摘要: Fish, which are vital for both aquatic ecosystem functionality and global food supply, rely heavily on their gastrointestinal tract (GIT) microbiota for the digestion that underpins their growth and health. Takifugu pufferfish, which are an example of species evolved through adaptive radiation, possess a GIT that is specialized for antipredator defense and gluttonous feeding behaviors, offering a unique model to explore the effects of GIT compartmentalization and host genetics on gut microbial communities. Here we compiled 78 full and partiallength 16 S rRNA amplicon datasets across three anteroposteriorly distinct intestinal sites in a cohort of cohabitating artificial hybrid and purebred Takifugu pufferfishes. Our findings reveal a compositional and functional biogeography of pufferfish gut microbiota along the GIT and between host genetics. Additionally, the differential abundance of specific amplicon sequence variants and their correlation with host genetic backgrounds and intestinal sections highlight the role of environmental filtering in shaping microbial communities, with certain bacterial taxa exhibiting strong preferences for particular intestinal sites or genetic backgrounds, suggesting potential localized adaptation or functional specialization. This study enhances our understanding of the intricate interplay between host genetics, gut anatomy, and microbiota in fish, underscoring the importance of detailed microbial profiling in conservation efforts and aquaculture practices, and emphasizing the necessity of integrating full-length 16 S rRNA sequencing with partial-length datasets to comprehensively understand microbial diversity and function, paving the way for improved fish health management and sustainable aquaculture strategies.

摘要: To investigate the effect of oxidized fish oil on fish muscle metabolic responses and flesh quality, Nile tilapia (Oreochromis niloticus) weighing 13.73 f 0.31 g were fed two diets for 12 weeks: a fresh fish oil (FFO) and a highly oxidized fish oil (OFO) diet. The peroxide value of the FFO and OFO diets was 2.2 meq/kg and 120.6 meq/kg, respectively. The OFO diet resulted in a decrease in growth, muscularity, nutritional value of fatty acids in the muscle, and density of myofibers. In the OFO group, the mRNA expression levels of lipolysis genes including lipoprotein lipase (lpl) and hormone-sensitive lipase (hsl) in the muscle were upregulated compared with the FFO group, while, the mRNA expression level of acetyl CoA carboxylase was downregulated. Additionally, under the positive ion mode, the levels of DHA deposition in phosphatidylcholine and phosphatidyl ethanolamine were reduced in the muscle of the OFO group compared to the FFO group. A total of 68 proteins were identified in the muscle, of which 42 were up-regulated and 26 were down-regulated. The KEGG pathway enrichment analysis revealed that the major pathways of the differentially abundant proteins were the Wnt signaling pathway, TGF-beta signaling pathway, and proteoglycans in cancer. In summary, the OFO diet negatively affected growth, muscularity, and nutritional value. It also inhibited the transformation of myofiber types and led to the apoptosis of myofibers.

摘要: Phosphorus is a plant nutrient that is the main driving force of eutrophication, a serious type of water pollution. Various techniques and materials have been used to identify cost-effective, environmentally friendly options for phosphate removal. Eggshell waste is a good natural source of calcium, which is an effective adsorbent for phosphate removal. Many studies have examined pure eggshell, eggshell chemically modified with metal salts, and calcined eggshell mixed with biochar for phosphate removal. Here, most research on eggshell-based phosphate removal is reviewed to clarify the effectiveness of different types of modifications. Adsorption isotherm and kinetics models are the best methods for identifying the mechanism of adsorption, and both pure and modified eggshell have been characterized to understand the morphological and structural changes after adsorption. Furthermore, the phosphate-loaded material could be used as a fertilizer if it is not modified with harmful or toxic material. Eggshell-based adsorbents may provide cheaper, ecofriendly adsorbents for phosphate removal.

摘要: Animals exhibit remarkable behavioral and molecular adaptations to cope with thermal stressors, which are crucial for survival in variable environments that are exacerbated by climate change. Aquatic poikilotherms like our model organism-the pond snail Lymnaea stagnalis-face significant challenges due to their dependence on external temperatures. Our study provides valuable insights into the different behavioral and molecular responses of lab-inbred snails to cold and heat shock stressors (i.e., 4 degrees C and 30 degrees C), particularly in the context of learning and memory formation. We found that while short-term (1 h) cold exposure transiently upregulated the expression levels of HSP70 and HSP40 in the snail's central ring ganglia, prolonged cold exposure (24 h) resulted in a significant downregulation of LymMIPII and an upregulation of LymMIPR. These data suggest, albeit at the transcriptional level, the existence of a negative feedback loop necessary for sustaining cellular functions when metabolic demands might shift towards conserving energy during prolonged cold exposure. At the behavioral level, we found that, compared to heat shock, cold exposure did not result in a Garcia effect (i.e., a special form of conditioned taste aversion). The difference in memory outcomes was associated with changes in the expression levels of selected targets involved in neuronal plasticity and the stress response. While both cold and heat shock upregulated the HSP levels in the snail's central ring ganglia, cold exposure did not affect the expression levels of the neuroplasticity genes LymGRIN1 and LymCREB1, contrasting with heat shock's neurogenic effects. Overall, this study provides insights into L. stagnalis's adaptive responses to thermal stressors, emphasizing different molecular strategies for coping with heat versus cold challenges in aquatic environments. These findings contribute to our understanding of thermal biology and stress physiology in aquatic organisms, underscoring the importance of molecular mechanisms in shaping species'resilience in dynamic environments.

摘要: The Really Interesting New Gene (RING) ubiquitin E3 ligase family comprises a large number of members and plays a crucial role in the antiviral process. RING finger protein 115 (RNF115), also known as BCA2, Rabring7, or ZNF364, is a novel RING domain protein. In this paper, we cloned the RNF115 homologue from black carp (Mylopharyngodon piceus) and characterized it. The open reading frame of black carp RNF115 contains 933 nucleotides and encodes 310 amino acids. The C-terminal RING domain of RNF115 is highly conserved among various homologous species. Immunofluorescence assays revealed the cytoplasmic and nuclear distribution of RNF115 in the presence or absence of spring viremia of carp virus (SVCV) infection. Overexpression of RNF115 impaired interferon (IFN) and the related interferon-stimulated gene (ISG) mRNA expression, while upregulating SVCV replication. Ex vivo knockdown of RNF115 offered the host cells enhanced antiviral signaling. In vivo knockdown of RNF115 also strengthened black carp's antiviral capacity. Additionally, the results of a dualluciferase reporter assay, plaque assay, and qRT-PCR assay demonstrated that co-transfection of RNF115 with IRF3/7 reduced IRF3/7-induced IFN transcription and antiviral ability. The association between RNF115 and IRF3/7 was detected by co-immunoprecipitation and immunofluorescence assays. Co-transfection of RNF115 with IRF3/7 also reduced the protein levels of IRF3/7, which were rescued by MG132. The enhanced K48-linked ubiquitination of IRF3/7 under the condition of RNF115 co-transfection implied the ubiquitin/proteasome degradation pathway catalyzed by RNF115. Cysteine 238 and 241 in the RING domain are the main enzyme active sites for RNF115, and the mutant C238/241A lost most of its ability to restrict IRF3/7. In conclusion, black carp RNF115 dampens IRF3/7-mediated IFN signaling through facilitating the ubiquitination and degradation of IRF3/7, which sheds light on the regulation of IFN signaling.

摘要: In this study, we recorded the noise radiating from a wind farm and evaluated its potential impact on the fishes and Indo-Pacific humpback dolphins (Sousa chinensis) residing in the Pearl River Estuary. The pile driving pulses, recorded 30 m from the construction site, had a mean zero-to-peak sound pressure level of 195.1 dB (re 1 mu Pa) (n 1/4 238), exceeding the hearing thresholds of both fishes and Indo-Pacific humpback dolphins. The operational noise from the wind farm was significantly lower in amplitude; therefore, our analysis primarily focused on the radiation of pile driving noise. Acoustic measurements taken at three different distances during pile driving events supported the development of an acoustic propagation model, which was then used to predict the sound exposure levels of pile driving pulses radiating from 5 m below the water surface. By referring to established noise exposure metrics, we estimated an impact zone of 12.8 m for fishes. For the Indo-Pacific humpback dolphins, the permanent and temporary threshold shift zones were predicted to be 32.4 m and 580.9 m, respectively. Our findings underscore the importance of increasing our understanding on hearing sensitivities of the local inhabitants in the Pearl River Estuary and identify their core habitats. This approach enabled us to use the model to estimate impact zones and better protect the local marine life from the effects of pile driving noise radiation.