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18 pages, 4468 KiB

Open AccessArticle

Proteomic and Functional Analysis Reveals Temperature-Driven Immune Evasion Strategies of Streptococcus iniae in Yellowfin Seabream (Acanthopagrus latus)

by Yanjian Yang, Guanrong Zhang, Ruilong Xu, Yiyang Deng, Zequan Mo, Yanwei Li and Xueming Dan

Biology 2025, 14(8), 986; https://doi.org/10.3390/biology14080986 (registering DOI) - 2 Aug 2025

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Abstract

Streptococcus iniae (S. iniae) is a globally significant aquatic pathogen responsible for severe economic losses in aquaculture. While the S. iniae infection often exhibits distinct seasonal patterns strongly correlated with water temperature, there is limited knowledge regarding the temperature-dependent immune evasion [...] Read more.

Streptococcus iniae (S. iniae) is a globally significant aquatic pathogen responsible for severe economic losses in aquaculture. While the S. iniae infection often exhibits distinct seasonal patterns strongly correlated with water temperature, there is limited knowledge regarding the temperature-dependent immune evasion strategies of S. iniae. Our results demonstrated a striking temperature-dependent virulence phenotype, with significantly higher A. latus mortality rates observed at high temperature (HT, 33 °C) compared to low temperature (LT, 23 °C). Proteomic analysis revealed temperature-dependent upregulation of key virulence factors, including streptolysin S-related proteins (SagG, SagH), antioxidant-related proteins (SodA), and multiple capsular polysaccharide (cps) synthesis proteins (cpsD, cpsH, cpsL, cpsY). Flow cytometry analysis showed that HT infection significantly reduced the percentage of lymphocyte and myeloid cell populations in the head kidney leukocytes of A. latus, which was associated with elevated caspase-3/7 expression and increased apoptosis. In addition, HT infection significantly inhibited the release of reactive oxygen species (ROS) but not nitric oxide (NO) production. Using S. iniae cps-deficient mutant, Δcps, we demonstrated that the cps is essential for temperature-dependent phagocytosis resistance in S. iniae, as phagocytic activity against Δcps remained unchanged across temperatures, while NS-1 showed significantly reduced uptake at HT. These findings provide new insights into the immune evasion of S. iniae under thermal regulation, deepening our understanding of the thermal adaptation of aquatic bacterial pathogens. Full article

(This article belongs to the Special Issue Aquatic Economic Animal Breeding and Healthy Farming)

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16 pages, 4761 KiB

Open AccessArticle

Metabolic Alterations in Crassostrea Gigas After Feeding Selenium-Enriched Yeast Based on Transcriptomic Analysis

by Yancheng Zhao, Xiaojing Jiang, Liming Jiang, Yongjie Wang, Cuiju Cui, Xiumei Liu, Zan Li, Weijun Wang and Jianmin Yang

Biology 2025, 14(7), 898; https://doi.org/10.3390/biology14070898 - 21 Jul 2025

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Abstract

This study explores the effects of selenium-enriched yeast supplementation on growth-related and immune-related gene expression in C. gigas, aiming to support feed optimization in oyster aquaculture. Selenium, an essential trace element, is vital for growth, immune function, and metabolism in animals. Selenium-enriched [...] Read more.

This study explores the effects of selenium-enriched yeast supplementation on growth-related and immune-related gene expression in C. gigas, aiming to support feed optimization in oyster aquaculture. Selenium, an essential trace element, is vital for growth, immune function, and metabolism in animals. Selenium-enriched yeast, an organic form, offers superior bioavailability, enabling efficient absorption and utilization. C. gigas, a commercially significant marine shellfish, is rich in protein and nutrients, but the effects of selenium on mollusks remain insufficiently explored. In this study, oysters were divided into three groups: a control group without selenium (THNP), a 2 ppm selenium group (THMP), and a 4 ppm selenium group (THHP). Transcriptome sequencing yielded 388,679,026 clean reads. GO and KEGG enrichment analyses identified key metabolic signaling pathways, and a PPI analysis was performed on the translation products of DEGs involved in the KEGG pathways. qRT-PCR validated the expression of principal DEGs. The combined results of enrichment and PPI analyses highlighted pathways such as glutathione metabolism and collagen signaling. Additionally, three hub genes—FASN, HRAS, and ABCG5—were identified as central to the selenium response. These findings enhance the understanding of selenium’s molecular impact on oysters and support its application in aquaculture. Full article

(This article belongs to the Special Issue Aquatic Economic Animal Breeding and Healthy Farming)

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20 pages, 16304 KiB

Open AccessArticle

Functional Analysis of the Cyclin E Gene in the Reproductive Development of Rainbow Trout (Oncorhynchus mykiss)

by Enhui Liu, Haixia Song, Wei Gu, Gaochao Wang, Peng Fan, Kaibo Ge, Yunchao Sun, Datian Li, Gefeng Xu and Tianqing Huang

Biology 2025, 14(7), 862; https://doi.org/10.3390/biology14070862 - 16 Jul 2025

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Abstract

As a commercially valuable aquaculture species, rainbow trout (Oncorhynchus mykiss) urgently require solutions to growth inhibition associated with reproductive development. To elucidate the function of the cell cycle regulator Cyclin E genes (CCNE1 and CCNE2) in this process, we [...] Read more.

As a commercially valuable aquaculture species, rainbow trout (Oncorhynchus mykiss) urgently require solutions to growth inhibition associated with reproductive development. To elucidate the function of the cell cycle regulator Cyclin E genes (CCNE1 and CCNE2) in this process, we cloned the genes and analyzed their relative expression across various tissues and gonadal developmental stages. Using RNA interference (RNAi) and overexpression in RTG2 cells, we examined the effects of CCNE on cell viability, proliferation, and meiotic gene expression. Results showed that the open reading frame lengths of CCNE1 and CCNE2 were 1230 bp and 1188 bp, encoding 408 and 395 amino acids, respectively. Both proteins contain two conserved cyclin boxes, exhibit high structural similarity, and are phylogenetically most closely related to Oncorhynchus tshawytscha and Oncorhynchus kisutch. Expression and localization analyses revealed that CCNE1 was highly expressed in the ovary, while CCNE2 was highly expressed in the testis. Both proteins were expressed during fertilized egg development and key gonadal stages (at 13, 21, and 35 months post-fertilization). CCNE expression positively correlated with RTG2 cell viability and proliferation, with immunofluorescence confirming that CCNE is localized in the nucleus. Knockdown or overexpression of CCNE induced the differential expression of reproductive-related genes and key meiotic regulators. These findings suggest that CCNE1 and CCNE2 balance meiosis and gamete development through specific regulatory mechanisms, and their dysregulation may be a key factor underlying meiosis inhibition and reproductive development abnormalities. Full article

(This article belongs to the Special Issue Aquatic Economic Animal Breeding and Healthy Farming)

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15 pages, 4461 KiB

Open AccessArticle

Turmeric Oil Interferes with Quorum Sensing as an Alternative Approach to Control Aeromonas hydrophila Infection in Aquaculture

by Jing Dong, Jian Tong, Shengping Li, Xinwei Ma, Qiuhong Yang, Yongtao Liu, Shun Zhou, Xizhi Shi and Xiaohui Ai

Biology 2025, 14(5), 483; https://doi.org/10.3390/biology14050483 - 27 Apr 2025

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Abstract

Aquatic products play a crucial role in meeting the increasing global demands for high-quality proteins. However, the occurrence of bacterial diseases results in significant economic losses worldwide. Aeromonas hydrophila (A. hydrophila) is the pathogen of several fish diseases. Antibiotics were widely [...] Read more.

Aquatic products play a crucial role in meeting the increasing global demands for high-quality proteins. However, the occurrence of bacterial diseases results in significant economic losses worldwide. Aeromonas hydrophila (A. hydrophila) is the pathogen of several fish diseases. Antibiotics were widely used in combating bacterial diseases in aquaculture. The increasing occurrences of antibiotic resistance necessitate the restricted use of antibiotics. Consequently, developing drugs that avoid antibiotic resistance is important for the future of aquaculture. Quorum sensing (QS) is critical for bacterial pathogens in regulating bacterial virulence and is a promising target for developing anti-infective agents. Here, we found that turmeric oil with a MIC of 256 μg/mL could dose-dependently reduce the virulence phenotypes regulated by QS, ranging from 8 to 64 μg/mL, suggesting that sub-inhibitory concentrations of turmeric oil could inhibit bacterial virulence. Further qPCR findings demonstrated that turmeric oil could significantly inhibit the transcription of aerA, ahyI, and ahyR by a 54-fold, 36-fold, and 56-fold change reduction, respectively. Cell live/dead staining and animal study results showed that turmeric oil could inhibit the pathogenicity of A. hydrophila. Fish treated with turmeric oil showed a reduced mortality rate of 60%, whereas all fish in the positive control group died. Moreover, treatment with turmeric oil could alleviate the renal injury. Collectively, the results suggested that targeting bacterial virulence might be a useful approach to combating bacterial infections, and turmeric oil could serve as a potential agent for combating A. hydrophila infections. Full article

(This article belongs to the Special Issue Aquatic Economic Animal Breeding and Healthy Farming)

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15 pages, 1510 KiB

Open AccessArticle

Two Demosponges as Promising Bioremediators of a Potential Pathogenic Vibrio

by Joseba Aguilo-Arce, Maria Scrascia, Roberta Trani, Carlo Pazzani, Pere Ferriol and Caterina Longo

Biology 2025, 14(2), 140; https://doi.org/10.3390/biology14020140 - 29 Jan 2025

Cited by 1 | Viewed by 1041

Abstract

With more than 9600 valid species worldwide [...] Full article

(This article belongs to the Special Issue Aquatic Economic Animal Breeding and Healthy Farming)

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15 pages, 4906 KiB

Open AccessArticle

Comparative Analysis of Intestinal Microbiota in Wild, Domesticated, and Cultured Gymnocypris potanini firmispinatus

by Baoshan Ma, Jiaqi Zhang, Dapeng Li, Zhipeng Chu, Jieya Liu, Jiali Jin and Liqiao Zhong

Biology 2024, 13(12), 983; https://doi.org/10.3390/biology13120983 - 28 Nov 2024

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Abstract

The impact of the living environments on the intestinal microbiota of Gymnocypris potanini firmispinatus was studied by analyzing intestinal microbiota diversity, composition, and potential function among wild, domesticated, and cultured groups. The results showed that the fish living in the wild environment exhibited [...] Read more.

The impact of the living environments on the intestinal microbiota of Gymnocypris potanini firmispinatus was studied by analyzing intestinal microbiota diversity, composition, and potential function among wild, domesticated, and cultured groups. The results showed that the fish living in the wild environment exhibited the highest alpha diversity of intestinal microbiota. Intestinal microbial communities in the three groups clustered by living environment, with domesticated and cultured groups showing higher similarity. The dominant phylum in the wild group was Proteobacteria, whereas Fusobacteria and Proteobacteria were the predominate bacteria in the domesticated and cultured groups. RsaHF231, Actinobacteria, Fusobacteria, Cyanobacteria, and Firmicutes were the five key bacteria differentially expressed among the groups. Functional prediction revealed significant variation in the L-cysteine degradation III pathway (PWY-5329) between wild and domesticated groups, and in the vitamin E biosynthesis pathway (PWY-1422) between wild and cultured groups (p < 0.05). These findings highlight the differences in microbiota communities between wild and farmed fish, which are essential for enhancing the cultivation of G. p. firmispinatus and for the formulation of specific probiotics and functional feeds. Full article

(This article belongs to the Special Issue Aquatic Economic Animal Breeding and Healthy Farming)

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14 pages, 1411 KiB

Open AccessArticle

A Comprehensive Assessment of Nutritional Value, Antioxidant Potential, and Genetic Diversity in Metapenaeus ensis from Three Different Populations

by Yundong Li, Juan Chen, Song Jiang, Qibin Yang, Lishi Yang, Jianhua Huang, Jianzhi Shi, Yan Zhang, Zhibin Lu and Falin Zhou

Biology 2024, 13(10), 838; https://doi.org/10.3390/biology13100838 - 19 Oct 2024

Cited by 1 | Viewed by 1629

Abstract

Due to its high tolerance to salinity and temperature, as well as its strong adaptability, Metapenaeus ensis holds an important position in the Chinese aquaculture industry. However, studies on the evaluation of its germplasm resources remain insufficient. This research conducted an in-depth comparative [...] Read more.

Due to its high tolerance to salinity and temperature, as well as its strong adaptability, Metapenaeus ensis holds an important position in the Chinese aquaculture industry. However, studies on the evaluation of its germplasm resources remain insufficient. This research conducted an in-depth comparative evaluation of M. ensis from three representative farming regions in China: Sanya, Zhuhai, and Raoping. The nutritional analysis of muscle tissue showed no statistically significant differences in crude ash, moisture, and crude protein content among the populations (p > 0.05). However, significant differences were observed in crude fat and total sugar content (p < 0.05). The MeSY and MeRP populations had higher crude fat content than the MeZH population (p < 0.05), while the MeZH population exhibited the highest total sugar content. In terms of amino acid composition, the MeSY population had relatively higher total essential amino acid content and proportion, as well as higher total amino acid content, both of which were statistically significant (p < 0.05). A fatty acid composition analysis further highlighted the advantages of the MeRP population in several key fatty acids (p < 0.05). Physiological and biochemical analyses showed no significant differences among the three populations in total antioxidant capacity, superoxide dismutase activity, or catalase activity (p > 0.05). A genetic diversity analysis indicated that M. ensis has relatively low diversity, with the MeSY population showing higher SNP density and nucleotide diversity. A genetic differentiation analysis revealed significant genetic differentiation between the MeSY and MeZH populations, while differentiation between the MeZH and MeRP populations was relatively smaller. This comprehensive assessment of nutritional components, amino acids, fatty acids, antioxidant capacity, and genetic diversity highlights the advantages of germplasm resources from different regions. These findings provide valuable insights for future research on the genetic characteristics and breeding potential of M. ensis. Full article

(This article belongs to the Special Issue Aquatic Economic Animal Breeding and Healthy Farming)

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11 pages, 3227 KiB

Open AccessArticle

Effect of Different Opening Diet on the Growth, the Structure of the Digestive Tract and Digestive Enzyme Activity of Larval and Juvenile Mystus macropterus

by Xiaoli Li, Xingbing Wu, Xuemei Li, Nian Wei, Ming Jiang, Yongjiu Zhu and Tingbing Zhu

Biology 2024, 13(9), 749; https://doi.org/10.3390/biology13090749 - 23 Sep 2024

Cited by 3 | Viewed by 1119

Abstract

One of the crucial factors influencing the growth and viability of larvae and juveniles is their opening diets. The objective of this study was to identify suitable initial feed options for M. macropterus larvae and juveniles. A total of 1200 newly hatched M. [...] Read more.

One of the crucial factors influencing the growth and viability of larvae and juveniles is their opening diets. The objective of this study was to identify suitable initial feed options for M. macropterus larvae and juveniles. A total of 1200 newly hatched M. macropterus with an average weight of 18.3 mg and an average length of 11.58 mm were selected and randomly divided into four groups. The fish were fed with different opening diets, including rotifer, Artemia nauplii, Tubifex, and micro-diet from six days after hatching (dahs), respectively. Growth indices and activities of digestive enzymes were assessed at 10, 15, 20, 25, 30, 35, and 40 dahs. Histological examination of the structure of the digestive tract was performed at 40 dahs, while survival rates were also documented. The results demonstrated that different diets had no effect on the survival rate of larvae and juveniles of M. macropterus. The growth performance indices were ranked as follows: Tubifex group > Artemia nauplii group > micro-diet group > rotifer group. Remarkably, the Tubifex group exhibited superior growth performance, which was also reflected in the structure of the digestive tract and digestive enzyme activity. Therefore, it is recommended to include Tubifex in the diet of M. macropterus larvae and juvenile during the standardized farming process. Full article

(This article belongs to the Special Issue Aquatic Economic Animal Breeding and Healthy Farming)

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