In the ant Ectatomma tuberculatum (Olivier 1792), workers have active ovaries and lay trophic eggs that are eaten by the queen and larvae. Vitellogenins are the main proteins found in the eggs of insects and are the source of nutrients for the embryo in the fertilized eggs and for adults in the trophic eggs. In social insects, vitellogenin titres vary between castes and affect reproductive soci...

Gas chromatographic determinations, bioassays, and radio-labelling experiments show that the juvenile hormone in adult male Hyalophora cecropia is accumulated exclusively in the accessory sex glands. Moths do not store measurable quantities of juvenile hormone if their accessory sex glands are removed shortly after adult eclosion.

The injection of ecdysone (molting hormone) into chironomid larvae is known to result in the stimulation of specific gene activities (increased RNA synthesis). The morphological manifestation of this gene activation is the formation of a puff. Cytological and autoradiographic analysis of several regions of the salivary gland chromosomes of Chironomus tentans revealed that ecdysone also stimulat...

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■ Abstract The mevalonate pathway in insects has two important peculiarities, the absence of the sterol branch and the synthesis of juvenile hormone (JH), that may have influenced the mechanisms of regulation. The data available on these mechanisms indicate that cholesterol does not play a regulatory role and that JH modulates transcript levels of a number of genes of the mevalonate pathway or ...