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Current Biology : CB Aug 2019Cephalopods have captivated the minds of scientists for thousands of years, dating back to approximately 330 BC when Aristotle became fascinated by their ability to...
Cephalopods have captivated the minds of scientists for thousands of years, dating back to approximately 330 BC when Aristotle became fascinated by their ability to rapidly change colour. This remarkable ability, however, is not the only aspect of cephalopod behaviour that has garnered attention from the scientific community. The soft-bodied cephalopods (henceforth cephalopods), namely octopus, cuttlefish, and squid, are widely considered to be the most cognitively advanced group of invertebrates. They possess highly developed perceptual, memory, and spatial learning abilities and are also capable of intriguing feats of behaviour that appear to indicate complex cognition.
Topics: Animals; Cognition; Decapodiformes; Memory; Octopodiformes; Perception; Spatial Learning
PubMed: 31386844
DOI: 10.1016/j.cub.2019.06.049 -
Philosophical Transactions of the Royal... May 2021The first animal mitochondrial genomes to be sequenced were of several vertebrates and model organisms, and the consistency of genomic features found has led to a... (Review)
Review
The first animal mitochondrial genomes to be sequenced were of several vertebrates and model organisms, and the consistency of genomic features found has led to a 'textbook description'. However, a more broad phylogenetic sampling of complete animal mitochondrial genomes has found many cases where these features do not exist, and the phylum Mollusca is especially replete with these exceptions. The characterization of full mollusc mitogenomes required considerable effort involving challenging molecular biology, but has created an enormous catalogue of surprising deviations from that textbook description, including wide variation in size, radical genome rearrangements, gene duplications and losses, the introduction of novel genes, and a complex system of inheritance dubbed 'doubly uniparental inheritance'. Here, we review the extraordinary variation in architecture, molecular functioning and intergenerational transmission of molluscan mitochondrial genomes. Such features represent a great potential for the discovery of biological history, processes and functions that are novel for animal mitochondrial genomes. This provides a model system for studying the evolution and the manifold roles that mitochondria play in organismal physiology, and many ways that the study of mitochondrial genomes are useful for phylogeny and population biology. This article is part of the Theo Murphy meeting issue 'Molluscan genomics: broad insights and future directions for a neglected phylum'.
Topics: Animals; Gene Duplication; Gene Rearrangement; Genome, Mitochondrial; Heredity; Mollusca
PubMed: 33813887
DOI: 10.1098/rstb.2020.0159 -
Current Biology : CB Oct 2023Cephalopod molluscs are renowned for their unique central nervous system - a donut-shaped brain organised around the oesophagus. This brain supports sophisticated...
Cephalopod molluscs are renowned for their unique central nervous system - a donut-shaped brain organised around the oesophagus. This brain supports sophisticated learning and memory abilities. Between the 1950s and 1980s, these cognitive abilities were extensively studied in octopus (Figure 1A) - a now leading model for the study of memory and its neural substrates (approximately 200 papers during this period). The focus on octopus learning and memory was mainly due to their curious nature and the fact that they adapt to laboratory-controlled conditions, making them easy to test and maintain in captivity. Research on cephalopod cognition began to widen in the late 20th century, when scientists started focusing on other coleoid cephalopods (i.e., cuttlefish and squid) (Figure 1B,C), and not just on associative learning and memory per se, but other more complex aspects of cognition such as episodic-like memory (the ability to remember the what, where, and when of a past event), source memory (the retrieval of contextual details from a memory), and self-control (the ability to inhibit an action in the present to gain a more valuable future reward). Attention broadened further over the last two decades to focus on the shelled cephalopods - the nautiloids (Figure 1D). The nautiloids have relatively primitive brains compared to their soft-bodied cousins (octopus, cuttlefish, and squid) but research shows that they are still able to comparatively succeed in some cognitive tasks. In this primer, we will provide a general description of the types of memory studied in cephalopods, and discuss learning and memory experiments that address the main challenges cephalopods face during their daily lives: navigation, timing, and food selection. Determining the type of information cephalopods learn and remember and whether they use such information to overcome ecological challenges will highlight why these invertebrates evolved large and sophisticated brains.
Topics: Animals; Learning; Brain; Cognition; Decapodiformes; Octopodiformes
PubMed: 37875090
DOI: 10.1016/j.cub.2023.08.013 -
Current Biology : CB Oct 2023Allard et al. describe the remarkable 'taste by touch' abilities of cephalopods, in particular octopuses.
Allard et al. describe the remarkable 'taste by touch' abilities of cephalopods, in particular octopuses.
Topics: Animals; Cephalopoda; Octopodiformes; Touch; Touch Perception
PubMed: 37875087
DOI: 10.1016/j.cub.2023.08.011 -
Viruses Sep 2021According to the 2018 FAO report on aquaculture, there are 598 species of finfish, molluscs, crustaceans, and other organisms used in aquafarming around the world [...].
According to the 2018 FAO report on aquaculture, there are 598 species of finfish, molluscs, crustaceans, and other organisms used in aquafarming around the world [...].
Topics: Animals; Aquaculture; Crustacea; Fishes; Infectious pancreatic necrosis virus; Mollusca; Rhabdoviridae; Salmon; Viruses
PubMed: 34578358
DOI: 10.3390/v13091777 -
Marine Drugs Dec 2020The natural products of heterobranch molluscs display a huge variability both in structure and in their bioactivity. Despite the considerable lack of information, it can... (Review)
Review
The natural products of heterobranch molluscs display a huge variability both in structure and in their bioactivity. Despite the considerable lack of information, it can be observed from the recent literature that this group of animals possesses an astonishing arsenal of molecules from different origins that provide the molluscs with potent chemicals that are ecologically and pharmacologically relevant. In this review, we analyze the bioactivity of more than 450 compounds from ca. 400 species of heterobranch molluscs that are useful for the snails to protect themselves in different ways and/or that may be useful to us because of their pharmacological activities. Their ecological activities include predator avoidance, toxicity, antimicrobials, antifouling, trail-following and alarm pheromones, sunscreens and UV protection, tissue regeneration, and others. The most studied ecological activity is predation avoidance, followed by toxicity. Their pharmacological activities consist of cytotoxicity and antitumoral activity; antibiotic, antiparasitic, antiviral, and anti-inflammatory activity; and activity against neurodegenerative diseases and others. The most studied pharmacological activities are cytotoxicity and anticancer activities, followed by antibiotic activity. Overall, it can be observed that heterobranch molluscs are extremely interesting in regard to the study of marine natural products in terms of both chemical ecology and biotechnology studies, providing many leads for further detailed research in these fields in the near future.
Topics: Animals; Biological Products; Snails
PubMed: 33371188
DOI: 10.3390/md18120657 -
Marine Drugs Mar 2020Heterobranch molluscs are rich in natural products. As other marine organisms, these gastropods are still quite unexplored, but they provide a stunning arsenal of... (Review)
Review
Heterobranch molluscs are rich in natural products. As other marine organisms, these gastropods are still quite unexplored, but they provide a stunning arsenal of compounds with interesting activities. Among their natural products, terpenoids are particularly abundant and diverse, including monoterpenoids, sesquiterpenoids, diterpenoids, sesterterpenoids, triterpenoids, tetraterpenoids, and steroids. This review evaluates the different kinds of terpenoids found in heterobranchs and reports on their bioactivity. It includes more than 330 metabolites isolated from ca. 70 species of heterobranchs. The monoterpenoids reported may be linear or monocyclic, while sesquiterpenoids may include linear, monocyclic, bicyclic, or tricyclic molecules. Diterpenoids in heterobranchs may include linear, monocyclic, bicyclic, tricyclic, or tetracyclic compounds. Sesterterpenoids, instead, are linear, bicyclic, or tetracyclic. Triterpenoids, tetraterpenoids, and steroids are not as abundant as the previously mentioned types. Within heterobranch molluscs, no terpenoids have been described in this period in tylodinoideans, cephalaspideans, or pteropods, and most terpenoids have been found in nudibranchs, anaspideans, and sacoglossans, with very few compounds in pleurobranchoideans and pulmonates. Monoterpenoids are present mostly in anaspidea, and less abundant in sacoglossa. Nudibranchs are especially rich in sesquiterpenes, which are also present in anaspidea, and in less numbers in sacoglossa and pulmonata. Diterpenoids are also very abundant in nudibranchs, present also in anaspidea, and scarce in pleurobranchoidea, sacoglossa, and pulmonata. Sesterterpenoids are only found in nudibranchia, while triterpenoids, carotenoids, and steroids are only reported for nudibranchia, pleurobranchoidea, and anaspidea. Many of these compounds are obtained from their diet, while others are biotransformed, or biosynthesized by the molluscs. Overall, a huge variety of structures is found, indicating that chemodiversity correlates to the amazing biodiversity of this fascinating group of molluscs.
Topics: Animals; Mollusca; Oceans and Seas; Terpenes
PubMed: 32183298
DOI: 10.3390/md18030162 -
Marine Drugs Nov 2023R-type lectins are a widespread group of sugar-binding proteins found in nearly all domains of life, characterized by the presence of a carbohydrate-binding domain that... (Review)
Review
R-type lectins are a widespread group of sugar-binding proteins found in nearly all domains of life, characterized by the presence of a carbohydrate-binding domain that adopts a β-trefoil fold. Mytilectins represent a recently described subgroup of β-trefoil lectins, which have been functionally characterized in a few mussel species (Mollusca, Bivalvia) and display attractive properties, which may fuel the development of artificial lectins with different biotechnological applications. The detection of different paralogous genes in mussels, together with the description of orthologous sequences in brachiopods, supports the formal description of mytilectins as a gene family. However, to date, an investigation of the taxonomic distribution of these lectins and their molecular diversification and evolution was still lacking. Here, we provide a comprehensive overview of the evolutionary history of mytilectins, revealing an ancient monophyletic evolutionary origin and a very broad but highly discontinuous taxonomic distribution, ranging from heteroscleromorphan sponges to ophiuroid and crinoid echinoderms. Moreover, the overwhelming majority of mytilectins display a chimera-like architecture, which combines the β-trefoil carbohydrate recognition domain with a C-terminal pore-forming domain, suggesting that the simpler structure of most functionally characterized mytilectins derives from a secondary domain loss.
Topics: Animals; Lectins; Evolution, Molecular; Bivalvia; Carbohydrates
PubMed: 38132935
DOI: 10.3390/md21120614 -
Marine Drugs Oct 2020Marine organisms are constantly exposed to variations in physical parameters (e [...].
Marine organisms are constantly exposed to variations in physical parameters (e [...].
Topics: Animals; Aquatic Organisms; Diatoms; Marine Toxins; Mollusca; Mucus; Oxylipins
PubMed: 33080956
DOI: 10.3390/md18100518 -
Biomolecules Dec 2021Molluscs display a sophisticated N-glycan pattern on their proteins, which is, in terms of involved structural features, even more diverse than that of vertebrates. This... (Review)
Review
Molluscs display a sophisticated N-glycan pattern on their proteins, which is, in terms of involved structural features, even more diverse than that of vertebrates. This review summarises the current knowledge of mollusc N-glycan structures, with a focus on the functional aspects of the corresponding glycoproteins. Furthermore, the potential of mollusc-derived biomolecules for medical applications is addressed, emphasising the importance of mollusc research.
Topics: Animals; Carbohydrate Sequence; Glycoproteins; Glycosylation; Mollusca; Polysaccharides
PubMed: 34944464
DOI: 10.3390/biom11121820