Marine Biotechnology最新文献

Antimicrobial resistance is a critical global concern. This study explored the lipid extract (LE) of Ulva ohnoi regarding its chemical composition, antibacterial activity, and cytotoxicity against multidrug-resistant (MDR) microorganisms. The LE was characterized by GC–MS, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Antibacterial efficacy was determined by Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) against MDR isolates: Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and coagulase-negative Staphylococci (CoNS). Cytotoxicity was evaluated in murine fibroblast (L929) and bovine renal fibroblast (MDBK) cells using MTT, Neutral Red (NR), Lactate Dehydrogenase (LDH), and hemolytic activity (HA) assays. Lipid characterization revealed palmitic acid (63.62%) and oleic acid (21.01%) as major components. TGA indicated 88% mass loss, and DSC showed no amorphous/crystalline domains. LE showed favorable MIC values against S. aureus and CoNS (1.33 mg/mL) and against A. baumannii and E. coli (2 mg/mL), indicating moderate antibacterial activity typical of an unfractionated crude extract. MBC results indicated bacteriostatic activity (1–8 mg/mL). The extract was cytotoxic to L929 and MDBK cells at concentrations close to its MIC (IC₅₀ 0.25–1.95 mg/mL) but well tolerated by blood cells (HA IC₅₀ 4.705 mg/mL). U. ohnoi LE extends, rather than establishes, the previously reported antibacterial potential of Ulva lipids through comprehensive chemical characterization and MDR-isolate evaluation. However, low selectivity indices (SI < 10) indicate that the LE does not yet present an adequate therapeutic window, reinforcing the need for bioassay-guided purification. Nevertheless, it is a starting point for developing new antibacterial agents.

Graphical Abstract

Visible changes in body and internal organ coloration can serve as practical indicators of nutritional and metabolic stress in aquaculture, but their physiological meaning remains poorly understood. Here, we used starvation as a controlled nutritional stress model to investigate the physiological and molecular changes associated with body color fading and liver and gallbladder discoloration in rock carp (Procypris rabaudi). To assess the effects of food deprivation (0–35 days), fish were examined using growth and biochemical assays, intestinal histology, as well as integrated hepatic transcriptomic and metabolomic profiling. Starvation caused weight loss, reduced condition factor and hepatosomatic index, intestinal atrophy, dynamic changes in digestive enzyme activities, and a transition from early antioxidant activation to late-stage oxidative injury. It also produced a clear sequence of visible color changes, with body pigmentation fading from deep black to reddish-brown, the liver changing from dark red to pink, and the gallbladder changing from dark green or black to pale yellow or yellow-green. Multi-omics analysis associated these phenotypes with three major processes. Body color fading was associated with down-regulation of bcl-2l10, bcl-2l11, and cdk2 and depletion of tyrosine-related metabolites, suggesting possible alterations in melanogenesis-related substrate availability. Liver paling was linked to lipid and glycogen mobilization, as indicated by altered fabp and aldo expression and decreased levels of glycerophosphocholine, phosphatidylethanolamine, and phosphatidylcholine. Gallbladder discoloration was consistent with reduced expression of ho-1 and abcb11, suggesting possible involvement of pathways related to bile pigment formation and bile salt transport. Lysophosphatidic acid and demethylnobiletin were identified as candidate indicators of late-stage oxidative injury. These findings indicate that starvation-induced color changes are informative physiological phenotypes rather than superficial traits, and may support future monitoring of nutritional stress and organ dysfunction in rock carp aquaculture.

Extracellular vesicles (EVs) represent a significant advancement in the study of biological nanocarriers, facilitating intercellular communication by transferring proteins, lipids, and nucleic acids. Although there has been considerable research into mammalian-derived EVs, the exploration of marine-derived EVs is relatively limited, despite their significant potential as bioinspired biomaterials. The marine environment, characterized by extreme physicochemical conditions and significant biodiversity, produces EVs that exhibit distinctive molecular cargo, improved structural stability, and adaptive functional properties. This review presents an in-depth look of marine-derived EVs from a biomaterial’s perspective, emphasizing their biological origins, physicochemical properties, methods for isolation and purification, and advanced characterization techniques. Moreover, the mechanistic functions of marine EVs in skin regeneration are clarified, highlighting preclinical evidence supporting the application of these treatments for wound healing, inflammatory skin disorders, photoaging, pigmentation abnormalities, and skin cancer therapy. Despite the potential for favourable results, obstacles concerning large-scale production, standardization, and the translation of regulatory frameworks persist. This review highlights marine-derived EVs as a novel category of functional biomaterials, demonstrating considerable potential for advancing skin regenerative and dermatological applications in future research.

Dopamine is present in all metazoans but signaling pathways and receptors characteristics have been studied mainly in vertebrates. We addressed this issue by studying dopamine receptors in cephalopods (Sepia officinalis), a clade well-known for its visual and cognitive behavior and its production of various neurotransmitters. For the first time, we have phylogenetically identified three distinct families of dopamine receptors in Sepia embryos, belonging to the D1-like, D2-like and “invertebrate-type dopamine receptors” (INDR). We confirm that the family of INDR is not specific to Ecdysozoans and might have already been present in the ancestor of bilaterians and secondarily lost in Olfactores. Through cellular signaling assays we were able to functionally confirm the identification of Sepia dopamine receptors and show that they use three different signaling pathways. Finally we showed that all these three receptors were differentially expressed in the eyes and central nervous system of Sepia officinalis at the time of their setting-up. It is therefore likely that different dopamine receptors and different signaling pathways contribute to different physiological processes. This study opens the way to physiological and molecular studies on the organization and role of these dopaminergic system in cephalopods.

Low temperature constrains the survival and production of many cultured fishes, yet public cold-response transcriptomes differ substantially in species, developmental stage, tissue, exposure design, and genome annotation. We therefore reassessed the extent to which replicated public datasets support shared rather than universal low-temperature responses. A metadata screen identified 110 candidate BioProjects containing 1,465 runs. After manual verification of treatment relevance, sequencing platform, biological design, and read depth, 15 projects (208 runs; 10 species) were retained as a public-data landscape. Only datasets with at least three biological replicates per group and traceable processed abundance tables entered differential-expression inference: Nile tilapia (Oreochromis niloticus) adult midbrain (four cold and four control samples) and zebrafish (Danio rerio) whole larvae (three cold and three matched controls at five time points). Differentially expressed genes were defined by false discovery rate (FDR) < 0.05 and |log2 fold change| >= 1. Unbiased Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses identified recurrent rhythmic/transcriptional, MAPK-FoxO stress-signaling, cell-fate, innate-immune, and metabolic themes. Ensembl one-to-one orthology restricted the primary cross-species comparison to 6,383 expression-mapped gene pairs. Thirty-two pairs showed concordant differential expression in tilapia and zebrafish at 24 h, whereas six were discordant. Candidate counts ranged from 10 to 91 across prespecified FDR and effect-size thresholds. Replicated common carp (Cyprinus carpio) brain and heart results were used as an external, paralogue-aware check: 11 of the 32 pairs received same-direction support, three showed an opposite response, and 18 lacked strong support. nr1d1, bhlhe40, dusp1, plin2, pprc1, and pfkfb3 illustrate conserved primary responses together with tissue- and lineage-dependent divergence. These associations generate focused hypotheses for experimental testing but do not establish causal cold-tolerance genes.

Aquaculture of the giant river prawn Macrobrachium rosenbergii faces ongoing challenges associated with aberrant gonadal development, precocious puberty and inefficient sex manipulation techniques. Although microRNAs (miRNAs) serve as critical regulators of spermatogenesis across diverse taxa, their roles in modulating testicular development of M. rosenbergii remain largely uncharacterized. In this study, we performed small RNA sequencing on testicular tissues of M. rosenbergii at three representative developmental stages to profile genome-wide miRNA expression dynamics during spermatogenesis. A total of 173 miRNAs (including 12 novel miRNAs) were identified, and several key miRNAs exhibiting significant temporal expression differences were screened. GO and KEGG enrichment analyses revealed that target genes of these miRNAs were primarily involved in pathways related to sex differentiation, hormone synthesis, and energy metabolism. Further analysis indicated that miRNAs such as miR-1-3p and miR-317-3p may activate the testis developmental program during early developmental stages, while the downregulation of negative regulators like miR-124-3p and miR-210-3p may contribute to the release of developmental inhibition. A subset of miRNAs including miR-8-3p and miR-315-5p may exert regulatory effects on the IAG signaling axis through targeting genes such as ferritin and Fem-1c, thereby modulating testicular maturation. Additionally, the observed downregulation of miRNAs implicated in innate immune response and chitin metabolism points to a reconfiguration of regulatory priorities during the rapid phase of testicular growth to support reproductive development. The study contributes to a deeper understanding of miRNA-mediated regulatory mechanisms underlying crustacean development and reproduction.

Larval development in marine mollusks requires coordinated gene regulation and is particularly sensitive to ocean acidification, yet post-transcriptional regulation remains poorly characterized in non-model gastropods. We characterized the microRNA (miRNA) repertoire and respiratory response of red abalone (Haliotis rufescens) larvae reared at pH 8.0 and 7.6. Small-RNA sequencing was performed at the trochophore (24 h post-fertilization, hpf) and competent veliger (110 hpf) stages, with three biological replicates per stage and pH treatment, while oxygen consumption was measured at 24, 48, 60, and 110 hpf. Genome-anchored annotation identified 147 precursor loci encoding 117 distinct mature miRNA sequences, including 70 matching reference databases and 47 candidate novel miRNAs. The developmental stage was the predominant source of variation in miRNA abundance, with the first principal component explaining 87.3% of the variation, whereas acidification affected a comparatively small subset of miRNAs. Cumulative oxygen consumption from 24 to 110 hpf was 57% higher at pH 7.6 than at pH 8.0. Both intergenic and intragenic miRNAs contributed to the acidification-associated response, with no significant preferential representation of either genomic-origin class. Computational predictions link pH-responsive miRNAs to genes associated with aerobic metabolism, morphogenesis, biomineralization, chromatin regulation, and stress responses. Because these miRNA–target relationships are computational predictions and the physiological and molecular measurements were not biologically paired, they do not establish a direct regulatory relationship. These results provide the first larval miRNA catalogue for H. rufescens and identify developmental- and acidification-associated miRNA abundance patterns and candidate miRNA–target relationships for future functional validation.

Elucidating the metabolic basis of sexual dimorphism is critical for the effective management of sequential hermaphrodites in aquaculture. The four-finger threadfin (Eleutheronema tetradactylum) is a commercially significant protandrous species; however, the metabolic landscapes characterizing its sexual maturity remain unexplored. In this study, we established a foundational metabolomic baseline by profiling brain and gonad tissues from sexually mature males and females using UHPLC-Q-TOF-MS. Multivariate statistical analysis revealed distinct tissue-specific dimorphism, with gonadal tissues exhibiting significantly greater sex-specific metabolic divergence than neural tissues. We identified sex-specific alterations in key metabolic networks, including aminoacyl-tRNA biosynthesis, nucleotide metabolism (purine/pyrimidine), and the glutamine-glutamate axis, which collectively support the high biosynthetic demands of ovarian development. Notably, the brain exhibited subtle yet specific shifts in neuro-lipid signaling, including arachidonic acid metabolism and tryptophan pathways, suggesting a neuroendocrine regulatory role rather than global metabolic remodeling. To our knowledge, this is the first tissue-resolved metabolomic dataset for a protandrous hermaphrodite fish. This study establishes a preliminary metabolomic baseline of biochemical differentiation in E. tetradactylum, identifying candidate biomarkers for sex identification and providing a foundation for future investigation into the metabolic regulation of protandrous hermaphroditism.

Intertidal burrowing bivalves, such as razor clam Sinonovacula constricta, are economically significant aquaculture species in coastal China. However, they exhibit high susceptibility to heat stress under global warming, which poses a substantial challenge to aquaculture sustainability and production. While several studies have identified genes responsive to heat stress in S. constricta, the regulatory mechanisms and core networks underlying these responses remain poorly understood. Non-coding RNAs (ncRNAs) play a crucial role in gene regulation. To investigate the function of ncRNAs and their associated regulatory networks during both heat stress and recovery, this study employed transcriptomic and miRNA transcriptomic analyses, enrichment analysis of key responsive genes, network construction, and dual-luciferase reporter assays. The results showed that, in contrast to other species, more than 7 of the top 10 most significantly responsive genes in S. constricta during heat stress were heat shock protein 70 (HSP70) genes, while the number of HSP genes sharply decreased (to 3 or 0) during recovery. Enrichment analysis revealed that protein stability and folding were critical response processes during heat stress, whereas catabolism dominated during the recovery phase. Network analysis identified Bcl-2-associated athanogene 3 (BAG3), miR-m0017-5p, and lnc9737 as the core genes, in the heat stress response. Dual-luciferase reporter assays demonstrated that lnc9737 might act as a ceRNA in the miR-m0017-5p/BAG3 axis during heat stress. This research enhances our understanding of heat stress responses in these key aquaculture species and identifies molecular targets for selective breeding to improve thermal tolerance in razor clam farming.

Algae are characterized by lineage-specific storage and structural carbohydrates; however, the metabolic pathways governing these compounds remain largely uncharacterized despite their high commercial value in the food, pharmaceutical, and nutraceutical sectors. This study addresses this knowledge gap through a comprehensive genome-wide analysis of Carbohydrate-Active Enzymes (CAZymes) across green, red, and brown algae. By utilizing functional homology searches, the CAZyme repertoires of these lineages were identified. Systematic comparative profiling revealed both distinct lineage-specific “glycobiomes” and a core set of conserved enzymes shared across these groups. Additionally, phylogenetic and conserved sequence motif analyses were integrated to provide functional interpretations that link CAZymes to unique cell wall compositions and carbon reserves. Furthermore, the results offer deeper insights into the potential CAZymes driving the biosynthesis of sulfated algal polysaccharides. By mapping these complex biosynthetic enzymes, this study establishes a foundation for the biotechnological and industrial exploitation of algal glycans.