Molecular endocrine model mechanism of insect metamorphosis and jh acid as the key regulator

Metamorphosis comprise dramatic transformation in shape and function of organs, tissues and individual cells. According to the classical theory of the hormonal control of insect metamorphosis, ecdysteroids initiates a molt independent on the titer of JH. However a few observations earlier indicate that tissues must first acquire competence in the presence of JH acid alone is not sufficient for the metamorphic response to ecdysteroid. JHacid is an inactive precursor and metabolite of JH actually induces cells to become competent to undergo metamorphoses, whereas ecdysteroid merely stabilizes this commitment and facilitates the expression of this state of development program.The model system used in this project is the common Mormon butterfly Papillio polytes is a major pest of Rutaceous plants. Metamorphosis especially molting behavior in insects is known to be governed by specific dermal glands known as Version’s glands. Ecdysteroid induces and coordinates the molting process and JH determines the nature of moult. JH acid is an inactive precursor and metabolite of juvenile hormone (JH) that induces cells to become competent to undego metamorphosis, whereas ecdysteroid merely stabilizes this commitment that facilitates the expression of this state of developmental programme.Verson’s glands that are found specifically in lepidopteran insects are paired dermal glands of epidermal derivatives which contribute a protective layer to the newly formed cuticle or might has defensive function.In the present study localization of Version’s glands were done The specific role of JH metabolite, the JH acid in the induction of metamorphic competence were examined. Elucidation of the fundamental mechanism and interaction of insect endocrine molecules during insect metamorphosis were also explained.