摘要: Few studies have reported obtaining grass carp resistant to hemorrhagic disease via gene editing in commercial fish. Here, we demonstrate that the expression and activity of grass carp PI4KB (gcPI4KB) are vital for GCRV-I and GCRV-II replication. Given the obvious cytopathic effect (CPE) in the present available cell lines is only caused by GCRV-I, but GCRV-II is the current popular and fatal strain in grass carp, GCRV-I and GCRV-II are used in cell lines and in grass carp, respectively. In vitro studies in CIK cells revealed that gcPI4KB interacted with NS80 and VP3 of GCRV-I, and that gcPI4KB was recruited by NS80 for promoting the generation of GCRV viral inclusion bodies (VIBs). Since the negative regulatory role of gcPI4KB in GCRV infection was confirmed by in vitro data, we performed gene editing of gcPI4KB in grass carp. We found that PI4KB F0 juvenile grass carp crispants have obvious advantages in promoting growth and in resisting GCRV-II infection. Compared with uninfected WT grass carp, the uninfected PI4KB F0 juvenile grass carp crispants exhibit a higher expression level of many genes involved in growth- and development-related metabolic pathways such as the FoxO signaling pathway and insulin signaling pathway. Compared with WT grass carp without infection, PI4KB F0 juvenile grass carp crispants without infection or WT grass carp infected with GCRV-II, higher expression levels for many genes involved in metabolic diseases and viral infections were observed in the liver from PI4KB F0 juvenile grass carp crispants infected with GCRV-II. Altogether, the present study suggests the mechanism of gcPI4KB in facilitating GCRV replication, the signaling pathways regulated by gcPI4KB, and the possibility to obtain grass carp resistant to hemorrhagic disease via gene editing of PI4KB.

摘要: Ciliated microeukaryotes (ciliates) are distinguished by their cilia, which are rich in tubulin. We developed a method for tubulin staining in ciliate cells that involves using live-cell tubulin-staining dyes instead of antibodies thereby streamlining the staining process, which is effective across diverse ciliate lineages. Moreover, our method allows integration with immuno fluorescence staining using antibodies when needed. The potential applications of this technique extend to cell biology and ciliate morphological and ecological studies.

摘要: The hypoxia-inducible factor (HIF)-mediated hypoxia signaling pathway influences oxygen homeostasis in aerobic organisms. This pathway is regulated by several other pathways. Elucidation of its regulation and the underlying mechanisms may provide insights into the strategies of adaptation and tolerance of organisms to hypoxia. In this study, we found that loss of ubiquitin-specific protease 3 (usp3) in zebrafish promotes hypoxia tolerance. Zebrafish usp3 specifically binds to hif-1 alpha a and induces its proteasomal degradation, which is dependent on its deubiquitinase activity. This process leads to the suppression of hypoxia signaling under hypoxia. In addition, usp3 catalyzes the deubiquitination of K63-polyubiquitinated hif-1 alpha a. Endogenous evidence indicated that mammalian USP3 behaves like zebrafish usp3 in regulating the activity of HIF-1 alpha. These findings revealed a novel role for usp3 in influencing hypoxia signaling and showed that usp3-mediated HIF-1 alpha degradation impairs hypoxia signaling, leading to a decrease in hypoxia tolerance.

摘要: Biologging is a method that utilizes animal-borne devices to study the behavioural ecology, physiology, and surrounding environment of animals. This is the Lagrangian observation method, which assigns a coordinate system origin to each animal, making the biologging unique among observation platforms. This study reviews biologging as a new tool for understanding the ocean by combining other observation methods, and proposes strategies for applying biologging technology to address various marine issues through relevant policies. Attempts to resolve marine issues using biologging are described, including ocean warming, weather forecasting, marine debris, marine chemical pollution, anthropogenic noise, preservation of marine protected areas, bycatch from fisheries, and anthropogenic disturbance of habitats used by marine top predators. While biologging alone is insufficient to resolve marine issues, it can complement other Lagrangian platforms such as drifting buoys and Eulerian remote sensing, enhancing the predictive accuracy of models, and filling existing gaps in knowledge. The Internet of Animals (IoA), which is a derivative concept of the Internet of Things (IoT), will be a future solution that collects a range of data from inaccessible ocean from animals equipped with devices through a network, making open data access crucial. Conclusively, we present research examples and potential methods involving biologging that will guide the formulation of sustainable ocean management policies.

摘要: Aquaculture, as a major source of protein in the food industry, heavily relies on the introduction and farming of non-native species. Pikeperch, Sander lucioperca, an important fish in aquaculture, poses a threat to the survival of native species because it is a piscivore and has been introduced globally. To address this issue, we examined the niche dynamics of invasive populations by comparing the climatic niches of native and invasive populations of Pikeperch. Predictive models based on global occurrence data were used to assess the distribution areas of native and invasive populations, and the model results were converted into area measurements to estimate the potential invasion risk of pikeperch. The results show that invasive populations, especially those in Asia, occupy broader climatic niches. The main difference is that, compared to native-range populations, non-natives occupy warmer and more humid regions. These climatic differences have led to niche expansion by invasive populations, with invasive populations (particularly in Asia) showing a greater potential for invasion. we applied niche modeling to evaluate the potential invasion risks associated with introducing different geographic populations. Our models provide a scientific basis for managing aquaculture introductions, aiming to reduce invasion risks and minimiz both ecological and economic impacts.

摘要: Identifying precise egg attachment areas and tracking trends of spawning magnitude (total amount of spawned eggs) are critical for accurate habitat assessment and effective conservation efforts, especially for lithophilic spawning fishes. However, accurate measurement of spawning conditions across both spatial and temporal dimensions poses significant challenges. We conducted a fourteen-year field study below the Gezhouba Dam, the main spawning ground for the Chinese sturgeon, using Kernel Density Estimation (KDE) method and Catch per Unit of Effort (CPUE) to refine knowledge on egg attachment areas relative to previous assessments. In addition, our analysis documented shifts in spawning locations within these four areas over the past fourteen years, revealing a worrying trend of decreasing spawning magnitude. This approach not only enabled the incorporation of the density distribution of eggs into the assessment of spawning magnitude trends, but also underscored the potential of the KDE as a framework for identifying egg attachment areas and estimating spawning magnitude trends. Our results provide valuable insights into spawning degradation of Chinese sturgeon and inform conservation strategies to protect their fragile spawning grounds.

摘要: Maternal immunity plays a vital role in protecting offspring from pathogen invasion, and it is present in nearly all vertebrates. As the most ancient vertebrates, teleost fish continuously secrete a substantial amount of mucus due to their unique living environment, and often exhibit schooling behavior. Previous studies have highlighted the presence of numerous immune components in the mucus of fish, that plays a crucial role in resisting pathogens. We hypothesize that this represents a distinctive maternal immune response mechanism in fish. In this study, we established a dextran sulfate sodium (DSS)-induced injury model by immersing zebrafish larvae in 0.5% DSS. This elicited robust infiammatory responses and showed DSS-induced alterations in microbial abundance via 16S rRNA sequencing. These changes included the disruption of normal gut structure; an increase in goblet cells; increased expression of infiammatory cytokines; and infiltration of neutrophils and macrophages into the gut, as well as an increase in pathogenic bacteria and a decline in probiotic bacteria. Furthermore, we conducted a mucus protection test by adding adult zebrafish mucus in fish tank water containing 0.5% DSS to test our hypothesis. As suspected, the mucus from adult zebrafish exhibited a protective role in defending zebrafish larvae against DSSinduced enteritis by alleviating excessive infiammatory responses and increasing probiotic abundance. In conclusion, our results confirm a significant role of adult fish mucus in the immune response of teleost fish to DSSinduced infiammation. Collectively, our findings show that the mucus of adult zebrafish may represent a novel form of maternal immunization, playing roles analogous to mammalian milk in immune regulatory functions.

摘要: Aggregation is suggested beneficial with foraging, defense, and other fitness for the group members. While long distance dispersal with kinship has been found in several marine fishes, similar cases have not been reported in inland waters. We utilized microsatellite genotype data of 397 eggs or juvenile silver carp (Hypophthalmichthys molitrix) born in 2017 from the middle and lower reaches of the Yangtze River in China to analyze their relatedness and infer the dispersal patterns during their early life stages and whether they dispersed with their kinship. There were 11-58 pairs of full siblings or half siblings between samples from the spawning ground (Yichang section) and other sites (34.1-1047.2 km) which showed the dispersal path. Particularly, the proportion of maternal siblings (mean: 47.9%) was higher than random, indicating kinship aggregation, or that the fish traveled with their kinship during their early life stages. Such kin aggregation has profound implications for our understanding of early life stage dispersal in inland water fish populations. Our findings suggest that the preservation of habitats along the middle Yangtze River should be increased. In particular, the channelized river bank should be rebuilt with more heterogeneous habitat, and the lake-river connections should be restored to expand the amount of appropriate habitat.

摘要: Recent cold waves and abrupt seasonal temperature drops have significantly impacted aquaculture, slowing fish growth and causing mass mortality. The intestine plays a crucial role in digestion, nutrient absorption, metabolism, and physiological regulation. However, studies on the molecular mechanisms of fish intestinal response to low-temperature stress and methods to mitigate damage are limited. This study investigated the intestinal response of Danio rerio to low temperatures with three groups: a control group at 28 degrees C (CT28), a cryogenic group at 18 degrees C (ST18), and an extreme cryogenic group at 10 degrees C (LT10), with time points of 0, 12, 24, and 48 h. Results showed significant structural changes in the 18 degrees C group, with inflammatory infiltration starting at 24 h. Damage worsened in the 10 degrees C group, showing severe inflammation. Tunel staining revealed increased cell apoptosis with lower temperatures and longer exposure, peaking at 10 degrees C and 48 h following exposure (p < 0.05). Alcian blue periodic acid-schiff stain revealed that lower temperatures promote an increase in the number of goblet cells. Metabolomics analysis compared intestinal metabolites between CT28 vs. ST18 and CT28 vs. LT10. Fifty-three metabolites were shared between the CT28_ST18 and CT28_LT10 groups in positive ion mode, and 16 in negative mode, with 22 and 9 metabolites showing linear changes. These 31 metabolites could serve as potential indicators for low-temperature stress in D. rerio. Specifically, eight metabolites from the lysophosphatidylcholine (LPC) group increased significantly, while antioxidant alanylglutamine (AGD) decreased. Supplementing the diet with 0.5% AGD reduced intestinal damage, and 1.0% AGD improved low-temperature tolerance. This study provides new insights into the molecular mechanisms of fish response to cold stress and lays the foundation for future research.

摘要: The genus Neophocaena includes two species, the Indo-Pacific finless porpoise (N. phocaenoides) and the Narrowridged finless porpoise (N. asiaeorientalis). The Indo-Pacific species is found in coastal waters from the Persian Gulf through south and southeast Asia to as far north as the Taiwan Strait. The Narrow-ridged finless porpoise ranges from the Taiwan Strait to the waters of northern China, Korea, and Japan. Within N. asiaeorientalis there are two subspecies, the Yangtze finless porpoise (N. a. asiaeorientalis), found in the Yangtze River and adjoining lakes in China, and the East Asian finless porpoise (N. a. sunameri), found in coastal marine waters of China (including Hong Kong and Taiwan), Korea, and Japan. In 2019, an international workshop was held on finless porpoise research and conservation. Participants shared that, in many regions, information on distribution, abundance and population structure is lacking or inadequate. A global assessment of research is critical to provide a basis for conservation planning. Anthropogenic activities (i.e., habitat degradation, pollution, etc.) are known threats, with fisheries bycatch the primary threat throughout the known distribution of finless porpoises. To conserve these cetaceans, research priorities include studies of abundance and distribution, habitat and ecology, fisheries-related mortality, increased public awareness, and bycatch mitigation.