Asunto(s)
Adaptación Fisiológica , Dopamina/metabolismo , Proteínas de Drosophila/metabolismo , Oogénesis , Estrés Fisiológico , Tirosina/metabolismo , Fosfatasa Alcalina/metabolismo , Animales , Drosophila melanogaster , Ecdisterona/metabolismo , Femenino , Calor , Hormonas Juveniles/metabolismo , Inanición/metabolismoRESUMEN
The effect of the ubiquitous downregulation of insulin receptor (InR) gene expression on the metabolism of juvenile hormone (JH) and dopamine (DA) in young females of D. melanogaster under normal conditions and heat stress is studied. The activity ofJH degradation and alkaline phosphatase (ALP, an enzyme regulating DA synthesis) were used as indicators of JH and DA levels, respectively. We demonstrated that, under normal conditions, the ubiquitous inhibition of the InR gene expression in D. melanogaster females induced an increase in the JH degradation and ALP activity. As we have already shown, this is indicative of the decrease in the concentration of the above hormones. It was also found that the total inactivation of InR does not affect the initiation ofJ H and DA metabolic system response to heat stress; however, it does affect its intensity. Thus, the involvement of the insulin signaling pathway in the regulation of the JH and DA metabolism in Drosophila females was demonstrated in vivo under normal and stress conditions.
Asunto(s)
Regulación hacia Abajo , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Respuesta al Choque Térmico , Hormonas Juveniles/metabolismo , Proteínas Tirosina Quinasas Receptoras/genética , Fosfatasa Alcalina/metabolismo , Animales , Dopamina/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Femenino , Proteínas Tirosina Quinasas Receptoras/metabolismoRESUMEN
The effect of a decreased availability of the D1-like dopamine receptor (DopR) in Drosophila (caused by DopR antagonist added into food) on the juvenile hormone (JH) synthesis rate in young female D. melanogaster has been studied. The JH degradation rate and the alkaline phosphatase (ALP) and tyrosine decarboxylase (TDC) activities were used as indicators of the JH synthesis rate. Treatment of the flies with butaclamol, a specific DopR antagonist, has been demonstrated to increase the JH degradation rate, and the stress reactivity of the system of JH metabolism and decrease the ALP activity and stress reactivity, and increase the TDC activity and stress reactivity. As shown earlier, all this indicates a decrease in the JH synthesis rate in young female drosophila with a decreased DopR availability. It is concluded that the activating effect of dopamine on JH synthesis in Drosophila is mediated by D1-like receptors.
Asunto(s)
Dopamina , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Hormonas Juveniles , Receptores Dopaminérgicos/genética , Fosfatasa Alcalina/metabolismo , Animales , Butaclamol/administración & dosificación , Dopamina/genética , Dopamina/metabolismo , Proteínas de Drosophila/metabolismo , Femenino , Respuesta al Choque Térmico/efectos de los fármacos , Hormonas Juveniles/biosíntesis , Hormonas Juveniles/genética , Hormonas Juveniles/metabolismo , Proteolisis/efectos de los fármacos , Receptores Dopaminérgicos/metabolismo , Tirosina Descarboxilasa/metabolismoRESUMEN
In Drosophila, juvenile hormone (JH) is synthesized de novo in the specialized endocrine gland, corpusallatum (CA). Dopamine (DA) controls JH levels by either stimulating or inhibiting its synthesis and degradation depending on the developmental stage. The present study focuses on the role of D2-like receptors in the regulation of JH synthesis by dopamine. We show that D2-like receptors (DD2R) are expressed in CA cells of Drosophila melanogaster females. In addition, the level of JH production was analyzed in D. melanogaster females with decreased DD2R expression in CA (vs. corresponding control flies) by assessing multiple indices of JH synthesis (JH-hydrolyzing activity and stress reactivity of the system of JH metabolism, activity and stress reactivity of the alkaline phosphatase, activity and stress reactivity of the tyrosine decarboxylase). The differential value obtained for each index suggests increased JH production in female flies that downregulate DD2R. Based on these findings, we postulate that the DA inhibiting effect on the JH synthesis in D. melanogaster is mediated at least in part via D2-like receptors.
Asunto(s)
Corpora Allata/metabolismo , Dopamina/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Hormonas Juveniles/biosíntesis , Receptores de Dopamina D2/metabolismo , Fosfatasa Alcalina/metabolismo , Animales , Animales Modificados Genéticamente , Regulación hacia Abajo , Femenino , Respuesta al Choque Térmico , Tirosina Descarboxilasa/metabolismoRESUMEN
Previous studies have shown that juvenile hormone (JH) regulates dopamine (DA) and octopamine (OA) content in Drosophila, and we have shown the influence of an increase in JH level on DA and OA metabolism in young females of Drosophila virilis and Drosophila melanogaster. Here we investigate the effects of genetic ablation of a subset of cells in the Corpusallatum (CA, endocrine gland synthesizing JH) on the DA levels and activities of alkaline phosphatase (ALP), tyrosine hydroxylase (TH), DA-dependent arylalkylamine N-acetyltransferase (DAT) and tyrosine decarboxylase (TDC) in young D. melanogaster females under normal conditions and upon heat stress (38°Ð¡). We show that ablation of СРcells causes: (1) a decrease in ALP, TH and DAT activities, (2) an increase in DA level and (3) an increase in TDC activity in young females. The CA ablation was also found to modulate ALP, TH and TDC responses to heat stress. Mechanisms of regulation of DA and OA levels by JH in Drosophila females are discussed.
Asunto(s)
Dopamina/biosíntesis , Drosophila melanogaster/metabolismo , Hormonas Juveniles/metabolismo , Octopamina/biosíntesis , Estrés Fisiológico , Fosfatasa Alcalina/metabolismo , Animales , N-Acetiltransferasa de Arilalquilamina/metabolismo , Corpora Allata/citología , Corpora Allata/fisiología , Drosophila melanogaster/genética , Femenino , Calor , Tirosina 3-Monooxigenasa/metabolismo , Tirosina Descarboxilasa/metabolismoRESUMEN
Tissue-specific inhibition of the expression of the D2-like dopamine receptor gene (DD2R) in the corpus allatum (CA), which is a gland that synthesizes the juvenile hormone (JH), was tested for effect on alkaline phosphatase (AP) activity and the intensity of the AP response to heat stress (stress reactivity) in female Drosophila melanogaster. AP activity and AP stress reactivity in transgenic females with lower DD2R expression in the CA were higher than in control flies. A pharmacological elevation in JH increased AP activity in females of the control strains. DD2R was assumed to mediate the inhibitory effect of dopamine of JH synthesis in the CA of D. melanogaster.
Asunto(s)
Fosfatasa Alcalina , Regulación Enzimológica de la Expresión Génica , Hormonas Juveniles , Receptores de Dopamina D2 , Fosfatasa Alcalina/genética , Fosfatasa Alcalina/metabolismo , Animales , Animales Modificados Genéticamente , Corpora Allata/metabolismo , Dopamina/genética , Dopamina/metabolismo , Antagonistas de los Receptores de Dopamina D2 , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Femenino , Expresión Génica , Calor , Hormonas Juveniles/genética , Hormonas Juveniles/metabolismo , Receptores de Dopamina D2/genética , Receptores de Dopamina D2/metabolismo , Estrés Fisiológico/fisiologíaRESUMEN
20-hydroxyecdysone (20E) and the juvenile hormone (JH) have an age-specific effect on total dopamine (DA) content in Drosophila (Gruntenko and Rauschenbach 2008). Earlier we studied the mechanism of influence of 20E and JH on DA metabolism in young females (Rauschenbach et al. in J Insect Physiol 53:587-591, 2007a: Arch Insect Biochem Physiol 65:95-102, 2008a; Gruntenko et al. in Arch Insect Biochem Physiol 72:263-269, 2009). Here we investigate the effects of 20E and JH on the activities of the alkaline phosphatase (ALP), tyrosine hydroxylase (TH) and DA-dependent arylalkylamine N-acetyltransferase (AANAT) in mature females of wild type D. virilis under normal conditions and under heat stress (38°C). 20E feeding of the flies led to a substantial decrease in ALP and TH activities and to an increase in AANAT activity in mature females. JH application resulted in an increasing of ALP and TH activities, but did not influence AANAT activity in mature females. A rise in JH and 20E levels was found to change ALP and TH stress reactivities. Mechanisms of age-specific regulation of DA level by 20E and JH in Drosophila females are discussed.
Asunto(s)
Dopamina/metabolismo , Drosophila/metabolismo , Ecdisterona/metabolismo , Hormonas Juveniles/metabolismo , Envejecimiento/metabolismo , Fosfatasa Alcalina/metabolismo , Animales , N-Acetiltransferasa de Arilalquilamina/metabolismo , Femenino , Tirosina 3-Monooxigenasa/metabolismoAsunto(s)
Drosophila/metabolismo , Hormonas Juveniles/biosíntesis , Receptores de Dopamina D1/metabolismo , Animales , Drosophila/efectos de los fármacos , Drosophila/genética , Femenino , Pergolida/administración & dosificación , Receptores de Dopamina D1/agonistas , Receptores de Dopamina D1/efectos de los fármacos , Tirosina Descarboxilasa/efectos de los fármacos , Tirosina Descarboxilasa/metabolismoAsunto(s)
Fosfatasa Alcalina/metabolismo , Dopamina/metabolismo , Drosophila/enzimología , Drosophila/metabolismo , Receptores de Dopamina D2/metabolismo , Aminas/química , Aminas/metabolismo , Animales , Bromocriptina/farmacología , Femenino , Calor , Levodopa/farmacología , Especificidad de la Especie , Factores de Tiempo , Tiramina/químicaRESUMEN
The effect of a rise in dopamine (DA) level as a result of a mutation, stress or pharmacological treatment on the activity of the enzyme of its synthesis, alkaline phosphatase (ALP) in females of Drosophila virilis and Drosophila melanogaster has been studied. It has been found that regardless of its nature, a rise in DA level has a negative effect on ALP activity, which indicates that DA down-regulates activity of the enzyme. The effects of bromocriptine (an agonist of Drosophila dopamine 2-like receptor (DD2R)) on ALP activity have been studied. ALP activity was found to drop in response to bromocriptine in flies. Conversely ALP activity was increased in flies with reduced DD2R expression (i.e. Actin5C-Gal4>UAS-ds-DD2R RNA-interference flies) vs. corresponding controls (i.e. Actin5C-Gal4>w1118 flies). Bromocriptine treatment of RNAi flies rescues ALP activity to the level typical of Actin5C-Gal4>w1118 flies. A change in DD2R number or availability was found not to prevent the response of ALP to heat stress, but to change the intensity of its response to the stress exposure. The role of D2-like receptors in down-regulation of ALP activity by DA and in ALP response to stressor in Drosophila is discussed.
Asunto(s)
Fosfatasa Alcalina/metabolismo , Dopamina/farmacología , Drosophila/enzimología , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Receptores de Dopamina D2/metabolismo , Animales , Bromocriptina/farmacología , Cromatografía Líquida de Alta Presión , Dihidroxifenilalanina/farmacología , Dopamina/metabolismo , Femenino , Calor , Interferencia de ARN , Receptores de Dopamina D2/agonistas , Especificidad de la Especie , Espectrofotometría Ultravioleta , Estrés Fisiológico/fisiologíaAsunto(s)
Dopamina/metabolismo , Drosophila/efectos de los fármacos , Drosophila/metabolismo , Gonadotropinas/farmacología , Acetiltransferasas/metabolismo , Fosfatasa Alcalina/metabolismo , Animales , Drosophila/crecimiento & desarrollo , Proteínas de Drosophila/metabolismo , Ecdisterona/farmacología , Femenino , Hormonas Juveniles/farmacologíaRESUMEN
The effect of exogenous 20-hydroxyecdysone (20E) and juvenile hormone (JH) on the activities of the tyrosine decarboxylase (TDC), the first enzyme in octopamine (OA) synthesis, has been studied in young females of wild type D. virilis and D. melanogaster under normal and heat stress (38 degrees C) conditions. Flies fed 20E expressed increased TDC activity in both species. JH application decreased TDC activity in both species. A rise in JH and 20E levels did not prevent a TDC response to heat stress, but changed the response intensity. A long-term increase in JH titre had no effect on the activity of main OA catabolyzing enzyme, arylalkylamine N-acetyltransferase, in females of both species. A possible mechanism of regulation of OA levels by 20E and JH in Drosophila females is discussed.
Asunto(s)
Drosophila/efectos de los fármacos , Drosophila/fisiología , Ecdisterona/farmacología , Hormonas Juveniles/farmacología , Octopamina/metabolismo , Animales , N-Acetiltransferasa de Arilalquilamina/metabolismo , Femenino , Calor , Factores de Tiempo , Tirosina Descarboxilasa/metabolismoRESUMEN
Alkaline phosphatase (AP) and N-acetyltransferase (NAT) activities were studied in 1-day-old Drosophila melanogaster females of the apterous56f (ap56f) strain, having an elevated level of the juvenile hormone (JH) and a decreased level of dopamine as a result of the mutation, and in the Canton S ancestral wild-type strain in the normal conditions and upon an experimental increase in JH titer. The AP and NAT activities in ap56f females were significantly lower than in Canton S females in the norm. JH application increased the AP activity of mutant females to the level characteristic to JH-treated wild-type females.
Asunto(s)
Acetiltransferasas/genética , Fosfatasa Alcalina/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/enzimología , Proteínas de Homeodominio/genética , Factores de Transcripción/genética , Acetiltransferasas/metabolismo , Fosfatasa Alcalina/metabolismo , Animales , Animales Recién Nacidos , Dopamina/metabolismo , Femenino , Hormonas Juveniles/metabolismo , Proteínas con Homeodominio LIM , MutaciónRESUMEN
The effect of an experimentally increased octopamine content (feeding flies with OA) on the levels of juvenile hormone (JH) degradation, dopamine (DA), and 20-hydroxyecdysone (20E) contents, oogenesis, and fecundity of wild type Drosophila flies has been studied. OA feeding of the flies was found to (1) cause a considerable decrease in JH degradation in females, but not males, of D. melanogaster and D. virilis; (2) have no effect on DA content in D. melanogaster and D. virilis; (3) increase 20E contents in D. virilis females; (4) decrease to a large extent the number of vitellogenic (stages 8-10) and mature (stage 14) oocytes in D. virilis; and (5) decrease the fecundity of D. melanogaster and D. virilis. A possible mechanism of action of OA as a neurohormone on the reproductive function of Drosophila is discussed.