Insect adipokinetic hormones (AKHs) are short peptides produced in the corpora cardiaca and are responsible for mobilizing energy stores from the fat body to the hemolymph. Three related peptides, AKH1, AKH2, and AKH/corazonin-related peptide (ACP) as well as three AKH receptors have been reported in Bombyx mori. AKH1 and AKH2 are specific for the AKHR1 receptor, whereas ACP interacts with the other two AKHRs. To assess the effect of the two silkworm AKHs and ACP in the regulation of energy homeostasis we examined the expression pattern of the three peptides and their receptors as well as their effect on the level of carbohydrates and lipids in the hemolymph. Our results support the hypothesis that only AKH1 and AKH2 peptides together with the AKHR1 receptor are involved in the maintenance of energy homeostasis. Because Bombyx AKHR1 (BmAKHR1) seems to be a true AKHR we generated its mutation. The BmAKHR1 mutant larvae display significantly lower carbohydrate and lipid levels in the hemolymph and reduced sensitivity to starvation. Our study clarifies the role of BmAKHR1 in energy homeostasis.

• Klíčová slova
• BMSK0010951, Bommo-AKH1, Bommo-AKH2, NM_001043584, TALEN, silkworm, targeted mutagenesis,
• MeSH
• bourec růst a vývoj   metabolismus   MeSH
• energetický metabolismus MeSH
• hemolymfa metabolismus   MeSH
• hmyzí hormony genetika   metabolismus   MeSH
• hmyzí proteiny genetika   metabolismus   MeSH
• kyselina pyrrolidonkarboxylová analogy a deriváty   metabolismus   MeSH
• larva metabolismus   MeSH
• lipidy analýza   MeSH
• mutageneze MeSH
• neuropeptidy genetika   metabolismus   MeSH
• oligopeptidy genetika   metabolismus   MeSH
• protein - isoformy genetika   metabolismus   MeSH
• receptory glukagonu genetika   metabolismus   MeSH
• regulace genové exprese MeSH
• sacharidy analýza   MeSH
• signální transdukce * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adipokinetic hormone MeSH Prohlížeč
• corazonin protein, insect MeSH Prohlížeč
• hmyzí hormony MeSH
• hmyzí proteiny MeSH
• kyselina pyrrolidonkarboxylová MeSH
• lipidy MeSH
• neuropeptidy MeSH
• oligopeptidy MeSH
• protein - isoformy MeSH
• receptory glukagonu MeSH
• sacharidy MeSH

Understanding the social evolution leading to insect eusociality requires, among other, a detailed insight into endocrine regulatory mechanisms that have been co-opted from solitary ancestors to play new roles in the complex life histories of eusocial species. Bumblebees represent well-suited models of a relatively primitive social organization standing on the mid-way to highly advanced eusociality and their queens undergo both, a solitary and a social phase, separated by winter diapause. In the present paper, we characterize the gene expression levels of major endocrine regulatory pathways across tissues, sexes, and life-stages of the buff-tailed bumblebee, Bombus terrestris, with special emphasis on critical stages of the queen's transition from solitary to social life. We focused on fundamental genes of three pathways: (1) Forkhead box protein O and insulin/insulin-like signaling, (2) Juvenile hormone (JH) signaling, and (3) Adipokinetic hormone signaling. Virgin queens were distinguished by higher expression of forkhead box protein O and downregulated insulin-like peptides and JH signaling, indicated by low expression of methyl farnesoate epoxidase (MFE) and transcription factor Krüppel homolog 1 (Kr-h1). Diapausing queens showed the expected downregulation of JH signaling in terms of low MFE and vitellogenin (Vg) expressions, but an unexpectedly high expression of Kr-h1. By contrast, reproducing queens revealed an upregulation of MFE and Vg together with insulin signaling. Surprisingly, the insulin growth factor 1 (IGF-1) turned out to be a queen-specific hormone. Workers exhibited an expression pattern of MFE and Vg similar to that of reproducing queens. Males were characterized by high Kr-h1 expression and low Vg level. The tissue comparison unveiled an unexpected resemblance between the fat body and hypopharyngeal glands across all investigated genes, sexes, and life stages.

• Klíčová slova
• caste differentiation, diapause, endocrine glands, hormones, reproduction, social evolution, social insects,
• Publikační typ
• časopisecké články MeSH

BACKGROUND: In models extensively used in studies of aging and extended lifespan, such as C. elegans and Drosophila, adult senescence is regulated by gene networks that are likely to be similar to ones that underlie lifespan extension during dormancy. These include the evolutionarily conserved insulin/IGF, TOR and germ line-signaling pathways. Dormancy, also known as dauer stage in the larval worm or adult diapause in the fly, is triggered by adverse environmental conditions, and results in drastically extended lifespan with negligible senescence. It is furthermore characterized by increased stress resistance and somatic maintenance, developmental arrest and reallocated energy resources. In the fly Drosophila melanogaster adult reproductive diapause is additionally manifested in arrested ovary development, improved immune defense and altered metabolism. However, the molecular mechanisms behind this adaptive lifespan extension are not well understood. RESULTS: A genome wide analysis of transcript changes in diapausing D. melanogaster revealed a differential regulation of more than 4600 genes. Gene ontology (GO) and KEGG pathway analysis reveal that many of these genes are part of signaling pathways that regulate metabolism, stress responses, detoxification, immunity, protein synthesis and processes during aging. More specifically, gene readouts and detailed mapping of the pathways indicate downregulation of insulin-IGF (IIS), target of rapamycin (TOR) and MAP kinase signaling, whereas Toll-dependent immune signaling, Jun-N-terminal kinase (JNK) and Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathways are upregulated during diapause. Furthermore, we detected transcriptional regulation of a large number of genes specifically associated with aging and longevity. CONCLUSIONS: We find that many affected genes and signal pathways are shared between dormancy, aging and lifespan extension, including IIS, TOR, JAK/STAT and JNK. A substantial fraction of the genes affected by diapause have also been found to alter their expression in response to starvation and cold exposure in D. melanogaster, and the pathways overlap those reported in GO analysis of other invertebrates in dormancy or even hibernating mammals. Our study, thus, shows that D. melanogaster is a genetically tractable model for dormancy in other organisms and effects of dormancy on aging and lifespan.

• MeSH
• dlouhověkost genetika   MeSH
• Drosophila melanogaster genetika   fyziologie   MeSH
• genom hmyzu MeSH
• genová ontologie MeSH
• inzulin genetika   MeSH
• regulace genové exprese * MeSH
• rozmnožování genetika   MeSH
• signální transdukce MeSH
• stárnutí genetika   fyziologie   MeSH
• transkriptom genetika   MeSH
• zárodečné buňky metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• inzulin MeSH

Insects, like other organisms, must deal with a wide variety of potentially challenging environmental factors during the course of their life. An important example of such a challenge is the phenomenon of oxidative stress. This review summarizes the current knowledge on the role of adipokinetic hormones (AKH) as principal stress responsive hormones in insects involved in activation of anti-oxidative stress response pathways. Emphasis is placed on an analysis of oxidative stress experimentally induced by various stressors and monitored by suitable biomarkers, and on detailed characterization of AKH's role in the anti-stress reactions. These reactions are characterized by a significant increase of AKH levels in the insect body, and by effective reversal of the markers-disturbed by the stressors-after co-application of the stressor with AKH. A plausible mechanism of AKH action in the anti-oxidative stress response is discussed as well: this probably involves simultaneous employment of both protein kinase C and cyclic adenosine 3',5'-monophosphate pathways in the presence of extra and intra-cellular Ca(2+) stores, with the possible involvement of the FoxO transcription factors. The role of other insect hormones in the anti-oxidative defense reactions is also discussed.

• Klíčová slova
• AKH gene, FoxO, adipokinetic hormones (AKH), anti-oxidative mechanisms, free radicals, insect endocrine system, insecticide, oxidative stress, signaling pathway,
• MeSH
• hmyz metabolismus   MeSH
• hmyzí hormony metabolismus   MeSH
• kyselina pyrrolidonkarboxylová analogy a deriváty   metabolismus   MeSH
• oligopeptidy metabolismus   MeSH
• oxidační stres * MeSH
• signální transdukce MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• adipokinetic hormone MeSH Prohlížeč
• hmyzí hormony MeSH
• kyselina pyrrolidonkarboxylová MeSH
• oligopeptidy MeSH