Nutritional and toxicity profiles of two species of land snail, Theba pisana and Otala lactea, from Morocco

Mantle-collar tissue from adult land snails Otala lactea continuously incorporated labelled amino acids over a 72-h period of incubation in modified culture medium. Acid-saline extract of cerebral ganglia stimulated protein synthesis by the mantle-collar tissue in vitro. This effect was dose-dependent, with the minimum and maximum doses at 0.5 and 2 cerebral ganglion equivalents, respectively. The protein synthesis-stimulating factor(s) from the cerebral ganglia appeared to be proteinaceous and hydrophobic in nature. The cerebral ganglion extract was fractionated by means of a size-exclusion HPLC column. The biological activity was induced by three fractions with estimated molecular masses of 0.82, 1.88, and 4.33 kilodaltons (kDa). Porcine insulin antiserum abolished the activity of the 4.33- and 1.88-kDa fractions but had no significant effect on the activity of the 0.82-kDa fraction. The results suggest the existence in the cerebral ganglia of more than one factor with protein synthesis-stimulating activity. One of these factors could be related to mammalian insulin. Porcine insulin, however, had no significant effect on protein synthesis by the mantle collar in vitro.

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Pyruvate Kinase from the Land Snail Otala Lactea: Regulation by Reversible Phosphorylation During Estivation and Anoxia

Journal of Experimental Biology ◽

10.1242/jeb.154.1.321 ◽

1990 ◽

Vol 154 (1) ◽

pp. 321-337 ◽

Cited By ~ 2

Author(s):

ROSS E. WHITWAM ◽

KENNETH B. STOREY

Keyword(s):

Protein Kinase ◽

Pyruvate Kinase ◽

Time Course ◽

Land Snail ◽

Active Enzyme ◽

Kinetic Properties ◽

Reversible Phosphorylation ◽

Enzyme Form ◽

Otala Lactea ◽

Activity State

Pyruvate kinase (PK) from tissues of the desert snail Otala lactea (Müller) undergoes a stable modification of its kinetic properties during estivation or in response to anoxia stress. In foot muscle and mantle, the kinetic changes induced by either state were virtually identical and were consistent with a less active enzyme form in estivation or anoxia: S0.5 PEP increased, and I50 values for Mg-ATP and L-alanine decreased, compared to the enzyme in control (aroused) snails. Estivation and anoxia also changed the properties of PK from hepatopancreas; some changes were consistent with a more active enzyme form (So.5 PEP decreased, I50 values for Mg-ATP and L-alanine increased) but the enzyme lost all sensitivity to the potent activator fructose-l,6-bisphosphate. A time course of changes in I50 Mg-ATP for foot PK and S0.5 PEP for hepatopancreas PK revealed that estivation-induced changes in enzyme properties occurred between 12 and 48 h after snails were deprived of access to food and water, whereas the reversal of these changes occurred within as little as lOmin in foot muscle after arousal was initiated. The molecular basis of the stable modification of PK kinetics appears to be reversible protein phoshorylation. The action of added cyclic-AMP-dependent protein kinase on foot or hepatopancreas PK from control (aroused) snails changed PK kinetic parameters to those characteristic of the enzyme form in estivating animals; the addition of stimulators of endogenous cyclic-GMPdependent protein kinase or protein kinase C had the same effect. Conversely, treatment with added phosphatases reconverted the properties of foot muscle PK from estivating snails to those characteristic of the control enzyme. The data suggest that reversible phosphorylation control over the activity state of regulatory enzymes of glycolysis is one mechanism contributing to the overall metabolic rate depression of the estivating state.

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Insights into the ecotoxicological perturbations induced by the biocide abamectin in the white snail, Theba pisana

10.21203/rs.3.rs-995720/v1 ◽

2021 ◽

Author(s):

Mohamed Radwan ◽

Amira Gad

Keyword(s):

Biochemical Parameters ◽

Glycogen Content ◽

Land Snail ◽

Energy Reserves ◽

Glutathione S Transferase ◽

Total Proteins ◽

Time Intervals ◽

Theba Pisana ◽

Glutamyl Transferase ◽

Lethal Doses

Abstract Abamectin (avermectin B1, ABM) has been widely used as a biocide in agriculture, veterinary and medicine worldwide. In the current study, we aimed to evaluate the acute toxicity and sub-lethal biochemical responses of ABM on the non-target land snail, Theba pisana. Mortality of snails increased with the dose increase, resulting 48h- LD50 value of 1.048 µg/snail. Sub-lethal effects were studied on the survivors of 20% and 60% LD50 ABM doses and the biochemical parameters were assessed for up to 7 days of exposure. The results showed a decrease in glycogen content and lipids for two sub-lethal doses after all time intervals, whereas increased the level of total proteins after exposure to 60% LD50 ABM. Overall, the tested sub-lethal doses significantly decreased the total energy reserves. ABM-exposure to snails elevated γ-Glutamyl transferase (γ-GT) and Lactate dehydrogenase (LDH) activities at all-time intervals. A significant increase of Glutathione-S-transferase (GST) activity was also recorded in snails exposed to 20% and 60% LD50 after 7 days and all time intervals, respectively. However, ABM inhibited the activity of Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) after 7 days of exposure. Our investigation provides new insights into the disturbances of energy reserves and enzyme activities in T. pisana snails that can be used as useful sentinel organism. Indeed, these tested biochemical parameters of the snails are sensitive and may be used as biomarkers for assessing ABM toxicity.

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Localization and immunological characterization of insulin-like peptide(s) in the land snail Otala lactea (Mollusca: Pulmonata)

Canadian Journal of Zoology ◽

10.1139/cjz-78-9-1515 ◽

2000 ◽

Vol 78 (9) ◽

pp. 1515-1526

Author(s):

A.M. Abdraba ◽

A.S.M. Saleuddin

Keyword(s):

Land Snail ◽

Immunological Characterization ◽

Otala Lactea

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Role of ambient wavelength, shell size and pigmentation intensity in the heating of Mediterranean Theba pisana (Eupulmonata: Helicidae)

Journal of Molluscan Studies ◽

10.1093/mollus/eyaa006 ◽

2020 ◽

Vol 86 (3) ◽

pp. 249-253

Author(s):

Tatjana Tull ◽

Danina Schmidt ◽

Heinz-R Köhler

Keyword(s):

Biological Significance ◽

Green Light ◽

Land Snail ◽

Solar Irradiation ◽

Mediterranean Population ◽

Shell Size ◽

Light Emitting ◽

Theba Pisana ◽

Higher Temperature ◽

Set Up

ABSTRACT Theba pisana is a polymorphic land snail widely used in ecophysiological research on the biological significance of solar irradiation. We investigated whether, taking size into account, differently pigmented morphs of a Mediterranean population of T. pisana influence the snails’ heating under different wavelengths. We used a laboratory set-up comprising light-emitting diodes emitting visible light of defined wavelengths and quantified shell heating using high-resolution thermography. Shell pigmentation was quantified densitometrically. There were significant effects of both shell size and light wavelength, such that small snails heated more than large ones over 15 min, and blue light (470 nm) raised temperature more than green light (525 nm). Pigmentation alone did not show significance, but a trend towards higher temperature with increasing pigmentation was evident. Despite the observed significances and trends, we could only explain at most 4.67% of variation in shell heating by multiple regression modelling. However, the light intensity used in this experiment was low and the pigmentation intensity of the shells varied, at most, by a factor of 2. This suggests the actual temperature of a snail depends not only on the tested variables, but also on the multifactorial action of a number of unknown, perhaps intrinsic physiological parameters.

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Depression of Aerobic Metabolism and Intracellular pH by Hypercapnia in Land Snails, Otala Lactea

Journal of Experimental Biology ◽

10.1242/jeb.138.1.289 ◽

1988 ◽

Vol 138 (1) ◽

pp. 289-299 ◽

Cited By ~ 4

Author(s):

M. CHRISTOPHER BARNHART ◽

BRIAN R. McMAHON

Keyword(s):

Oxygen Consumption ◽

Intracellular Ph ◽

Respiratory Acidosis ◽

Land Snail ◽

Land Snails ◽

Whole Body ◽

Extracellular Acidosis ◽

Critical Po2 ◽

Otala Lactea ◽

La Jolla

The pulmonate land snail Otala lactea undergoes simultaneous hypercapnia, hypoxia, extracellular acidosis and metabolic depression during dormancy. We tested the effects of ambient hypercapnia and hypoxia on oxygen consumption (VO2) and on extracellular and intracellular pH of active (i.e. non-dormant) individuals. Active snails reduced VO2, by 50% within l h when exposed to 65mmHg (1 mmHg = 133.3Pa) ambient PCO2, and by 63% in 98mmHg. These levels of CO2 are within the range that occurs naturally in the lung and blood during dormancy. VO2 of hypercapnic snails remained below that of controls for the duration of exposure (up to 9 h) and returned to control levels within 1 h when CO2 was removed. Both pHe and whole-body pHi (measured using [14C]DMO) fell with increasing haemolymph PCO2 by approximately 0.7logPCO2 Critical (VO2- limiting) ambient PO2 of active snails was 90mmHg in the absence of CO2 and dropped to 50 mmHg when VO2 was reduced 45% by exposure to CO2. Estimated critical PO2 at the lower VO2 typical of dormancy is well below the typical lung PO2 of dormant Otala, suggesting that PO2 in the lung does not normally limit oxygen consumption during dormancy. These results support the hypothesis that hypercapnia or resulting respiratory acidosis depresses metabolic rate during dormancy, and argue against a limitation of VO2 by hypoxia. Note: Present address: Physiological Research Laboratory, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093, USA.

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