Data/hora: 03/06/2024 07:47:53

Provedor de dados: | Brazilian Journal of Medical and Biological Research
País: | Brazil
Título: | Insect juvenile hormone: from "status quo" to high society
Autores: | Hartfelder,K.
Data: | 2000-02-01
Ano: | 2000
Palavras-chave: | Juvenile hormone; Corpora allata; Metamorphosis; Insect reproduction; Polymorphism; Honey bee.
Resumo: | Juvenile hormone (JH) exerts pleiotropic functions during insect life cycles. The regulation of JH biosynthesis by neuropeptides and biogenic amines, as well as the transport of JH by specific binding proteins is now well understood. In contrast, comprehending its mode of action on target organs is still hampered by the difficulties in isolating specific receptors. In concert with ecdysteroids, JH orchestrates molting and metamorphosis, and its modulatory function in molting processes has gained it the attribute "status quo" hormone. Whereas the metamorphic role of JH appears to have been widely conserved, its role in reproduction has been subject to many modifications. In many species, JH stimulates vitellogenin synthesis and uptake. In mosquitoes, however, this function has been transferred to ecdysteroids, and JH primes the ecdysteroid response of developing follicles. As reproduction includes a variety of specific behaviors, including migration and diapause, JH has come to function as a master regulator in insect reproduction. The peak of pleiotropy was definitely reached in insects exhibiting facultative polymorphisms. In wing-dimorphic crickets, differential activation of JH esterase determines wing length. The evolution of sociality in Isoptera and Hymenoptera has also extensively relied on JH. In primitively social wasps and bumble bees, JH integrates dominance position with reproductive status. In highly social insects, such as the honey bee, JH has lost its gonadotropic role and now regulates division of labor in the worker caste. Its metamorphic role has been extensively explored in the morphological differentiation of queens and workers, and in the generation of worker polymorphism, such as observed in ants.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000200003
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2000000200003
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.33 n.2 2000
Fonte: | info:eu-repo/semantics/openAccess