Histochemical Detection of Mannitol Oxidase in the Digestive Gland of Gastropods

Some diatom species of the genus Pseudo-nitzschia produce the toxin domoic acid. The depuration rate of domoic acid in Pecten maximus is very low; for this reason, king scallops generally contain high levels of domoic acid in their tissues. A transcriptomic approach was used to identify the genes differentially expressed in the P. maximus digestive gland after the injection of domoic acid. The differential expression analysis found 535 differentially expressed genes (226 up-regulated and 309 down-regulated). Protein–protein interaction networks obtained with the up-regulated genes were enriched in gene ontology terms, such as vesicle-mediated transport, response to stress, signal transduction, immune system process, RNA metabolic process, and autophagy, while networks obtained with the down-regulated genes were enriched in gene ontology terms, such as response to stress, immune system process, ribosome biogenesis, signal transduction, and mRNA processing. Genes that code for cytochrome P450 enzymes, glutathione S-transferase theta-1, glutamine synthase, pyrroline-5-carboxylate reductase 2, and sodium- and chloride-dependent glycine transporter 1 were among the up-regulated genes. Therefore, a stress response at the level of gene expression, that could be caused by the domoic acid injection, was evidenced by the alteration of several biological, cellular, and molecular processes.

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Characterization of the Domoic Acid Uptake Mechanism of the Mussel (Mytilus galloprovincialis) Digestive Gland

Toxins ◽

10.3390/toxins13070458 ◽

2021 ◽

Vol 13 (7) ◽

pp. 458

Author(s):

Juan Blanco ◽

Carmen Mariño ◽

Helena Martín ◽

Gonzalo Álvarez ◽

Araceli E. Rossignoli

Keyword(s):

Digestive Gland ◽

Domoic Acid ◽

Mytilus Galloprovincialis ◽

Metabolic Inhibitor ◽

Acid Uptake ◽

Free Medium ◽

Shellfish Poisoning ◽

Uptake Mechanism ◽

Amnesic Shellfish Poisoning

Cultures of the mussel Mytilus galloprovincialis are frequently affected by accumulation of the amnesic shellfish poisoning toxin domoic acid (DA). This species is characterized by a fast uptake and release of the toxin. In this work, the main characteristics of the uptake mechanism have been studied by incubation of digestive gland thin slices in media with different composition and DA concentration. DA uptake seems to follow Michaelis–Menten kinetics, with a very high estimated KM (1722 µg DA mL−1) and a Vmax of 71.9 µg DA g−1 h−1, which is similar to those found for other amino acids in invertebrates. Replacement of NaCl from the incubation media by Cl-choline (Na+-free medium) did not significantly reduce the uptake, but replacement by sorbitol (Na+-free and Cl−-depleted medium) did. A new experiment replacing all chlorides with their equivalent gluconates (Na+- and Cl−-free medium) showed an important reduction in the uptake that should be attributed to the absence of chloride, pointing to a Na+-independent, Cl− (or anion-) dependent transporter. In media with Na+ and Cl−, neither decreasing the pH nor adding cyanide (a metabolic inhibitor) had significant effect on DA uptake, suggesting that the transport mechanism is not H+- or ATP-dependent. In a chloride depleted medium, lowering pH or adding CN increased the uptake, suggesting that other anions could, at least partially, substitute chloride.

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Moult-related changes in the integument, midgut, and digestive gland in the freshwater amphipod Gammarus pulex

Journal of Crustacean Biology ◽

10.1163/1937240x-00002264 ◽

2014 ◽

Vol 34 (5) ◽

pp. 539-551 ◽

Cited By ~ 8

Author(s):

Mélissa Trevisan ◽

Philippe Compère ◽

Jean-Pierre Thomé ◽

Nicole Decloux ◽

Delphine Leroy

Keyword(s):

Digestive Gland ◽

Gammarus Pulex

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The fine structural distribution of acid phosphatase in the digestive gland ofArion hortensis (Fer.)

PROTOPLASMA ◽

10.1007/bf01286413 ◽

1971 ◽

Vol 73 (1) ◽

pp. 73-81 ◽

Cited By ~ 17

Author(s):

I. D. Bowen ◽

P. Davies

Keyword(s):

Acid Phosphatase ◽

Digestive Gland ◽

Structural Distribution

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Localization and Bioreactivity of Cysteine-Rich Secretions in the Marine Gastropod Nucella lapillus

Marine Drugs ◽

10.3390/md19050276 ◽

2021 ◽

Vol 19 (5) ◽

pp. 276

Author(s):

Mariaelena D’Ambrosio ◽

Cátia Gonçalves ◽

Mariana Calmão ◽

Maria Rodrigues ◽

Pedro M. Costa

Keyword(s):

Salivary Glands ◽

Digestive Gland ◽

Crude Protein ◽

Ex Vivo ◽

Gill Tissue ◽

Marine Biodiversity ◽

Nucella Lapillus ◽

Promising Target ◽

Toxin Secretion ◽

Molecular Damage

Marine biodiversity has been yielding promising novel bioproducts from venomous animals. Despite the auspices of conotoxins, which originated the paradigmatic painkiller Prialt, the biotechnological potential of gastropod venoms remains to be explored. Marine bioprospecting is expanding towards temperate species like the dogwhelk Nucella lapillus, which is suspected to secrete immobilizing agents through its salivary glands with a relaxing effect on the musculature of its preferential prey, Mytilus sp. This work focused on detecting, localizing, and testing the bioreactivity of cysteine-rich proteins and peptides, whose presence is a signature of animal venoms and poisons. The highest content of thiols was found in crude protein extracts from the digestive gland, which is associated with digestion, followed by the peribuccal mass, where the salivary glands are located. Conversely, the foot and siphon (which the gastropod uses for feeding) are not the main organs involved in toxin secretion. Ex vivo bioassays with Mytilus gill tissue disclosed the differential bioreactivity of crude protein extracts. Secretions from the digestive gland and peribuccal mass caused the most significant molecular damage, with evidence for the induction of apoptosis. These early findings indicate that salivary glands are a promising target for the extraction and characterization of bioactive cysteine-rich proteinaceous toxins from the species.

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Role of the Digestive Gland in Ink Production in Four Species of Sea Hares: An Ultrastructural Comparison

Journal of Marine Biology ◽

10.1155/2013/209496 ◽

2013 ◽

Vol 2013 ◽

pp. 1-5 ◽

Cited By ~ 3

Author(s):

Jeffrey S. Prince ◽

Paul Micah Johnson

Keyword(s):

Digestive Gland ◽

Common Ancestor ◽

Aplysia Californica ◽

Digestive Cell ◽

Digestive Cells ◽

Sea Hare ◽

Red Algal ◽

The Common ◽

Algal Chloroplast

The ultrastructure of the digestive gland of several sea hare species that produce different colored ink (Aplysia californicaproduces purple ink,A. julianawhite ink,A. parvulaboth white and purple ink, whileDolabrifera dolabriferaproduces no ink at all) was compared to determine the digestive gland’s role in the diet-derived ink production process. Rhodoplast digestive cells and their digestive vacuoles, the site of digestion of red algal chloroplast (i.e., rhodoplast) inA. californica, were present and had a similar ultrastructure in all four species. Rhodoplast digestive cell vacuoles either contained a whole rhodoplast or fragments of one or were empty. These results suggest that the inability to produce colored ink in some sea hare species is not due to either an absence of appropriate digestive machinery, that is, rhodoplast digestive cells, or an apparent failure of rhodoplast digestive cells to function. These results also propose that the digestive gland structure described herein occurred early in sea hare evolution, at least in the common ancestor to the generaAplysiaandDolabrifera. Our data, however, do not support the hypothesis that the loss of purple inking is a synapomorphy of the white-ink-producing subgenusAplysia.

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