Molecular cloning, developmental pattern and tissue expression of 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase of the cockroach <i>Blattella germanica</i>

Martínez-González, José de Jesús; Buesa, Carlos; Piulachs, María‐Dolors; Bellés, Xavier; Hegardt, Fausto G.

doi:10.1111/j.1432-1033.1993.tb17753.x

Cited by 41 publications

(32 citation statements)

References 49 publications

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“…In other insects, such as cockroaches, the hydroxymethylglutarylCoA reductase enzyme has been shown to be present in other tissues (27), and, consequently, other putative side effects on tissues besides the corpora allata could not be excluded. To confirm that the observed fluvastatin effect on locomotor activity is conveyed by JH, we used methoprene, a JH analog, to reverse the fluvastatin effect.…”

Section: Ingestion Of Fluvastatin a Jh Biosynthesis Inhibitor Mimicmentioning

confidence: 99%

Neuroendocrine control of a sexually dimorphic behavior by a few neurons of the pars intercerebralis in Drosophila

Belgacem

Martin

2002

Proc. Natl. Acad. Sci. U.S.A.

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In Drosophila, locomotor activity is sexually dimorphic and the brain area controlling this dimorphism has been mapped. The neurons of the pars intercerebralis (PI) have been suggested to participate in such differences between males and females. However, the precise physical nature of the dimorphism, the identity of the PI neurons involved, and the nature of the neuronal signal coding the dimorphism remain unknown. In this study, we used a video-tracking paradigm to characterize further the pattern of locomotor activity in Drosophila. We show that the number of activity͞inactivity periods (start͞stop bouts) is also sexually dimorphic, and that it can be genetically feminized in males. Moreover, the transplantation of PI neurons from a female, or of feminized PI neurons from a donor male into a receiver wild-type male is sufficient to induce the feminization of locomotor behavior, confirming that this tiny cluster of Ϸ10 neurons is directly responsible for the sexual dimorphism in locomotor activity. Finally, feeding males with fluvastatin, a juvenile hormone (JH) inhibitor, also led to start͞stop feminization, and this effect is reversible by the simultaneous application of methoprene, a JH analog, suggesting the existence of a neuroendocrine control, by JH, of such behavioral dimorphism. Invertebrates and vertebrates show sexually dimorphic behaviors, and it has been suggested that males and females differ in the brain structures controlling such behavioral differences (1-4). Such sex differences have often been used as a way of studying how brain structure contributes to brain function. However, although many sexually dimorphic neural structures have been described (2-4), very few studies have yet demonstrated the direct involvement of a brain structure in a sexually dimorphic behavior (5, 6) and still less a behavior expressed in a nonsexual context. We recently showed that Drosophila locomotor activity is sexually dimorphic (7) outside any sexual context. We could abolish this behavioral dimorphism and create males with a female-like activity profile by genetic manipulations (8). Briefly, we used a UAS-transformer transgene (UAS-tra; ref. 9), the feminizing action of which has been shown to be cell-autonomous (10-12), under the control of different brainspecific enhancer trap P[Gal4] lines. This first study suggested strongly that a few neurons located in the mid-anterior part of the pars intercerebralis (PI) might participate in the control of this sexually dimorphic behavior (8). However, because in this previous study the fly was observed in a small tube, the locomotor activity was indirectly quantified when the fly crossed an infra-red light-gate. As a result, the precise locomotor parameters that accounted for the sexual difference could not be elucidated. Furthermore, the involvement of the PI neurons was indirectly deduced on the basis of a genetic ablation, and the molecular mechanisms linking those few PI neurons to the sexually dimorphic behavior remained to be identified. In this study, we develo...

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Section: Ingestion Of Fluvastatin a Jh Biosynthesis Inhibitor Mimicmentioning

confidence: 99%

Neuroendocrine control of a sexually dimorphic behavior by a few neurons of the pars intercerebralis in Drosophila

Belgacem

Martin

2002

Proc. Natl. Acad. Sci. U.S.A.

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“…Given that BgTOR RNAi treatment resulted in a dramatic reduction of JH production, we studied the knockdown effects on the expression of HMG-CoA synthase-1 and -2 (18,19) and HMG-CoA reductase (20) in CA and fat body. In this case, we were interested not only in the mere modification of mRNA levels, but also in the relative contribution of each of these enzymes in both tissues.…”

Section: Expression Patterns Of Bgtor and Other Mrnas Related Tomentioning

confidence: 99%

Target of Rapamycin (TOR) Mediates the Transduction of Nutritional Signals into Juvenile Hormone Production

Maestro

Cobo

Bellés

2009

Journal of Biological Chemistry

110

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Anautogeny is a reproductive strategy by which females do not reproduce until they feed. Therefore, nutritional signals must inform the reproductive tissues, and cells that the organism has reached a nutritional status suitable for triggering reproductive processes. One of the possible pathways involved in anautogeny is the "target of rapamycin" (TOR) pathway, which has been described as connecting the nutritional status with growth, proliferation, and cancer. The German cockroach, Blattella germanica, is an anautogenous species whose vitellogenesis is governed by juvenile hormone. In the present report, we describe the cloning of TOR cDNA from B. germanica (BgTOR). Expression studies showed that BgTOR is expressed in adult female corpora allata and fat body. BgTOR knockdown using systemic RNAi in vivo produced a severe inhibition of juvenile hormone synthesis in adult female corpora allata, together with a reduction of mRNA levels corresponding to 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase-1, HMG-CoA synthase-2, and HMG-CoA reductase. In addition, there was a reduction of vitellogenin mRNA in the fat body, and ovaries did not grow. Analysis of TOR expression in corpora allata of fed and starved females suggested that TOR is not regulated at the transcriptional level. Nevertheless, there was a reduction in HMG-CoA synthases and reductase mRNA in corpora allata (but not in the fat body) of starved females, together with a dramatic reduction of juvenile hormone production and ovary development. Taken together, our results indicate that TOR knockdown mimics starvation in terms of corpora allata activity, and suggest that nutritional signals that activate juvenile hormone biosynthesis and vitellogenin production are mediated by the TOR pathway.

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“…The minute size of the CA has been a major obstacle to classical biochemical approaches such as enzyme purification or even the preparation of subcellular membrane fractions (2,3). Molecular cloning of the enzymes involved in the early steps of JH biosynthesis has taken advantage of the conservation of the mevalonate pathway between vertebrates and insects (4), but this option is not available for the later, JH-specific steps.…”

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confidence: 99%

CYP15A1, the cytochrome P450 that catalyzes epoxidation of methyl farnesoate to juvenile hormone III in cockroach corpora allata

Helvig

Koener

Unnithan

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

224

237

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The molecular analysis of insect hormone biosynthesis has long been hampered by the minute size of the endocrine glands producing them. Expressed sequence tags from the corpora allata of the cockroach Diploptera punctata yielded a new cytochrome P450, CYP15A1. Its full-length cDNA encoded a 493-aa protein that has only 34% amino acid identity with CYP4C7, a terpenoid -hydroxylase previously cloned from this tissue. Heterologous expression of the cDNA in Escherichia coli produced >300 nmol of CYP15A1 per liter of culture. After purification, its catalytic activity was reconstituted by using phospholipids and house fly P450 reductase. CYP15A1 metabolizes methyl (2E,6E)-3,7,11-trimethyl-2,6-dodecatrienoate (methyl farnesoate) to methyl (2E,6E)-(10R)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate [juvenile hormone III, JH III] with a turnover of 3-5 nmol͞min͞nmol P450. The enzyme produces JH III with a ratio of Ϸ98:2 in favor of the natural (10R)-epoxide enantiomer. This result is in contrast to other insect P450s, such as CYP6A1, that epoxidize methyl farnesoate with lower regio-and stereoselectivity. RT-PCR experiments show that the CYP15A1 gene is expressed selectively in the corpora allata of D. punctata, at the time of maximal JH production by the glands. We thus report the cloning and functional expression of a gene involved in an insectspecific step of juvenile hormone biosynthesis. Heterologously expressed CYP15A1 from D. punctata or its ortholog from economically important species may be useful in the design and screening of selective insect control agents.

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Molecular cloning, developmental pattern and tissue expression of 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase of the cockroach Blattella germanica

Cited by 41 publications

References 49 publications

Neuroendocrine control of a sexually dimorphic behavior by a few neurons of the pars intercerebralis in Drosophila

Neuroendocrine control of a sexually dimorphic behavior by a few neurons of the pars intercerebralis in Drosophila

Target of Rapamycin (TOR) Mediates the Transduction of Nutritional Signals into Juvenile Hormone Production

CYP15A1, the cytochrome P450 that catalyzes epoxidation of methyl farnesoate to juvenile hormone III in cockroach corpora allata

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