BACKGROUND: Epigenetic modifications including DNA methylation and post-translational modifications of histones are known to regulate gene expression. Antagonistic activities of histone acetyltransferases (HATs) and histone deacetylases (HDACs) mediate transcriptional reprogramming during insect development as shown in Drosophila melanogaster and other insects. Juvenile hormones (JH) play vital roles in the regulation of growth, development, metamorphosis, reproduction and other physiological processes. However, our current understanding of epigenetic regulation of JH action is still limited. Hence, we studied the role of CREB binding protein (CBP, contains HAT domain) and Trichostatin A (TSA, HDAC inhibitor) on JH action. RESULTS: Exposure of Tribolium castaneum cells (TcA cells) to JH or TSA caused an increase in expression of Kr-h1 (a known JH-response gene) and 31 or 698 other genes respectively. Knockdown of the gene coding for CBP caused a decrease in the expression of 456 genes including Kr-h1. Interestingly, the expression of several genes coding for transcription factors, nuclear receptors, P450 and fatty acid synthase family members that are known to mediate JH action were affected by CBP knockdown or TSA treatment. CONCLUSIONS: These data suggest that acetylation and deacetylation mediated by HATs and HDACs play an important role in JH action.
- Klíčová slova
- FOXO Tribolium and TcA cells, HAT, HDAC, Kr-h1,
- MeSH
- acetylace MeSH
- dvouvláknová RNA metabolismus MeSH
- epigeneze genetická účinky léků MeSH
- hmyzí proteiny antagonisté a inhibitory genetika metabolismus MeSH
- kyseliny hydroxamové farmakologie MeSH
- protein vázající CREB antagonisté a inhibitory genetika metabolismus MeSH
- RNA interference MeSH
- Tribolium účinky léků růst a vývoj metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- dvouvláknová RNA MeSH
- hmyzí proteiny MeSH
- kyseliny hydroxamové MeSH
- protein vázající CREB MeSH
- trichostatin A MeSH Prohlížeč
Juvenile hormones (JH) and ecdysteroids regulate many biological and metabolic processes. CREB-binding protein (CBP) is a transcriptional co-regulator with histone acetyltransferase (HAT) activity. Therefore, CBP is involved in activation of many transcription factors that regulate expression of genes associated with postembryonic development in insects. However, the function of CBP in JH action in insects is not well understood. Hence, we studied the role of CBP in JH action in the red flour beetle, Tribolium castaneum and the Tribolium cell line. CBP knockdown caused a decrease in JH induction of genes, Kr-h1, 4EBP and G13402 in T. castaneum larvae, adults and TcA cells whereas, Trichostatin A [TSA, a histone deacetylase (HDAC) inhibitor] induced the expression of these JH-response genes. Western blot analysis with specific antibodies revealed the requirement of CBP for the acetylation of H3K18 and H3K27 in both T. castaneum and TcA cells. Chromatin immunoprecipitation (Chip) assays showed the importance of CBP-mediated acetylation of H3K27 for JH induction of Kr-h1, 4EBP, and G13402 in TcA cells. These data suggest that CBP plays an important role in JH action in the model insect, T.castaneum.
- MeSH
- acetylace MeSH
- genový knockout MeSH
- histony metabolismus MeSH
- hmyzí proteiny genetika metabolismus MeSH
- juvenilní hormony farmakologie MeSH
- protein vázající CREB genetika metabolismus MeSH
- Tribolium genetika růst a vývoj metabolismus MeSH
- vývojová regulace genové exprese účinky léků MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
- Názvy látek
- histony MeSH
- hmyzí proteiny MeSH
- juvenilní hormony MeSH
- protein vázající CREB MeSH
BACKGROUND: Juvenile hormones (JH) and ecdysteroids control postembryonic development in insects. They serve as valuable targets for pest management. Hence, understanding the molecular mechanisms of their action is of crucial importance. CREB-binding protein (CBP) is a universal transcriptional co-regulator. It controls the expression of several genes including those from hormone signaling pathways through co-activation of many transcription factors. However, the role of CBP during postembryonic development in insects is not well understood. Therefore, we have studied the role of CBP in postembryonic development in Tribolium, a model coleopteran insect. RESULTS: CBP is ubiquitously expressed in the red flour beetle, Tribolium castaneum. RNA interference (RNAi) mediated knockdown of CBP resulted in a decrease in JH induction of Kr-h1 gene expression in Tribolium larvae and led to a block in their development. Moreover, the injection of CBP double-stranded RNA (dsRNA) showed lethal phenotypes within 8 days of injection. RNA-seq and subsequent differential gene expression analysis identified CBP target genes in Tribolium. Knockdown of CBP caused a decrease in the expression of 1306 genes coding for transcription factors and other proteins associated with growth and development. Depletion of CBP impaired the expression of several JH response genes (e.g., Kr-h1, Hairy, early trypsin) and ecdysone response genes (EcR, E74, E75, and broad complex). Further, GO enrichment analyses of the downregulated genes showed enrichment in different functions including developmental processes, pigmentation, anatomical structure development, regulation of biological and cellular processes, etc. CONCLUSION: These data suggest diverse but crucial roles for CBP during postembryonic development in the coleopteran model insect, Tribolium. It can serve as a target for RNAi mediated pest management of this stored product pest.
- Klíčová slova
- CBP, Ecdysone, Juvenile hormone, Kr-h1, RNA seq, RNAi, Tribolium,
- MeSH
- exprese genu MeSH
- hmyzí proteiny antagonisté a inhibitory genetika metabolismus fyziologie MeSH
- juvenilní hormony farmakologie MeSH
- larva genetika metabolismus MeSH
- protein vázající CREB antagonisté a inhibitory genetika metabolismus fyziologie MeSH
- RNA interference MeSH
- Tribolium genetika růst a vývoj metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
- Názvy látek
- hmyzí proteiny MeSH
- juvenilní hormony MeSH
- protein vázající CREB MeSH
The structured population LPA model is studied. The model describes flour beetle (Tribolium) population dynamics of four stage populations: eggs, larvae, pupae and adults with cannibalism between these stages. We concentrate on the case of non-zero cannibalistic rates of adults on eggs and adults on pupae and no cannibalism of larvae on eggs, but the results can be numerically continued to non-zero cannibalism of larvae on eggs. In this article two-parameter bifurcations in LPA model are analysed. Various stable and unstable invariant sets are found, different types of hysteresis are presented and abrupt changes in dynamics are simulated to explain the complicated way the system behaves near two-parameter bifurcation manifolds. The connections between strong 1:2 resonance and Chenciner bifurcations are presented as well as their very significant consequences to the dynamics of the Tribolium population. The hysteresis phenomena described is a generic phenomenon nearby the Chenciner bifurcation or the cusp bifurcation of the loop.
- Klíčová slova
- Chenciner bifurcation, LPA model, Population dynamics, Strong 1:2 resonance, Two-parameter bifurcations,
- MeSH
- biologické modely * MeSH
- chování zvířat MeSH
- kanibalismus MeSH
- matematické pojmy MeSH
- nelineární dynamika MeSH
- populační dynamika statistika a číselné údaje MeSH
- Tribolium růst a vývoj fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Metamorphosis of holometabolous insects, an elaborate change of form between larval, pupal and adult stages, offers an ideal system to study the regulation of morphogenetic processes by hormonal signals. Metamorphosis involves growth and differentiation, tissue remodeling and death, all of which are orchestrated by the morphogenesis-promoting ecdysteroids and the antagonistically acting juvenile hormone (JH), whose presence precludes the metamorphic changes. How target tissues interpret this combinatorial effect of the two hormonal cues is poorly understood, mainly because JH does not prevent larval-pupal transformation in the derived Drosophila model, and because the JH receptor is unknown. We have recently used the red flour beetle Tribolium castaneum to show that JH controls entry to metamorphosis via its putative receptor Methoprene-tolerant (Met). Here, we demonstrate that Met mediates JH effects on the expression of the ecdysteroid-response gene Broad-Complex (BR-C). Using RNAi and a classical mutant, we show that Tribolium BR-C is necessary for differentiation of pupal characters. Furthermore, heterochronic combinations of retarded and accelerated phenotypes caused by impaired BR-C function suggest that besides specifying the pupal fate, BR-C operates as a temporal coordinator of hormonally regulated morphogenetic events across epidermal tissues. Similar results were also obtained when using the lacewing Chrysopa perla (Neuroptera), a member of another holometabolous group with a primitive type of metamorphosis. The tissue coordination role of BR-C may therefore be a part of the Holometabola groundplan.
- MeSH
- biologická proměna * MeSH
- biologické modely MeSH
- brouci růst a vývoj metabolismus ultrastruktura MeSH
- hmyzí proteiny chemie genetika metabolismus MeSH
- juvenilní hormony metabolismus MeSH
- konzervovaná sekvence MeSH
- kukla ultrastruktura MeSH
- larva ultrastruktura MeSH
- messenger RNA genetika metabolismus MeSH
- molekulární sekvence - údaje MeSH
- protein - isoformy chemie genetika metabolismus MeSH
- receptory buněčného povrchu genetika metabolismus MeSH
- RNA interference MeSH
- sekvence aminokyselin MeSH
- signální transdukce * MeSH
- Tribolium růst a vývoj ultrastruktura MeSH
- vývojová regulace genové exprese MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- hmyzí proteiny MeSH
- juvenilní hormony MeSH
- messenger RNA MeSH
- protein - isoformy MeSH
- receptory buněčného povrchu MeSH
Besides being a spectacular developmental process, metamorphosis is key to insect success. Entry into metamorphosis is controlled by juvenile hormone (JH). In larvae, JH prevents pupal and adult morphogenesis, thus keeping the insect in its immature state. How JH signals to preclude metamorphosis is poorly understood, and a JH receptor remains unknown. One candidate for the JH receptor role is the Methoprene-tolerant (Met) Per-Arnt-Sim (PAS) domain protein [also called Resistance to JH, Rst (1)JH], whose loss confers tolerance to JH and its mimic methoprene in the fruit fly Drosophila melanogaster. However, Met deficiency does not affect the larval-pupal transition, possibly because this process does not require JH absence in Drosophila. By contrast, the red flour beetle Tribolium castaneum is sensitive to developmental regulation by JH, thus making an ideal system to examine the role of Met in the antimetamorphic JH action. Here we show that impaired function of the Met ortholog TcMet renders Tribolium resistant to the effects of ectopic JH and, in a striking contrast to Drosophila, causes early-stage beetle larvae to undergo precocious metamorphosis. This is evident as TcMet-deficient larvae pupate prematurely or develop specific heterochronic phenotypes such as pupal-like cuticular structures, appendages, and compound eyes. Our results demonstrate that TcMet functions in JH response and provide the critical evidence that the putative JH receptor Met mediates the antimetamorphic effect of JH.
- MeSH
- biologická proměna genetika MeSH
- hmyzí geny * MeSH
- kukla účinky léků růst a vývoj ultrastruktura MeSH
- larva účinky léků růst a vývoj ultrastruktura MeSH
- messenger RNA analýza MeSH
- methopren farmakologie MeSH
- molekulární sekvence - údaje MeSH
- rezistence k insekticidům genetika MeSH
- RNA interference MeSH
- Tribolium genetika růst a vývoj MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- messenger RNA MeSH
- methopren MeSH
