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Light and pheromone-sensing neurons regulates cold habituation through insulin signalling in Caenorhabditis elegans.

Ohta A, Ujisawa T, Sonoda S, Kuhara A - Nat Commun (2014)

Bottom Line: However, how animals habituate to temperature is poorly understood.Calcium imaging reveals that ASJ neurons respond to temperature.Thus, temperature sensation in a light and pheromone-sensing neuron produces a robust effect on insulin signalling that controls experience-dependent temperature habituation.

View Article: PubMed Central - PubMed

Affiliation: 1] Laboratory of Molecular and Cellular Regulation, Faculty of Science and Engineering, Institute for Integrative Neurobiology, Konan University, 8-9-1 Okamoto, Higashinada-ku, Kobe 658-8501, Japan [2].

ABSTRACT
Temperature is a critical environmental stimulus that has a strong impact on an organism's biochemistry. Animals can respond to changes in ambient temperature through behaviour or altered physiology. However, how animals habituate to temperature is poorly understood. The nematode C. elegans stores temperature experiences and can induce temperature habituation-linked cold tolerance. Here we show that light and pheromone-sensing neurons (ASJ) regulate cold habituation through insulin signalling. Calcium imaging reveals that ASJ neurons respond to temperature. Cold habituation is abnormal in a mutant with impaired cGMP signalling in ASJ neurons. Insulin released from ASJ neurons is received by the intestine and neurons regulating gene expression for cold habituation. Thus, temperature sensation in a light and pheromone-sensing neuron produces a robust effect on insulin signalling that controls experience-dependent temperature habituation.

No MeSH data available.


Related in: MedlinePlus

Insulin signalling is involved in cold tolerance.(a) Cold tolerance of mutants with impaired synaptic transmission containing carboxypeptidase (egl-21), synaptotagmin (snt-1), synaptobrevin (snb-1) and syntaxin (unc-64). These mutants showed abnormal increments in cold tolerance. For each assay, n≥6. (b) A model of insulin signalling in dauer formation based on previous reports232427. ins-1, ins-6 and daf-28 encode insulin. daf-2 encodes the insulin receptor only in C. elegans. age-1 and pdk-1 encode phosphoinositide 3-kinase and 3-phosphoinositide dependent kinase, respectively. akt-1 and akt-2 encode serine/threonine kinase. daf-16 encodes FOXO transcription factor. Downstream cascade of DAF-2/insulin receptor contains AGE-1, PDK-1, AKT-1 and AKT-2. AKT-1 and AKT-2 inhibit nuclear translocation of DAF-16. Therefore, DAF-2 signalling negatively regulates DAF-16 in dauer formation. (c) Cold tolerance of mutants defective in insulin signalling. Animals of all strains were cultivated at 15 °C from egg to L4 larvae, and after that, animals were cultivated at 20 °C overnight from L4 to adult, because many insulin-signalling mutants showed constitutive dauer formation (daf-c) at 20 °C. Wild type; Is[daf-16] is an N2 strain with an integrated form of DAF-16::GFP, which also shows daf-c46. For each assay, n≥9. (d) Cell-specific rescue experiments of daf-28  mutants. Cell-specific promoters used in this experiment were trx-1, str-3 or ceh-36 promoters for expression in ASJ, ASI or AWC cells, respectively. ges-1p::NLS-GFP was co-injected as a transgenic marker in all transgenic strains. For each assay, n≥9. (e) Localization of DAF-28 at the synapse of ASJ. Wild type with ASJ-specific expression of DAF-28::dsRedm and SNB-1::VENUS (wild type; Ex[trx-1p::daf-28::dsRedm, trx-1p::snb-1::VENUS]) were analyzed by confocal microscopy. The upper-left panel indicates a schematic diagram of synapses in ASJ of head. In the upper-right panel, arrows indicate localization of synaptobrevin (SNB-1)::VENUS at synapses in ASJ. In the bottom-left panel, arrows indicate localization of DAF-28::dsRedm in ASJ. The bottom-right panel is the merged image of upper-right panel, bottom-left panel and bright-field image. In the merged image, arrows indicate white regions that suggest co-localization of SNB-1::VENUS and DAF-28::DsRedm at synapses. Scale bar, 10 μm. Error bars indicate standard error of the mean. Analysis of variance followed by Dunnet post-hoc test was used for multiple comparisons. *P<0.05; **P<0.01.
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f5: Insulin signalling is involved in cold tolerance.(a) Cold tolerance of mutants with impaired synaptic transmission containing carboxypeptidase (egl-21), synaptotagmin (snt-1), synaptobrevin (snb-1) and syntaxin (unc-64). These mutants showed abnormal increments in cold tolerance. For each assay, n≥6. (b) A model of insulin signalling in dauer formation based on previous reports232427. ins-1, ins-6 and daf-28 encode insulin. daf-2 encodes the insulin receptor only in C. elegans. age-1 and pdk-1 encode phosphoinositide 3-kinase and 3-phosphoinositide dependent kinase, respectively. akt-1 and akt-2 encode serine/threonine kinase. daf-16 encodes FOXO transcription factor. Downstream cascade of DAF-2/insulin receptor contains AGE-1, PDK-1, AKT-1 and AKT-2. AKT-1 and AKT-2 inhibit nuclear translocation of DAF-16. Therefore, DAF-2 signalling negatively regulates DAF-16 in dauer formation. (c) Cold tolerance of mutants defective in insulin signalling. Animals of all strains were cultivated at 15 °C from egg to L4 larvae, and after that, animals were cultivated at 20 °C overnight from L4 to adult, because many insulin-signalling mutants showed constitutive dauer formation (daf-c) at 20 °C. Wild type; Is[daf-16] is an N2 strain with an integrated form of DAF-16::GFP, which also shows daf-c46. For each assay, n≥9. (d) Cell-specific rescue experiments of daf-28 mutants. Cell-specific promoters used in this experiment were trx-1, str-3 or ceh-36 promoters for expression in ASJ, ASI or AWC cells, respectively. ges-1p::NLS-GFP was co-injected as a transgenic marker in all transgenic strains. For each assay, n≥9. (e) Localization of DAF-28 at the synapse of ASJ. Wild type with ASJ-specific expression of DAF-28::dsRedm and SNB-1::VENUS (wild type; Ex[trx-1p::daf-28::dsRedm, trx-1p::snb-1::VENUS]) were analyzed by confocal microscopy. The upper-left panel indicates a schematic diagram of synapses in ASJ of head. In the upper-right panel, arrows indicate localization of synaptobrevin (SNB-1)::VENUS at synapses in ASJ. In the bottom-left panel, arrows indicate localization of DAF-28::dsRedm in ASJ. The bottom-right panel is the merged image of upper-right panel, bottom-left panel and bright-field image. In the merged image, arrows indicate white regions that suggest co-localization of SNB-1::VENUS and DAF-28::DsRedm at synapses. Scale bar, 10 μm. Error bars indicate standard error of the mean. Analysis of variance followed by Dunnet post-hoc test was used for multiple comparisons. *P<0.05; **P<0.01.

Mentions: We next investigated how ASJ sensory neurons control temperature experience-dependent cold tolerance. We demonstrated that mutants defective in synaptic transmission, including mutants of SNB-1/Synaptobrevin, SNT-1/Synaptotagmin, UNC-64/Syntaxin or EGL-21/Neuropeptide processing enzyme, showed abnormal enhancement of cold tolerance phenotypes that were similar to those of ASJ-defective mutants (Fig. 5a). These results imply that neurotransmission is important for cold tolerance.


Light and pheromone-sensing neurons regulates cold habituation through insulin signalling in Caenorhabditis elegans.

Ohta A, Ujisawa T, Sonoda S, Kuhara A - Nat Commun (2014)

Insulin signalling is involved in cold tolerance.(a) Cold tolerance of mutants with impaired synaptic transmission containing carboxypeptidase (egl-21), synaptotagmin (snt-1), synaptobrevin (snb-1) and syntaxin (unc-64). These mutants showed abnormal increments in cold tolerance. For each assay, n≥6. (b) A model of insulin signalling in dauer formation based on previous reports232427. ins-1, ins-6 and daf-28 encode insulin. daf-2 encodes the insulin receptor only in C. elegans. age-1 and pdk-1 encode phosphoinositide 3-kinase and 3-phosphoinositide dependent kinase, respectively. akt-1 and akt-2 encode serine/threonine kinase. daf-16 encodes FOXO transcription factor. Downstream cascade of DAF-2/insulin receptor contains AGE-1, PDK-1, AKT-1 and AKT-2. AKT-1 and AKT-2 inhibit nuclear translocation of DAF-16. Therefore, DAF-2 signalling negatively regulates DAF-16 in dauer formation. (c) Cold tolerance of mutants defective in insulin signalling. Animals of all strains were cultivated at 15 °C from egg to L4 larvae, and after that, animals were cultivated at 20 °C overnight from L4 to adult, because many insulin-signalling mutants showed constitutive dauer formation (daf-c) at 20 °C. Wild type; Is[daf-16] is an N2 strain with an integrated form of DAF-16::GFP, which also shows daf-c46. For each assay, n≥9. (d) Cell-specific rescue experiments of daf-28  mutants. Cell-specific promoters used in this experiment were trx-1, str-3 or ceh-36 promoters for expression in ASJ, ASI or AWC cells, respectively. ges-1p::NLS-GFP was co-injected as a transgenic marker in all transgenic strains. For each assay, n≥9. (e) Localization of DAF-28 at the synapse of ASJ. Wild type with ASJ-specific expression of DAF-28::dsRedm and SNB-1::VENUS (wild type; Ex[trx-1p::daf-28::dsRedm, trx-1p::snb-1::VENUS]) were analyzed by confocal microscopy. The upper-left panel indicates a schematic diagram of synapses in ASJ of head. In the upper-right panel, arrows indicate localization of synaptobrevin (SNB-1)::VENUS at synapses in ASJ. In the bottom-left panel, arrows indicate localization of DAF-28::dsRedm in ASJ. The bottom-right panel is the merged image of upper-right panel, bottom-left panel and bright-field image. In the merged image, arrows indicate white regions that suggest co-localization of SNB-1::VENUS and DAF-28::DsRedm at synapses. Scale bar, 10 μm. Error bars indicate standard error of the mean. Analysis of variance followed by Dunnet post-hoc test was used for multiple comparisons. *P<0.05; **P<0.01.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4109018&req=5

f5: Insulin signalling is involved in cold tolerance.(a) Cold tolerance of mutants with impaired synaptic transmission containing carboxypeptidase (egl-21), synaptotagmin (snt-1), synaptobrevin (snb-1) and syntaxin (unc-64). These mutants showed abnormal increments in cold tolerance. For each assay, n≥6. (b) A model of insulin signalling in dauer formation based on previous reports232427. ins-1, ins-6 and daf-28 encode insulin. daf-2 encodes the insulin receptor only in C. elegans. age-1 and pdk-1 encode phosphoinositide 3-kinase and 3-phosphoinositide dependent kinase, respectively. akt-1 and akt-2 encode serine/threonine kinase. daf-16 encodes FOXO transcription factor. Downstream cascade of DAF-2/insulin receptor contains AGE-1, PDK-1, AKT-1 and AKT-2. AKT-1 and AKT-2 inhibit nuclear translocation of DAF-16. Therefore, DAF-2 signalling negatively regulates DAF-16 in dauer formation. (c) Cold tolerance of mutants defective in insulin signalling. Animals of all strains were cultivated at 15 °C from egg to L4 larvae, and after that, animals were cultivated at 20 °C overnight from L4 to adult, because many insulin-signalling mutants showed constitutive dauer formation (daf-c) at 20 °C. Wild type; Is[daf-16] is an N2 strain with an integrated form of DAF-16::GFP, which also shows daf-c46. For each assay, n≥9. (d) Cell-specific rescue experiments of daf-28 mutants. Cell-specific promoters used in this experiment were trx-1, str-3 or ceh-36 promoters for expression in ASJ, ASI or AWC cells, respectively. ges-1p::NLS-GFP was co-injected as a transgenic marker in all transgenic strains. For each assay, n≥9. (e) Localization of DAF-28 at the synapse of ASJ. Wild type with ASJ-specific expression of DAF-28::dsRedm and SNB-1::VENUS (wild type; Ex[trx-1p::daf-28::dsRedm, trx-1p::snb-1::VENUS]) were analyzed by confocal microscopy. The upper-left panel indicates a schematic diagram of synapses in ASJ of head. In the upper-right panel, arrows indicate localization of synaptobrevin (SNB-1)::VENUS at synapses in ASJ. In the bottom-left panel, arrows indicate localization of DAF-28::dsRedm in ASJ. The bottom-right panel is the merged image of upper-right panel, bottom-left panel and bright-field image. In the merged image, arrows indicate white regions that suggest co-localization of SNB-1::VENUS and DAF-28::DsRedm at synapses. Scale bar, 10 μm. Error bars indicate standard error of the mean. Analysis of variance followed by Dunnet post-hoc test was used for multiple comparisons. *P<0.05; **P<0.01.
Mentions: We next investigated how ASJ sensory neurons control temperature experience-dependent cold tolerance. We demonstrated that mutants defective in synaptic transmission, including mutants of SNB-1/Synaptobrevin, SNT-1/Synaptotagmin, UNC-64/Syntaxin or EGL-21/Neuropeptide processing enzyme, showed abnormal enhancement of cold tolerance phenotypes that were similar to those of ASJ-defective mutants (Fig. 5a). These results imply that neurotransmission is important for cold tolerance.

Bottom Line: However, how animals habituate to temperature is poorly understood.Calcium imaging reveals that ASJ neurons respond to temperature.Thus, temperature sensation in a light and pheromone-sensing neuron produces a robust effect on insulin signalling that controls experience-dependent temperature habituation.

View Article: PubMed Central - PubMed

Affiliation: 1] Laboratory of Molecular and Cellular Regulation, Faculty of Science and Engineering, Institute for Integrative Neurobiology, Konan University, 8-9-1 Okamoto, Higashinada-ku, Kobe 658-8501, Japan [2].

ABSTRACT
Temperature is a critical environmental stimulus that has a strong impact on an organism's biochemistry. Animals can respond to changes in ambient temperature through behaviour or altered physiology. However, how animals habituate to temperature is poorly understood. The nematode C. elegans stores temperature experiences and can induce temperature habituation-linked cold tolerance. Here we show that light and pheromone-sensing neurons (ASJ) regulate cold habituation through insulin signalling. Calcium imaging reveals that ASJ neurons respond to temperature. Cold habituation is abnormal in a mutant with impaired cGMP signalling in ASJ neurons. Insulin released from ASJ neurons is received by the intestine and neurons regulating gene expression for cold habituation. Thus, temperature sensation in a light and pheromone-sensing neuron produces a robust effect on insulin signalling that controls experience-dependent temperature habituation.

No MeSH data available.


Related in: MedlinePlus