogenesis and sex pheromone production in some cockroach and beetle species. However, ecdysteroids were found to be involved in regulating reproductive processes, including vitellogenin synthesis, in dipteran species. 

A recent study differentiated the role of JH and ecdysteroids in the ant Streblognathus peetersi. Ecdysone was correlated with dominant ants and reproduction while JH was more commonly associated with low-ranking ants and sterility (Brent et al., 2006). 

A detailed summary of the roles of ecdysteroids during arthropod development and reproduction is beyond the scope of this review. This aspect has been extensively reviewed elsewhere [1,2,6-9],... 

To date, interest in the ecdysteroids has focused primarily on their role in insect molting and metamorphosis and it is perhaps somewhat unfortunate that bioassays for ecdysteroid activity have been restricted almost exclusively to evaluating their effect on the molting process. It now appears probable that molting is just one of several important regulatory functions (e.g., embryogenesis, reproduction) performed by the ecdysteroids and that we are only just beginning to scratch the surface of an insect steroid system that is equally as complex as that in vertebrate species. 

The molting and other hormonal activities of the ecdysteroids are, of course, modulated by the titer of the insect juvenile hormone and the two materials typically function in close concert with one another in dictating insect molting and metamorphosis as well as in reproductive maturation (21). 

Brassinosteroids are a family of hormones found in plants in which they are potent growth-promoters (reviews I, 2). Ecdysteroids on the other hand are a group of hormones occurring in all phyla of protostomian animals. In arthropods they are involved in the control of growth, morphogenesis, and reproduction (reviews 3, 4). While brassinosteroids have been detected in plants only, ecdyster-... 

Two groups of hormones regulate development and reproduction in insects, namely the ecdysteroids and the JHs. In crustaceans too, ecdysteroids are involved in the hormonal control of growth, and a chemical compound, which is similar to the JHs of insects, is present and thought to play a role in crustacean reproduction and development. The insect JH is a species-specific acyclic sesquiterpenoid epoxide, which is synthesized in a pair of retrocerebral epithelial organs called the corpora allata (CA see Fig. 1). In decapod crustaceans, MF is the unepoxidated form of the insect JH III and it is synthesized and secreted from the MOs (see Section 3.2.4). 

Ecdysteroids likely play a role in female crustacean reproduction. Various ecdys-teroids have been identified in follicle cells and oocytes of brine shrimp, amphi-pods, crabs, crayfish, and shrimp. The function of these ovarian ecdysteroids in crustaceans remains uncertain. Some correlations between vitellogenesis and hemolymph ecdysteroid titers have been reported. For unknown reasons, the effects of ecdysteroid injections or in vitro incubations on vitellogenesis have been either inhibitory or stimulatory. 

Subramoniam T (2000) Crustacean ecdysteroids in reproduction and embryogenesis. Comp Biochem Physiol C 125 135-156... 

---