Expression patterns of two carbonic anhydrase genes, Na+/K+-ATPase and V-type H+-ATPase, in the freshwater crayfish, Cherax quadricarinatus, exposed to low pH and high pH

2017 ◽  
Vol 65 (1) ◽  
pp. 50 ◽  
Author(s):  
Muhammad Yousuf Ali ◽  
Ana Pavasovic ◽  
Peter B. Mather ◽  
Peter J. Prentis
Keyword(s):  
Carbonic Anhydrase ◽  
Expression Patterns ◽  
Maximum Level ◽  
Low Ph ◽  
Freshwater Crayfish ◽  
Α Subunit ◽  
Cherax Quadricarinatus ◽  
High Ph ◽  
Internal Ph ◽  
Ph Conditions

Carbonic anhydrase (CA), Na+/K+-ATPase (NKA) and Vacuolar-type H+-ATPase (HAT) play vital roles in osmoregulation and pH balance in decapod crustaceans. As variable pH levels have a significant impact on the physiology of crustaceans, it is crucial to understand the mechanisms by which an animal maintains its internal pH. We examined expression patterns of cytoplasmic (CAc) and membrane-associated form (CAg) of CA, NKA α subunit and HAT subunit a in gills of freshwater crayfish, Cherax quadricarinatus, at three pH levels – 6.2, 7.2 (control) and 8.2 – over 24 h. Expression levels of CAc were significantly increased at low pH and decreased at high pH conditions 24 h after transfer. Expression increased at low pH after 12 h, and reached its maximum level by 24 h. CAg showed a significant increase in expression at 6 h after transfer at low pH. Expression of NKA significantly increased at 6 h after transfer to pH 6.2 and remained elevated for up to 24 h. Expression for HAT and NKA showed similar patterns, where expression significantly increased 6 h after transfer to low pH and remained significantly elevated throughout the experiment. Overall, CAc, CAg, NKA and HAT gene expression is induced at low pH conditions in freshwater crayfish.

scholarly journals Expression patterns of two Carbonic anhydrase genes, Na+/K+-ATPase and V-type H+-ATPase in the freshwater crayfish, Cherax quadricarinatus, under different pH

2015 ◽  
Author(s):  
Muhammad Yousuf Ali ◽  
Ana Pavasovic ◽  
Peter B Mather ◽  
Peter J Prentis
Keyword(s):  
Carbonic Anhydrase ◽  
Expression Patterns ◽  
Low Ph ◽  
Freshwater Crayfish ◽  
Acid Base Balance ◽  
Acid Base ◽  
Expression Levels ◽  
High Ph ◽  
Base Balance ◽  
Ph Conditions

Osmoregulation and systemic acid-base balance in decapod crustaceans are largely controlled by a set of transport-related enzymes including carbonic anhydrase (CA), Na + /K + -ATPase (NKA) and V-type- H + -ATPase (HAT). Variable pH levels and changes in osmotic pressure can have a significant impact on the physiology and behaviour of crustaceans. Therefore, it is crucial to understand the mechanisms via which an animal can maintain its internal pH balance and regulate the movement of ions into and out of its cells. Here, we examined expression patterns of the cytoplasmic (CAc) and membrane-associated form (CAg) of CA, NKA α subunit and HAT subunit a in gills of the freshwater crayfish Cherax quadricarinatus. Expression levels of the genes were measured at three pH levels, pH 6.2, 7.2 (control) and 8.2 over a 24 hour period. All genes showed significant differences in expression levels, either among pH treatments or over time. Expression levels of CAc were significantly increased at low pH and decreased at high pH conditions 24 h after transfer to these treatments. Expression increased in low pH after 12 h, and reached their maximum level by 24 h. The membrane-associated form CAg showed changes in expression levels more quickly than CAc. Expression increased for CAg at 6 h post transfer at both low and high pH conditions, but expression remained elevated only at low pH (6.2) at the end of the experiment. Expression of CqNKA significantly increased at 6 h after transfer to pH 6.2 and remained elevated up to 24 h. Expression for HAT and NKA showed similar patterns, where expression significantly increased 6 h post transfer to the low pH conditions and remained significantly elevated throughout the experiment. The only difference in expression between the two genes was that HAT expression decreased significantly 24 h post transfer to high pH conditions. Overall, our data suggest that CAc, CAg, NKA and HAT gene expression is induced at low pH conditions in freshwater crayfish. Further research should examine the physiological underpinnings of these changes in expression to better understand systemic acid/base balance in freshwater crayfish.

scholarly journals Expression patterns of two Carbonic anhydrase genes, Na+/K+-ATPase and V-type H+-ATPase in the freshwater crayfish, Cherax quadricarinatus, under different pH

2015 ◽  
Author(s):  
Muhammad Yousuf Ali ◽  
Ana Pavasovic ◽  
Peter B Mather ◽  
Peter J Prentis
Keyword(s):  
Carbonic Anhydrase ◽  
Expression Patterns ◽  
Low Ph ◽  
Freshwater Crayfish ◽  
Acid Base Balance ◽  
Acid Base ◽  
Expression Levels ◽  
High Ph ◽  
Base Balance ◽  
Ph Conditions

Osmoregulation and systemic acid-base balance in decapod crustaceans are largely controlled by a set of transport-related enzymes including carbonic anhydrase (CA), Na + /K + -ATPase (NKA) and V-type- H + -ATPase (HAT). Variable pH levels and changes in osmotic pressure can have a significant impact on the physiology and behaviour of crustaceans. Therefore, it is crucial to understand the mechanisms via which an animal can maintain its internal pH balance and regulate the movement of ions into and out of its cells. Here, we examined expression patterns of the cytoplasmic (CAc) and membrane-associated form (CAg) of CA, NKA α subunit and HAT subunit a in gills of the freshwater crayfish Cherax quadricarinatus. Expression levels of the genes were measured at three pH levels, pH 6.2, 7.2 (control) and 8.2 over a 24 hour period. All genes showed significant differences in expression levels, either among pH treatments or over time. Expression levels of CAc were significantly increased at low pH and decreased at high pH conditions 24 h after transfer to these treatments. Expression increased in low pH after 12 h, and reached their maximum level by 24 h. The membrane-associated form CAg showed changes in expression levels more quickly than CAc. Expression increased for CAg at 6 h post transfer at both low and high pH conditions, but expression remained elevated only at low pH (6.2) at the end of the experiment. Expression of CqNKA significantly increased at 6 h after transfer to pH 6.2 and remained elevated up to 24 h. Expression for HAT and NKA showed similar patterns, where expression significantly increased 6 h post transfer to the low pH conditions and remained significantly elevated throughout the experiment. The only difference in expression between the two genes was that HAT expression decreased significantly 24 h post transfer to high pH conditions. Overall, our data suggest that CAc, CAg, NKA and HAT gene expression is induced at low pH conditions in freshwater crayfish. Further research should examine the physiological underpinnings of these changes in expression to better understand systemic acid/base balance in freshwater crayfish.

Hydrothermal crystallization kinetics of m-ZrO2 and t-ZrO2

1990 ◽  
Vol 5 (11) ◽  
pp. 2698-2705 ◽  
Author(s):  
Raymond P. Denkewicz ◽  
Kevor S. TenHuisen ◽  
James H. Adair
Keyword(s):  
Crystallization Kinetics ◽  
Low Ph ◽  
Formation Mechanisms ◽  
Gel Structure ◽  
Hydrothermal Conditions ◽  
High Ph ◽  
Ph Values ◽  
Ph Conditions ◽  
Apparent Activation Energies ◽  
Kinetics Of

The isothermal nucleation and crystallization kinetics of hydrothermally prepared monoclinic and tetragonal ZrO2 have been determined at various pH conditions. It is shown that monoclinic ZrO2 precipitates at low pH whereas at high pH tetragonal ZrO2 crystallizes from an amorphous zirconium (hydrous) oxide, Zr(OH)xOy, precursor. At intermediate pH conditions mixtures of the polymorphs are formed suggestive of kinetically competing particle formation mechanisms. The data are explained by the proposed existence of three controlling regimes for the formation of crystalline ZrO2: dissolution/precipitation at low pH, a solubility controlled regime at intermediate pH values, and a gel structure controlled regime at high pH. Apparent activation energies for the nucleation and crystallization of monoclinic and tetragonal ZrO2 formed under hydrothermal conditions are presented.

Analysis, characterisation and expression of gill-expressed carbonic anhydrase genes in the freshwater crayfish Cherax quadricarinatus

Gene ◽  
2015 ◽  
Vol 564 (2) ◽  
pp. 176-187 ◽  
Author(s):  
Muhammad Yousuf Ali ◽  
Ana Pavasovic ◽  
Peter B. Mather ◽  
Peter J. Prentis
Keyword(s):  
Carbonic Anhydrase ◽  
Freshwater Crayfish ◽  
Cherax Quadricarinatus

scholarly journals Distinct Expression Patterns of Carbonic Anhydrase IX in Clear Cell, Microcystic, and Angiomatous Meningiomas

2019 ◽  
Vol 78 (12) ◽  
pp. 1081-1088
Author(s):  
Rati Chkheidze ◽  
Patrick J Cimino ◽  
Kimmo J Hatanpaa ◽  
Charles L White ◽  
Manuel Ferreira ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Clear Cell ◽  
Expression Patterns ◽  
Carbonic Anhydrase Ix ◽  
World Health ◽  
Loss Of Function ◽  
Ca Ix ◽  
Hypoxia Marker ◽  
Other World ◽  
Health Organization

Abstract Clear cell, microcytic, and angiomatous meningiomas are 3 vasculature-rich variants with overlapping morphological features but different prognostic and treatment implications. Distinction between them is not always straightforward. We compared the expression patterns of the hypoxia marker carbonic anhydrase IX (CA-IX) in meningiomas with predominant clear cell (n = 15), microcystic (n = 9), or angiomatous (n = 11) morphologies, as well as 117 cases of other World Health Organization recognized histological meningioma variants. Immunostaining for SMARCE1 protein, whose loss-of-function has been associated with clear cell meningiomas, was performed on all clear cell meningiomas, and selected variants of meningiomas as controls. All clear cell meningiomas showed absence of CA-IX expression and loss of nuclear SMARCE1 expression. All microcystic and angiomatous meningiomas showed diffuse CA-IX immunoreactivity and retained nuclear SMARCE1 expression. In other meningioma variants, CA-IX was expressed in a hypoxia-restricted pattern and was highly associated with atypical features such as necrosis, small cell change, and focal clear cell change. In conclusion, CA-IX may serve as a useful diagnostic marker in differentiating clear cell, microcystic, and angiomatous meningiomas.

Regulation of ion transport by pH and [HCO3−] in isolated gills of the crab Neohelice (Chasmagnathus) granulata

2008 ◽  
Vol 294 (3) ◽  
pp. R1033-R1043 ◽  
Author(s):  
Martin Tresguerres ◽  
Scott K. Parks ◽  
Sebastian E. Sabatini ◽  
Greg G. Goss ◽  
Carlos M. Luquet
Keyword(s):  
Carbonic Anhydrase ◽  
Ion Transport ◽  
Acid Secretion ◽  
Cellular Response ◽  
Low Ph ◽  
Potential Difference ◽  
Anion Exchangers ◽  
Transepithelial Potential Difference ◽  
Chasmagnathus Granulata ◽  
First Time

Posterior isolated gills of Neohelice ( Chasmagnathus) granulatus were symmetrically perfused with hemolymph-like saline of varying [HCO3−] and pH. Elevating [HCO3−] in the saline from 2.5 to 12.5 mmol/l (pH 7.75 in both cases) induced a significant increase in the transepithelial potential difference ( Vte), a measure of ion transport. The elevation in [HCO3−] also induced a switch from acid secretion (−43.7 ± 22.5 μequiv·kg−1·h−1) in controls to base secretion (84.7 ± 14.4 μequiv·kg−1·h−1). The HCO3−-induced Vte increase was inhibited by basolateral acetazolamide (200 μmol/l), amiloride (1 mmol/l), and ouabain (5 mmol/l) but not by bafilomycin (100 nmol/l). The Vte response to HCO3− did not take place in Cl−-free conditions; however, it was unaffected by apical SITS (2 mmol/l) or DIDS (1 mmol/l). A decrease in pH from 7.75 to 7.45 pH units in the perfusate also induced a significant increase in Vte, which was matched by a net increase in acid secretion of 67.8 ± 18.4 μequiv kg−1 h−1. This stimulation was sensitive to basolateral acetazolamide, bafilomycin, DIDS, and Na+-free conditions, but it still took place in Cl−-free saline. Therefore, the cellular response to low pH is different from the HCO3−-stimulated response. We also report V-H+-ATPase- and Na+-K+-ATPase-like immunoreactivity in gill sections for the first time in this crab. Our results suggest that carbonic anhydrase (CA), basolateral Na+/H+ exchangers and Na+-K+-ATPase and apical anion exchangers participate in the HCO3−-stimulated response, while CA, apical V-H+-ATPase and basolateral HCO3−-dependent cotransporters mediate the response to low pH.

scholarly journals A method for the preparation of low-pH dodecyl sulphate/polyacrylamide-gradient gels

1981 ◽  
Vol 193 (3) ◽  
pp. 1013-1015 ◽  
Author(s):  
G D Jones ◽  
M T Wilson ◽  
V M Darley-Usmar
Keyword(s):  
Cytochrome Oxidase ◽  
Low Ph ◽  
High Ph ◽  
Gel System

1. A low-pH lithium dodecyl sulphate/polyacrylamide-gradient slab-gel system, suitable for electrophoresis, is described, and the migration properties of standard proteins are compared on this and conventional high-pH gels. 2. Cytochrome oxidase may be partially resolved into its component polypeptides. The order of migration of these is, however, dependent on the pH of the gel system.

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