Marine Biotechnology最新文献

Given the challenges of overcrowded coastal aquaculture spaces and insufficient production, utilizing saline-alkaline water areas represents a vital strategy to alleviate these bottlenecks. Spotted sea bass (Lateolabrax maculatus), with its formidable osmoregulatory capabilities, is an ideal candidate to develop a saline-alkaline tolerant strain. In our study, genotypic and phenotypic data from 287 L. maculatus individuals exposed to carbonate alkaline conditions were collected, and a genome-wide association study (GWAS) conducted to elucidate genetic basis related to carbonate alkalinity tolerance trait. Results showed that 14 SNPs and 8 InDels were markedly related to carbonate alkalinity tolerance trait, and 404 candidate genes were pinpointed within a ± 300-kb region surrounding these variants. Notably, the most significant SNP (SNP_05_17240108), along with two adjacent SNPs (SNP_05_17240102 and SNP_05_17240340) and two InDels (InDel_05_17240228 and InDel_05_17240231), was situated in the intron region of trio gene that could play vital roles in cell remodeling, and cell junction and activity of aquaporins to deal with carbonate alkalinity stress. Furthermore, candidate genes were significantly involved in pathways associated with carbohydrate metabolism, cell remodeling, ion transport, and RNA degradation, which were consistent with RNA-Seq analysis results of gills and kidneys in response to alkalinity stress. Our study will contribute to elucidate the genetic basis of alkalinity tolerance and the identified SNPs and InDels could be used for marker-assisted selection (MAS) and genomic selection (GS) for alkalinity tolerance trait in the breeding programs of spotted sea bass.

Burn wounds are challenging to treat due to considerable tissue damage and fluid loss. Creating wound dressings from natural and biological materials makes it possible to treat wounds and promote rapid epithelialization to speed healing and restore skin function. As a result, the ability of a collagen scaffold (Col) made from rainbow trout (Oncorhynchus mykiss) and putative bioactive phytochemical components from a Sargassum glaucescens (S. glaucescens) extract (SGE) to promote burn wound healing was assessed in this work. Synthesized collagen (40 mg/ml)/SGE (1–3 mg/ml) samples were then characterized physiochemically and physiologically. The physicochemical examination validated the bioactive component of SGE, the type of collagen (type I, α1, and α2), the successful incorporation of SGE into collagen scaffolds (Col/SGE), the thermal stability, and excellent hydrophilicity and water absorption capacity of produced scaffolds. Moreover, biological experiments approved the excellent antioxidant and antibacterial activity of SGE, structural stability improvement against degradation, and cell proliferation enhancement without cell toxicity. The results showed the Col/SGE 3 mg/ml sample also had the highest level of cell activity, according to the antibacterial and cell viability assays. Additionally, using Col/SGE in vivo on burn wounds in rat models demonstrated a quicker rate of wound healing with stronger re-epithelialization and dermal remodeling, fewer inflammatory cells, more fibroblast cells, and great collagen buildup. Therefore, since the collagen/SGE scaffold is structurally stable and can potentially promote cell proliferation without causing cell toxicity, the acquired results suggested that it may significantly impact wound healing.

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The Pacific oyster Crassostrea gigas is rich in taurine, a conditionally essential amino acid functioning in anti-oxidation, anti-inflammation, anti-aging, osmoregulation, and neuromodulation. Breeding oyster varieties with enhanced taurine content is significant to meet people’s demand for high-quality oysters. In the present study, polymorphisms in the oyster cysteamine dioxygenase (CgADO) gene that encodes the central enzyme of the cysteamine pathway for taurine synthesis were investigated, and their association with taurine content was assessed in the Changhai (CH) and Qinhuangdao (QHD) populations. A total of 47 single nucleotide polymorphism (SNP) loci were identified in the exonic region of CgADO through Sanger sequencing, with a synonymous SNP (c.415T>C) showing a significant association with taurine content. Oysters with the CT genotype at c.415T>C exhibited higher taurine content than those with the TT genotype (p < 0.05). Moreover, a significant difference in the CgADO mRNA expression was observed between oysters with different genotypes, with higher expression in the CT genotype compared to the TT genotype (p < 0.001). These findings indicate the potential influence of CgADO polymorphisms on taurine content in C. gigas and provide candidate functional markers for the selective breeding of oyster varieties with improved taurine levels.

Triploids are widely used to rapidly achieve genetic improvements of organisms due to their fast growth and enhanced environmental adaptability. Artificially induced triploids are generally considered to be infertile owing to the obvious inhibition of gonadal development. Recently, some fertile individuals with reduced advantages have been found in triploid bivalves, which is a notable deviation from the original intention of artificially inducing triploids. This study utilized dwarf surf clams (Mulinia lateralis), a promising model organism of bivalves, to develop a model for exploring the potential mechanism of triploid reproduction. The results showed that the optimal induction condition for triploid M. lateralis, determined by orthogonal experiments, was 0.5 mg/L cytochalasin B (CB) to inhibit PB2 for 20 min, resulting in a triploidy rate of 95.57% and a hatching rate of 60.25%. By tracking the development of M. lateralis, we found that the induced triploids could develop normally to maturity and exhibited significant growth and survival advantages post-metamorphosis. Although the triploidy rate exhibited a slight decline overtime, it remained high, with a ratio of 90.63% at 120 dpf. Histological observation confirmed that the gonadal development pattern of triploid M. laterali was similar to that of diploids, but it also showed characteristics such as developmental retardation, few mature gametes, and gamete gigantism. The dynamic expression of genes related to gonadal development provided further molecular evidence for this phenomenon. Additionally, 82.6% of triploid M. laterali exhibited normal spawning behavior, produced fewer but larger viable gametes, and could generate offspring with full developmental potential. Flow cytometry analysis revealed that sperm of triploid M. laterali was aneuploid, with a DNA content of about 1.5 times that of diploid sperm, and the ploidy levels of mating offspring were 2N (DD, diploid female × diploid male), 2.5N (DT, diploid female × triploid male), 2.5N (TD, triploid female × diploid male), and 3N (TT, triploid female × triploid male), respectively. Overall, the artificially induced triploid M. laterali has been confirmed to be bisexually fertile, which will provide a unique model for exploring the underlying mechanisms of advantageous trait formation and fertility regulation in triploids, and offer a valuable platform for the study of ploidy control and polyploidization in bivalves. Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary. Yes, i have checked and it is OK.

Spotted knifejaw (Oplegnathus punctatus) is an economically important marine cultured species exhibiting a unique complex sex chromosome system (X₁X₁X₂X₂ in females and X₁X₂Y in males), with males possessing one fewer chromosome (2n = 47) than females (2n = 48) and an abnormally large Y chromosome. Additionally, males demonstrate significant growth advantages over females. Rapid and accurate sex identification is essential for effective culture management, selective breeding, and population control. In this study, we identified a homologous region of the tmem88 gene containing large DNA insertion markers on the X and Y chromosomes through whole-genome sequencing of O. punctatus. The X₁ chromosome harbors a 278 bp DNA fragment, whereas the Y chromosome contains a 1472 bp fragment, resulting in a 1194 bp size difference indicative of structural variation in the non-coding region of the tmem88 gene. We developed a rapid detection method based on this variation, utilizing a pair of primers that amplify two distinct bands (278 bp and 1472 bp) in male (X₁X₂Y) individuals and a single 278 bp band in female (X₁X₁X₂X₂) individuals when analyzed by agarose gel electrophoresis. This method enables efficient and accurate sex differentiation in O. punctatus, significantly reducing the time required for identification and enhancing detection efficiency. This study provides a valuable tool for the rapid identification of sex in O. punctatus, facilitating improved breeding strategies and supporting the large-scale production of high-quality fry.

Galectins exhibit a variety of biological functions through interactions with their ligands, including galactose and its derivatives. Tandem-repeat galectins, such as Galectin-8, can act as pattern recognition receptors to aggregate and neutralize bacterial pathogens. In this study, Galectin-8 was identified in Trachinotus ovatus (golden pompano). Galectin-8 consists of two carbohydrate recognition domains (CRDs) connected by a linker region. Furthermore, molecular docking analysis suggests that the C-terminal CRD can bind galactose, mannose, and N-acetylglucosamine at similar binding sites. ToGal-8 expression levels were highest in the brain and blood of healthy T. ovatus. However, following infection with Streptococcus agalactiae, expression levels in the spleen and head kidney surged at 48 h, while liver expression significantly decreased by 96 h. Cytoplasmic Galectin-8 expression was upregulated after stimulation by peptidoglycan compared with lipopolysaccharide. Recombinant ToGal-8 (rToGal-8) was produced using a prokaryotic expression system. This protein could agglutinate red blood cells from rabbits, carp, and T. ovatus independently of Ca²⁺. Moreover, it was also effective in aggregating and eliminating several bacterial strains, such as Staphylococcus aureus, Bacillus subtilis, Vibrio vulnificus, S. agalactiae, Pseudomonas aeruginosa, and Aeromonas hydrophila. Therefore, this study provides an in-depth analysis of the function of T. ovatus Galectin-8 for the first time, offering guidance for the healthy aquaculture of T. ovatus.

In recent years, CRISPR/Cas9 gene editing technology has emerged as a powerful genetic tool with potential application in aquaculture. Crassostrea gigas, as a valuable species in aquaculture, holds promising potential for genetic enhancement and breeding through gene editing. However, the lack of efficient promoters for driving exogenous gene expression poses a major obstacle in bivalve gene editing. In this study, we isolated the promoter sequences of the β-tub and histone H3.3A genes from C. gigas. DNA expression constructs were generated by linking the promoters with the enhanced green fluorescent protein (EGFP) reporter and compared with the promoter activity of the endogenous EF-1α gene and an exogenous OsHV-1 promoter in C. gigas embryos. All four promoters effectively drive the expression of EGFP during early embryonic development in C. gigas. Among these four promoters, the β-tub promoter is the most potent promoter in driving EGFP expression in C. gigas embryos as early as 4.5 h after fertilization. The OsHV-1 promoter showed similar activity as β-tub promoter and appeared to be more active than the EF-1α and histone H3.3A promoters in C. gigas embryos. Furthermore, we assessed their performance in other three C. gigas relatives (Crassostrea ariakensis, Crassostrea nippona, and Crassostrea sikamea) and similar results were found. Collectively, these data suggest that the β-tub promoter is an effective promoter in directing gene expression in directing gene expression in oyster embryos, thus offering a potential application for gene editing in bivalves.

Plastic pollution through the leaching of di(2-ethylhexyl) phthalate (DEHP), a widely used plasticizer, has led to the emergence of mangrove pollution. This study aimed to assess the DEHP removal efficiency of indigenous mangrove sediment microbiomes and identify key DEHP degraders using microcosm construction and metagenomic analysis. During the 35-day incubation period, the indigenous mangrove sediment microbiome, affected by chronic plastic pollution, demonstrated a 99% degradation efficiency of 200 mg/kg DEHP. Spearman’s correlation analysis suggested that Myxococcales, Methyloligellaceae, Mycobacterium, and Micromonospora were potentially responsible for DEHP degradation. Based on PICRUSt2, the DEHP-degrading pathway in the sediment was predicted to be an anaerobic process involving catechol metabolism through catC, pcaD, pcaI, pcaF, and fadA. Efficient bacterial isolates from the mangrove sediment, identified as Gordonia sp. and Gordonia polyisoprenivorans, were able to degrade DEHP (65–97%) within 7 days and showed the ability to degrade other phthalate esters (PAEs).

Allometric growth is a typical characteristic of crustaceans, which mainly occurs among individuals, life stages, tissues, and between sexes. The red swamp crayfish Procambarus clarkii is an economically important crustacean species in the world. To date, the molecular regulatory mechanisms of neuroendocrine system in the allometric growth of P. clarkii remain unclear. In this study, P. clarkii exhibiting significant allometric growth among individuals were sampled from three full-sibling families. The brain, eyestalk, nerve cord, and Y-organ were dissected for transcriptome analysis. Key functional genes were identified by random forest and DESeq2 methods. The gene pathways were enriched utilizing Kyoto Encyclopedia Genes and Genomes (KEGG) analysis. Gene topological analysis was established through weighted gene co-expression network analysis (WGCNA), and hub genes were screened by protein–protein interaction (PPI) networks. Transcriptomic analysis results were validated via qRT-PCR. RNA-Seq identified 31 differentially expressed genes (DEGs) (7 up- and 24 downregulated); 301 DEGs (23 up- and 278 downregulated); 1308 DEGs (474 up- and 834 downregulated); and 64 DEGs (52 up- and 12 downregulated) in the brain, eyestalk, Y-organ, and nerve cord, respectively. Crucial functional genes such as CHIA in the brain and perlucin-like in the eyestalk were notably identified. WGCNA revealed two hub modules, while PPI networks identified neuroendocrine regulators module which hub genes mainly including CP1876-like and cuticle protein AM1199-like, and structural components module which hub genes mainly including CUB& CCP Domain-Containing Protein, ARRDC, and E3 Ubiquitin protein ligase MCYCBP2-like. Correspondingly, the significant gene pathways such as amino sugar and nucleotide sugar metabolism (pcla00520) and insect hormone biosynthesis (pcla00981) were enriched. The results revealed the complex interactions and regulatory relationships of hub genes within hub modules to coordinate molting and growth. The results of RNA-Seq analysis were validated by the consistency of gene expression in qRT-PCR. In present study, key functional genes in the neuroendocrine system regulating allometric growth among individuals were identified, and significant pathways mainly include hormone synthesis were screened, thus constructing a neuroendocrine molecular regulatory network for the allometric growth of P. clarkii. Building on these investigations, a comprehensive mechanism whereby neuroendocrine regulators interact with structural components to coordinate molting and growth was proposed. The result would provide valuable insights into the molecular regulatory mechanisms of allometric growth, highlighting the interplay between the neuroendocrine system and relevant tissues.