Marine Biotechnology最新文献

The abundance of nanoplastics (NPs) in marine ecosystems has raised significant concerns about their potential ecotoxicological effects, primarily on sessile bivalves. The present evaluation aimed to assess the toxico-transcriptomic impact of polystyrene nanoplastics (PS-NPs) on the intertidal clam, Gafrarium divaricatum. The clams were subjected to PS-NPs (10 mg/L) for 96 h, and the gill tissues were collected for transcriptomic and histopathological analyses. The de novo transcriptome assembly, performed using Trinity, generated 661,554 unigenes with a BUSCO completeness of 98.8%, establishing a high-quality genomic resource for this species. Differential gene expression analysis identified 1,182 upregulated and 1,626 downregulated transcripts, with major functional categories related to immune modulation, antioxidant defence, apoptosis, and cellular architectural changes, that are broadly consistent with NP-induced responses previously documented in other bivalves. Gene ontology enrichment analysis revealed involvement of genes in important molecular activities like transporter and catalytic activity, as well as biological processes like protein folding and mitochondrial metabolism. The q-PCR analysis of selected transcripts further confirmed the consistency of the expression pattern in line with RNA-Seq data. The histopathological examination revealed marked structural alterations in gill tissues, including ciliary erosion, lamellae fusion, and lipofuscin granular accumulation, supplementing the transcriptomic findings of tissue-level toxicity. These molecular responses corroborate with established NP-related stress patterns in bivalves. This study represents the first transcriptome resource for this species and provides greater insights into the molecular mechanisms underlying NP toxicity in marine bivalves, contributing to broader efforts for developing suitable strategies for conservation of marine biodiversity.

Predator-prey interactions in marine ecosystems are extremely complex, involving a wide variety of species. In contrast, toxin-mediated predator-prey interactions are constrained by species-specific tolerance to the toxin. Tetrodotoxin (TTX), commonly known as pufferfish toxin, is a common factor in such interactions across diverse taxa. It has been recently suggested that TTX-bearing planocerid flatworms contribute to the toxification of other TTX-bearing organisms. However, their contribution to the transfer of TTX in the food web remains unclear. In this study, we investigated the trophic position of the TTX-bearing flatworm Planocera multitentaculata in this transfer using carbon and nitrogen stable isotope analysis. We compared isotope values from wild P. multitentaculata, its putative prey (mollusks such as gastropods and polyplacophorans), and a known predator, the pufferfish Takifugu alboplumbeus. We also reared P. multitentaculata exclusively on the gastropod Monodonta confusa and estimated the trophic enrichment factors for stable isotopes of carbon and nitrogen to be 0.85‰ and 3.28‰, respectively. Based on these findings, the inferred prey of the wild flatworm had stable isotope values similar to those of the gastropod M. confusa and two polyplacophoran species. In contrast, the inferred prey of T. alboplumbeus had significantly different isotope values from P. multitentaculata, supporting the role of flatworms as an intermediate TTX source in marine food webs. These results highlight the importance of planocerid flatworms in TTX transfer and their contribution to toxin accumulation at higher trophic levels.

Siniperca scherzeri is an economically important freshwater species in East Asia, characterized by high market value and considerable breeding potential. To elucidate the genetic underpinnings of growth traits and evaluate the feasibility of genomic selection (GS) in this species, we employed whole-genome resequencing data to estimate genetic parameters and conduct genomic prediction analyses for five growth traits: body weight, body length, extended length, body height, and body thickness. We compared six GS models—GBLUP, BayesA, BayesB, BayesC, BayesL, and BayesRR—and assessed the effects of marker density and SNP selection strategies on prediction ability. The growth traits exhibited generally low-to-moderate heritability; notably, body length (BL) and extended length (EL) showed higher estimates (0.224 and 0.208, respectively), suggesting priority targets for genetic improvement. Across the six models, prediction ability was moderate overall (0.16–0.31), with GBLUP delivering relatively high and stable performance. Further analyses demonstrated that GWAS-informed SNP selection markedly outperformed random selection, enabling high prediction ability at reduced marker densities. In particular, for BL and EL, panels with only 500 SNPs achieved high prediction ability (0.70), while random selection reached prediction levels comparable to the whole-genome set at 1 K SNPs. Thus, low-density marker panels can substantially reduce genotyping costs while maintaining prediction ability. Collectively, these findings delineate the genetic characteristics of growth in S. scherzeri, validate the feasibility of GWAS-guided marker selection for GS, and provide a sound theoretical basis and practical reference for molecular breeding and genetic improvement in aquaculture species.

The small yellow croaker (Larimichthys polyactis) is an important mariculture fish species, which necessitates systematic genetic analysis of growth-related traits to accelerate precision breeding. To address this, 1051 individuals from 26 full-sib families were evaluated as part of this study to determine the genetic parameters of nine growth-related traits at 10 months of age: total length, body length, head length, body height, caudal peduncle length, caudal peduncle height, trunk length, tail length and body weight. Family-level inbreeding coefficients ranged from 0.125 to 0.438, indicating moderate to high genetic relatedness within families. Genetic parameters were estimated with a single-trait animal model in which the corresponding trait measured at 6-month of age fitted as a linear covariate and days of age was included as a fixed effect. Heritability estimates for individual traits were moderate (0.29–0.42). Positive genetic and phenotypic correlations between trait pairs were consistently, ranging from 0.55 to 0.99, and 0.49 to 0.98, respectively. Repeatability estimates for the traits tested ranged from 0.60 to 0.87. Under a 30% selection ratio, the predicted genetic gain and relative genetic gain for body weight in the next generation were 3.54 and 7.95%, respectively. These results provide a robust framework for the development of selective breeding programs in small yellow croaker, enabling targeted enhancement of growth performance in aquaculture operations.

To address the challenge of fishmeal shortage and improve the utilization of fishmeal-free (FMF) diets in large yellow croaker (Larimichthys crocea), we conducted an integrative analysis combining host genetics and gut microbiota. A 28-day indoor feeding trial was performed with 185 fish using an FMF-based diet, during which single nucleotide polymorphism (SNP) genotyping and feed efficiency evaluations were conducted. The V3-V4 regions of the 16S rRNA gene were sequenced from both distal (DI) and proximal (PI) intestinal segments. Significant microbial contributions (microbiability) were only observed for daily feed intake (DFI) and residual feed intake (RFI). Microbiability estimates reached 0.25 (DI) and 0.17 (PI) for DFI, while RFI in DI exhibited higher microbiability (m² = 0.11) than heritability (h² = 0.08). In contrast, correlations between host genetic variation and microbial community distances were extremely weak. We further identified heritable microbial taxa, including Lactococcus, Alicyclobacillus acidoterrestris, and Bacillus, as well as microbial biomarkers such as Lactococcus, Listeria, Methylobacterium, and Alicyclobacillus acidoterrestris, which were significantly associated with FMF feed adaptation. These findings highlight the complementary roles of host genetics and gut microbiota in shaping FMF feed utilization in marine fish, and provide valuable targets for selective breeding of strains with enhanced adaptability to plant-based diets.

Heavy metal bioaccumulation in marine organisms is a critical concern for the oceanic environment and food safety. Scallops, as filter-feeding bivalves, accumulate cadmium (Cd) in their midgut gland to toxic concentrations that may pose risks to human health. Despite extensive research on Cd bioaccumulation in the Yesso scallop Mizuhopecten yessoensis, a major Cd-binding protein has not yet been functionally characterized. In this study, we used high-performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) to isolate Cd-binding proteins, and identified myCRP, a novel high-molecular-weight Cd-binding protein. myCRP contains a cysteine-rich sequence, resembling metallothionein Cd-binding motifs, and is expressed exclusively in the midgut gland. Cd-binding assays demonstrated that myCRP binds Cd in a dose-dependent manner. Immunostaining revealed the presence of a small cluster of myCRP-containing cells in the connective tissue surrounding digestive tubules in the midgut gland. Synchrotron radiation X-ray fluorescence (SR-XRF) analyses showed the distribution of Cd throughout the entire midgut gland tissue. We conclude that myCRP is partly responsible for Cd binding in the midgut gland. Our findings clarify a new mechanism of Cd-binding in marine organisms from both biological and molecular perspectives.

Histidine-related compounds (HRCs) are pleiotropic, ergogenic molecules implicated in exercise performance enhancement, yet their distribution, mechanistic actions, and metabolic regulation in skeletal muscle remain poorly defined. Herein, we performed comparative analysis using three teleost fish species with distinct swimming strategies: the sustained swimmer Pseudocaranx dentex, the prolonged swimmer Takifugu rubripes, and the burst swimmer Paralichthys olivaceus. The aerobic, anaerobic, antioxidant, and buffering (βm) capacities of slow-twitch muscle (SM) and fast-twitch muscle (FM) were measured and their correlations with HRCs content were assessed. Our results confirmed that FM consistently exhibits higher anaerobic capacity and βm across all species, whereas SM possesses superior aerobic and antioxidant capacities. Species rankings for these capacities: P. dentex > T. rubripes > P. olivaceus, confirming they were effective models for investigating HRC mechanism in skeletal muscles. A significantly higher HRC content in FM, compared to SM, was observed exclusively in P. dentex, which also possessed the highest overall HRC content compared to the other species. This pattern suggests a less prominent role for HRCs in highly oxidative SM, where their content was markedly low. Strong positive correlations were identified between HRC content with both anaerobic and buffering capabilities, supporting their role as intramuscular pH regulators. Quantitative gene expression analysis further identified Slc15a4 and Slc7a2 as putative key regulators of HRCs metabolism, based on their conserved high expression in FM and strong correlation with interspecific HRCs accumulation. Collectively, our results provide a valuable insight into the role and regulation of HRCs in the skeletal muscle of teleost fishes.

The Fibroblast Growth Factor (FGF) gene family of Nile tilapia plays a central role in environmental adaptation and aquaculture resilience. This study integrated in silico analyses and molecular docking to comprehensively analyze the FGF gene family in Nile tilapia. Phylogenetic reconstruction identified three clades (A-C): In Group A, the subclade of genes (FGF19/21/23) revealed conserved endocrine and metabolic roles. Group B genes (FGF7/8a/8b/17/18/24) retained ancestral development functions linked to teleost-specific genome duplication. In Group C, the subclade of genes (FGF1/2/5) exhibiting sub-functionalization, such as FGF2 wound healing versus FGF5 mitogenic roles. The structural analysis highlighted the conserved β-trefoil domain, critical for receptor binding, alongside lineage-specific innovation like heparin-binding motifs in FGF. Physicochemical properties observed a high aliphatic index (AI) of 101.68 in FGF19, which is crucial for climate adaptation. Molecular docking revealed novel predicted interactions, such as FGF4/17 with androgen receptor (AR), potentially influencing male reproduction, while KLF5/DDBI binding expanded FGF roles to gill regeneration and oxidative damage mitigation. Glucocorticoid (GR) exhibited the most potent predicted interaction with a high docking score (− 233.99 to − 313.15), particularly for FGF4 (− 310.86), and FGF8a (− 313.15), suggesting conserved GR-mediated regulation for metabolism, inflammation, and tissue repair. This study pioneers the exploration of potential cross-talk between FGF proteins and nuclear receptors, and provides insights into the link between FGF structural evolution and aquaculture resilience. By bridging genomic features and environmental adaptation, this research contributes to a better understanding of Nile tilapia’s potential as a model for sustainable aquaculture.

Graphical Abstract

A new cyclic dipeptide, cyclo(phenylalanine–proline) (cFP), was isolated from the marine bacterium Exiguobacterium profundum SW22 and characterized by NMR and high-resolution mass spectrometry. In silico profiling predicted favorable pharmacokinetic and drug-like properties for cFP. The compound demonstrated dose-dependent cytotoxicity against human breast (MDA MB-231), pancreatic (PAN C1), and prostate (PC 3) cancer cell lines with IC₅₀ values of 47.24 ± 0.42, 40.96 ± 0.68, and 110 ± 1.48 µM, respectively, accompanied by apoptosis-associated morphological changes. Biophysical studies demonstrated strong binding affinity between cFP and human serum albumin (HSA), confirmed through UV-visible absorption spectroscopy, fluorescence quenching, and circular dichroism analyses, with validation using well-characterized reference ligand warfarin as control. Results suggest static quenching via ground-state complex formation with negligible lifetime changes, consistent with control molecule (warfarin) binding via hydrogen bonding and van der Waals interactions, accompanied by ligand-induced decreases in HSA α-helical content. Molecular docking studies of HSA with cFP and warfarin revealed strong binding affinities for both compounds. Further, the molecular dynamics simulations over a 50 ns timeframe confirmed the enhanced stability and persistent interaction of the cFP-HSA complex. Results highlight the cFP as a promising bioactive peptide with potential anticancer, pharmacokinetic and serum binding efficacies advocating further preclinical development for anticancer therapy.

Swimming performance is critical to the survival of fish, influencing behaviors such as foraging, predator avoidance, and habitat selection. However, most previous studies have focused on a single type of swimming performance, with limited attention to the integration and interrelation of different swimming performances within the same individual. In this study, we systematically evaluated the relationships among critical swimming speed (U_crit), burst swimming speed (U_burst), and endurance time in the large yellow croaker (Larimichthys crocea), and investigated the physiological basis underlying individual variation in swimming performance. Using three distinct swimming test protocols, we comprehensively evaluated various types of swimming performance in the same fish. Our findings revealed that the distributions of U_crit, U_burst, and endurance time approximated normality, with U_crit displaying significant positive correlations with both U_burst and endurance duration. Histological observations revealed qualitative structural differences in red muscle between groups. Superior swimmers (SS) exhibited more orderly and compact red muscle myofibrils and better-preserved mitochondrial morphology, whereas inferior swimmers (IS) showed disrupted myofibrillar organization and mitochondrial damage. Moreover, these SS individuals exhibited significantly higher activities of key metabolic enzymes (phosphofructokinase, pyruvate kinase, lactate dehydrogenase, and citrate synthase) in white muscle tissue. Together, these results indicate that muscle structural characteristics and metabolic enzyme capacities contribute to individual variation in swimming performance. Our findings highlight that swimming performance is a complex integrative trait shaped by multiple interacting physiological factors, and provide a theoretical foundation for improving the health, welfare, and sustainability of offshore aquaculture practices for large yellow croaker.