Article

A role for juvenile hormone in the prepupal development of Drosophila melanogaster

Janelia Farm Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA.
Development (Impact Factor: 6.46). 02/2010; 137(7):1117-26. DOI: 10.1242/dev.037218
Source: PubMed

ABSTRACT

To elucidate the role of juvenile hormone (JH) in metamorphosis of Drosophila melanogaster, the corpora allata cells, which produce JH, were killed using the cell death gene grim. These allatectomized (CAX) larvae were smaller at pupariation and died at head eversion. They showed premature ecdysone receptor B1 (EcR-B1) in the photoreceptors and in the optic lobe, downregulation of proliferation in the optic lobe, and separation of R7 from R8 in the medulla during the prepupal period. All of these effects of allatectomy were reversed by feeding third instar larvae on a diet containing the JH mimic (JHM) pyriproxifen or by application of JH III or JHM at the onset of wandering. Eye and optic lobe development in the Methoprene-tolerant (Met)-null mutant mimicked that of CAX prepupae, but the mutant formed viable adults, which had marked abnormalities in the organization of their optic lobe neuropils. Feeding Met(27) larvae on the JHM diet did not rescue the premature EcR-B1 expression or the downregulation of proliferation but did partially rescue the premature separation of R7, suggesting that other pathways besides Met might be involved in mediating the response to JH. Selective expression of Met RNAi in the photoreceptors caused their premature expression of EcR-B1 and the separation of R7 and R8, but driving Met RNAi in lamina neurons led only to the precocious appearance of EcR-B1 in the lamina. Thus, the lack of JH and its receptor Met causes a heterochronic shift in the development of the visual system that is likely to result from some cells 'misinterpreting' the ecdysteroid peaks that drive metamorphosis.

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    • "For example, several studies have reported that juvenile hormones (JHs) have significant effects on some ecdysteroidogenic enzyme genes and torso in the PG of B. mori (Yamanaka et al. 2007;Young et al. 2012;Ogihara et al. 2015). This is less likely the case with the PG in D. melanogaster, considering that JHs appear not to have the typical " status quo " effect on larval development in D. melanogaster (Niwa et al. 2008;Liu et al. 2009;Riddiford et al. 2010;Ono 2014;Wen et al. 2015). Furthermore, some prothoracicotropic factors might primarily control translation, but not transcription, in the PG. "
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    • "Insect growth and development are controlled by two major hormones, juvenile hormones and ecdysteroids (Delanoue et al., 2010; Kozlova and Thummel, 2003; Riddiford et al., 2010). The titers of both hormones are precisely coordinated by biosynthesis and metabolism pathways and the levels of these hormones are tightly correlated with their regulation of physiological and developmental processes. "

    Full-text · Article · Aug 2014 · Insect Biochemistry and Molecular Biology
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    • "Insect growth and development are controlled by two major hormones, juvenile hormones and ecdysteroids (Delanoue et al., 2010; Kozlova and Thummel, 2003; Riddiford et al., 2010). The titers of both hormones are precisely coordinated by biosynthesis and metabolism pathways and the levels of these hormones are tightly correlated with their regulation of physiological and developmental processes. "
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