scholarly journals Sequencing and Gene Expression of HC‐9, an Aquaporin‐9 Homolog, in Freeze‐tolerant Cope's Gray Treefrog

2015 ◽  
Vol 29 (S1) ◽  
Author(s):  
Brian Stogsdill ◽  
Pon Ti Tsou ◽  
James Frisbie ◽  
David Goldstein
Keyword(s):  
Gene Expression ◽  
Aquaporin 9 ◽  
Freeze Tolerant ◽  
Gray Treefrog

scholarly journals Membrane trafficking of aquaglyceroporin HC‐3 in erythrocytes from the freeze tolerant anuran, Cope's gray treefrog, Hyla chrysoscelis

2013 ◽  
Vol 27 (S1) ◽  
Author(s):  
Elizabeth Claire Wetzel ◽  
Philip Nickell ◽  
Venkateshwar Mutyam ◽  
James Frisbie ◽  
David L Goldstein ◽  
...  
Keyword(s):  
Membrane Trafficking ◽  
Hyla Chrysoscelis ◽  
Freeze Tolerant ◽  
Gray Treefrog

Glucagon induces the gene expression of aquaporin-8 but not that of aquaporin-9 water channels in the rat hepatocyte

2009 ◽  
Vol 296 (4) ◽  
pp. R1274-R1281 ◽  
Author(s):  
Leandro R. Soria ◽  
Sergio A. Gradilone ◽  
M. Cecilia Larocca ◽  
Raúl A. Marinelli
Keyword(s):  
Gene Expression ◽  
Rna Polymerase Ii ◽  
Rat Hepatocytes ◽  
Water Channels ◽  
Bile Secretion ◽  
Signal Pathways ◽  
Rat Hepatocyte ◽  
Confocal Immunofluorescence Microscopy ◽  
Aquaporin 9 ◽  
Additional Support

Glucagon stimulates the vesicle trafficking of aquaporin-8 (AQP8) water channels to the rat hepatocyte canalicular membranes, a process thought to be relevant to glucagon-induced bile secretion. In this study, we investigated whether glucagon is able to modulate the gene expression of hepatocyte AQP8. Glucagon was administered to rats at 0.2 mg/100 g body wt ip in 2, 3, or 6 equally spaced doses for 8, 16, and 36 h, respectively. Immunoblotting analysis showed that hepatic 34-kDa AQP8 was significantly increased by 79 and 107% at 16 and 36 h, respectively. Hepatic AQP9 protein expression remained unaltered. AQP8 mRNA expression, assessed by real-time PCR, was not modified over time, suggesting a posttranscriptional mechanism of AQP8 protein increase. Glucagon effects on AQP8 were directly studied in primary cultured rat hepatocytes. Immunoblotting and confocal immunofluorescence microscopy confirmed the specific glucagon-induced AQP8 upregulation. The RNA polymerase II inhibitor actinomycin D was unable to prevent glucagon effect, providing additional support to the nontranscriptional upregulation of AQP8. Cycloheximide also showed no effect, suggesting that glucagon-induced AQP8 expression does not depend on protein synthesis but rather on protein degradation. Inhibitory experiments suggest that a reduced calpain-mediated AQP8 proteolysis could be involved. The action of glucagon on hepatocyte AQP8 was mimicked by dibutyryl cAMP and suppressed by PKA or phosphatidylinositol-3-kinase (PI3K) inhibitors. In conclusion, our data suggest that glucagon induces the gene expression of rat hepatocyte AQP8 by reducing its degradation, a process that involves cAMP-PKA and PI3K signal pathways.

scholarly journals Changes in Energy Reserves and Gene Expression Elicited by Freezing and Supercooling in the Antarctic Midge, Belgica antarctica

Insects ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 18 ◽  
Author(s):  
Nicholas M. Teets ◽  
Emma G. Dalrymple ◽  
Maya H. Hillis ◽  
J. D. Gantz ◽  
Drew E. Spacht ◽  
...  
Keyword(s):  
Gene Expression ◽  
Tissue Damage ◽  
Recovery Period ◽  
Freeze Tolerance ◽  
Energetic Costs ◽  
Belgica Antarctica ◽  
Freeze Tolerant ◽  
Glycogen Stores ◽  
The Antarctic ◽  
Stress Gene

Freeze-tolerance, or the ability to survive internal ice formation, is relatively rare among insects. Larvae of the Antarctic midge Belgica antarctica are freeze-tolerant year-round, but in dry environments, the larvae can remain supercooled (i.e., unfrozen) at subzero temperatures. In previous work with summer-acclimatized larvae, we showed that freezing is considerably more stressful than remaining supercooled. Here, these findings are extended by comparing survival, tissue damage, energetic costs, and stress gene expression in larvae that have undergone an artificial winter acclimation regime and are either frozen or supercooled at −5 °C. In contrast to summer larvae, winter larvae survive at −5 °C equally well for up to 14 days, whether frozen or supercooled, and there is no tissue damage at these conditions. In subsequent experiments, we measured energy stores and stress gene expression following cold exposure at −5 °C for either 24 h or 14 days, with and without a 12 h recovery period. We observed slight energetic costs to freezing, as frozen larvae tended to have lower glycogen stores across all groups. In addition, the abundance of two heat shock protein transcripts, hsp60 and hsp90, tended to be higher in frozen larvae, indicating higher levels of protein damage following freezing. Together, these results indicate a slight cost to being frozen relative to remaining supercooled, which may have implications for the selection of hibernacula and responses to climate change.

scholarly journals Hepatic transcriptome of the freeze-tolerant Cope’s gray treefrog, Dryophytes chrysoscelis: responses to cold acclimation and freezing

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
M. Clara F. do Amaral ◽  
James Frisbie ◽  
Raphael J. Crum ◽  
David L. Goldstein ◽  
Carissa M. Krane
Keyword(s):  
Cold Acclimation ◽  
Freeze Tolerant ◽  
Gray Treefrog ◽  
Hepatic Transcriptome

scholarly journals Temperature‐Induced Changes to Aquaporin Localization in the Freeze‐Tolerant Cope's Gray Treefrog

2017 ◽  
Vol 31 (S1) ◽  
Author(s):  
Brian Stogsdill ◽  
James Frisbie ◽  
Carissa Krane ◽  
David Goldstein
Keyword(s):  
Freeze Tolerant ◽  
Induced Changes ◽  
Gray Treefrog
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