Search Results (205)

Aquaculture has grown rapidly worldwide and has become a key source of food and employment opportunities. However, its expansion faces environmental, health, reproductive, and technological challenges that threaten its long-term sustainability. In this context, biologists play a crucial role in promoting sustainable practices and integrated management of aquaculture systems. This article reviews their main contributions to animal health, genetic improvement, assisted reproduction, and resource conservation. They also highlight their leadership in applying advanced technologies, including biotechnology, nanotechnology, and genetic engineering. Moreover, this study explores emerging research trends and emphasizes the importance of interdisciplinary training to address the evolving demands of the sector. This underscores the need to strengthen collaboration between science, technology, and public policy to ensure sustainable aquaculture. Enhancing the role of biologists is essential for overcoming current challenges and advancing efficient, ethical, and environmentally responsible aquaculture systems that meet global demand. Full article

Short-term hypothermic storage at 4 °C represents a promising non-freezing alternative for transporting bovine embryos and synchronizing assisted reproductive procedures. However, chilling induces oxidative stress, mitochondrial dysfunction, and apoptosis, which markedly impair post-preservation embryonic viability. Glutathione (GSH), a key intracellular antioxidant, may mitigate these damaging effects, yet its protective mechanisms during bovine blastocyst hypothermic preservation remain unclear. Here, we investigated the impact of exogenous GSH supplementation on the survival, hatching ability, cellular integrity, mitochondrial function, and developmental potential of bovine blastocysts preserved at 4 °C for seven days. Optimization experiments revealed that 4 mM GSH provided the highest post-chilling survival and hatching rates. Using DCFH-DA, TUNEL, and γ-H2AX staining, we demonstrated that 4 °C preservation significantly increased intracellular reactive oxygen species (ROS), DNA fragmentation, and apoptosis. GSH supplementation markedly alleviated oxidative injury, reduced apoptotic cell ratio, and decreased DNA double-strand breaks. MitoTracker and JC-1 staining indicated severe chilling-induced mitochondrial suppression, including decreased mitochondrial activity and membrane potential (ΔΨm), which were largely restored by GSH. Gene expression analyses further revealed that chilling downregulated antioxidant genes (SOD2, GPX1, TFAM, NRF2), pluripotency markers (POU5F1, NANOG), and IFNT, while upregulating apoptotic genes (BAX, CASP3). GSH effectively reversed these alterations and normalized the BAX/BCL2 ratio. Moreover, SOX2/CDX2 immunostaining, total cell number, and ICM/TE ratio confirmed improved embryonic structural integrity and developmental competence. Collectively, our findings demonstrate that exogenous GSH protects bovine blastocysts from chilling injury by suppressing ROS accumulation, stabilizing mitochondrial function, reducing apoptosis, and restoring developmental potential. This study provides a mechanistic foundation for improving 4 °C embryo storage strategies in bovine reproductive biotechnology. Full article

Oocytes cultured in vitro are exposed to high oxygen tension and lack follicular antioxidants, leading to redox imbalance. Eicosapentaenoic acid (EPA), a marine long-chain n-3 polyunsaturated fatty acid, possesses strong antioxidant activity. Here, using pigs as a model, we examined the effects of EPA on oocyte in vitro maturation (IVM) and subsequent developmental competence. Cumulus–oocyte complexes were cultured with EPA, followed by assessment of nuclear and cytoplasmic maturation and embryonic development; transcriptomic and proteomic analyses were conducted to explore underlying mechanisms. Supplementation with 10 µM EPA significantly improved maturation and blastocyst rates by reducing spindle defects, facilitating a more uniform organization of cortical granules and mitochondria. EPA increased resolvin E1 accumulation and reduced cumulus-cell apoptosis through downregulation of TNF-α and BAX and upregulation of BCL2. In MII oocytes, EPA lowered apoptosis, DNA damage, and ROS levels while enhancing SOD2 and GPX4 expression. Mitochondrial quality and turnover were improved via upregulation of PPARGC1A, NDUFS2, PINK1, LC3, FIS1, MUL1, and OPA1, alongside strengthened ER–mitochondria contacts. These findings demonstrate that EPA alleviates oxidative stress, optimizes mitochondrial function, and enhances porcine oocyte maturation and developmental competence in a parthenogenetic model, highlighting its potential as a marine-derived functional additive for reproductive biotechnology. Future studies will be required to validate these effects under fertilization-based embryo production systems and to further refine dose–response relationships using expanded embryo-quality endpoints. Full article

Feminization is an important biotechnological approach in aquaculture for species in which females exhibit superior growth and higher market value. The long-whiskered catfish (Mystus gulio), a euryhaline species cultivated in both monoculture and co-culture systems, contributes to sustainable aquaculture by grazing on uneaten feed and maintaining pond cleanliness. This study evaluated the effects of dietary 17β-estradiol (E2) at 0, 10, 30, and 60 mg/kg, incorporated into conventional and microencapsulated feeds, on the feminization and early growth of M. gulio larvae. Treatments were administered during the weaning stage for 14 and 21 days under controlled rearing conditions. Results showed that larvae fed microencapsulated feed containing 60 mg/kg E2 achieved the highest specific growth rate (26.91 ± 1.92%/day), feed efficiency (164.76 ± 33.23%), and feminization success (99.73 ± 0.04%). Hormonal assays confirmed elevated estradiol and reduced testosterone levels, consistent with ovarian development observed in histological sections. Gene expression analysis further supported these findings through the significant upregulation of cyp19a, erb1, and erb2 mRNA levels. Overall, this study demonstrates that microencapsulated hormone feeding is an effective and environmentally responsible strategy for achieving monosex female populations in M. gulio, enhancing productivity, reproductive performance, and sustainability in aquaculture systems. Full article

The severe decrease in natural sturgeon stocks has led to intensified efforts toward the development of sturgeon aquaculture and the application of reproductive biotechnologies to ensure sustainable production. In cultured male Acipenser ruthenus (sterlet), spermiation must be hormonally induced to obtain high-quality semen; however, reducing hormonal dosages while maintaining or improving sperm quality remains a major challenge. In this study, we investigated the effects of reduced doses of carp pituitary extract (CPE) and luteinizing hormone-releasing hormone agonist (LH-RH) combined with Apilarnil supplementation on spermiation and semen quality in A. ruthenus. Semen volume, pH, sperm concentration, total sperm output, total motility, and spermatozoa velocity were evaluated. Administering a reduced CPE dose (1.1 mg·kg⁻¹) combined with 1 g of Apilarnil significantly increased semen volume, sperm concentration, and total sperm output, as well as improved sperm kinematic parameters (total motility and velocity) compared with the conventional hormonal protocol. Furthermore, treatments using 50% of the standard LH-RH dose supplemented with 1 g or 2 g of Apilarnil resulted in significantly higher sperm motility and velocity than observed in the control group. These results demonstrate that Apilarnil supplementation allows for a substantial reduction in exogenous hormonal doses while enhancing spermiation efficiency and semen quality in sterlet, supporting the spermiation-induction protocol for sturgeon aquaculture. Full article

Dimethyl sulfoxide (DMSO) is widely utilized in the vitrification of oocytes, but DMSO exhibits concentration-dependent toxicity, which can compromise oocyte developmental potential by disrupting key cellular processes. This study reports the first successful use of cold shock protein B (CspB protein) as a substitute for DMSO in vitrification solutions for oocyte vitrification. Combining dynamics simulations and experimental validation, we demonstrated CspB’s ability to inhibit ice crystallization and recrystallization by stabilizing its position at the ice–water interface and reducing ice formation rates. Recombinant CspB was successfully expressed and shown to bind to the oolemma. In vitrification solutions, CspB (1–2 mg/mL) effectively reduced ice crystal size and enabled a significant reduction or complete replacement of DMSO. This strategy markedly improved the post-thaw survival rates of both mouse and bovine metaphase II (MII) oocytes. Furthermore, oocytes vitrified with an optimized formulation (15% ethylene glycol + 2 mg/mL CspB) exhibited developmental competence (cleavage and blastocyst rates), oxidative stress markers (ROS, GSH), mitochondrial function (membrane potential and content), and apoptosis levels (Caspase-3/9) comparable to those treated with a standard DMSO-containing system. Transcriptomic analysis revealed that CspB’s cryoprotection involves the modulation of the mTOR signaling pathway. This role was functionally confirmed, as activation of mTOR abolished CspB’s beneficial effects, reinstating oxidative damage, mitochondrial dysfunction, and apoptosis. Thus, the CspB protein replaces DMSO with direct ice crystal formation suppression and mTOR-mediated oxidative stress regulation. This study offers a protein-based alternative to conventional permeable cryoprotectants. This approach holds promise for improving reproductive biotechnologies across species. Full article

In African countries and many developing countries, communal farmers rely on livestock such as cattle, goats, and sheep to support food security, income, and agricultural activities. Fertility in these animals is often limited by poor semen quality, which reduces sperm concentration, total motility, and morphology. Assisted reproductive biotechnologies, including semen cryopreservation and artificial insemination, are increasingly essential to enhance reproductive efficiency and productivity. Although cryopreservation preserves valuable genetic material, it can damage sperm cells, making high-quality extenders critical for protection. Common extenders, such as Tris-egg yolk glucose, citrate-sugar-based, and skimmed milk solutions, supply nutrients and protect sperm membranes. To further minimize oxidative stress, antioxidants are incorporated, with growing interest in plant-derived compounds. Many plants contain bioactive substances, including antioxidants and phytomelatonin, which can enhance sperm quality safely and effectively. This review examines the use of plant-based antioxidants during semen cryopreservation and highlights their potential to improve fertility in mammalian livestock. Full article

Small pelagic fish, including sardines, are essential to global fisheries and aquaculture feed production. However, these species are increasingly exposed to intense exploitation. In Chile, the common sardine (Strangomera bentincki), endemic to the Humboldt Current System, supports major industrial and artisanal fisheries. Landings are expected to reach 300,000 tons by 2025, mostly for fishmeal production. As a keystone species, S. bentincki is highly sensitive to environmental variability during early development, which can reduce recruitment and threaten long-term population sustainability. This interdisciplinary approach integrates ecological and biotechnological perspectives to assess the feasibility of controlled juvenile sardine production in land-based Ecological Aquaculture (EA) systems, including Recirculating Aquaculture Systems (RAS) and Integrated Multi-Trophic Aquaculture (IMTA), which are designed to reduce environmental impacts. These systems enable precise control of temperature, feeding regimes, and water quality, facilitating investigations into larval and juvenile survival, growth performance, and physiological responses under variable thermal and nutritional conditions. Emphasis is placed on fatty acid metabolism during ontogeny, particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), which are essential for somatic growth, reproductive development, and thermal tolerance. Developing standardized protocols for juvenile S. bentincki culture addresses key gaps in husbandry and physiology (temperature threshold, nutrient density, larval growth rate, etc.) while introducing a novel ecological–aquaculture integration framework. This approach links early-life ecology with applied rearing techniques to support stock enhancement, strengthen artisanal fisheries, and promote sustainable aquaculture diversification under increasing environmental variability. Full article

Artificial insemination (AI) is a key reproductive biotechnology for genetic improvement in sheep. However, its efficiency remains lower and more variable than in most other livestock species. This review critically synthesizes the historical foundations of sheep AI, including methodological principles established by the Soviet school, and evaluates how these concepts have been further developed and adapted to contemporary reproductive biology. Particular emphasis is placed on estrous synchronization protocols, semen processing and cryopreservation, and insemination techniques. We highlight how anatomical constraints of the ovine cervix, seasonal reproductive physiology, and species-specific characteristics of ram sperm collectively limit fertility outcomes, especially when frozen–thawed semen is used. Comparative analysis of cervical, transcervical, and laparoscopic insemination methods indicates that laparoscopic AI remains the most reliable approach, although recent advances in catheter design and semen handling have improved the feasibility of less invasive techniques. This review further discusses emerging approaches, including sperm sex-sorting, alternative recovery methods, and early-stage spermatogonial stem cell–based technologies, emphasizing both their potential applications and current limitations. Overall, the available evidence suggests that future progress in sheep AI will depend on the integrated optimization of hormonal synchronization, semen preservation, and insemination strategies, rather than on isolated technical innovations. Full article

Oocyte-granulosa cell complexes (OGCs) cultivation is crucial for advancing reproductive biotechnology but remains incomplete and needs further optimization. Insulin-like growth factor-I (IGF-I) regulates granulosa cell proliferation and apoptosis, and numerous studies have confirmed its role in promoting ovarian follicle development. Porcine follicular fluid (PFF) contains factors beneficial for oocyte growth, which may enhance oocyte development. To investigate whether IGF-I and PFF improve the in vitro culture efficiency of porcine OGCs, we cultured OGCs with IGF-I (0, 10, 50, 100 ng/mL) and PFF (from 3 to 6 mm follicles) at concentrations of 0, 2.5%, 5%, 10%, respectively. The results revealed that 50 and 100 ng/mL IGF-I significantly increased the antrum formation rate of OGCs (from 61.11 ± 7.35% to 88.89 ± 7.35%) and diameter growth of oocytes (from 108.77 ± 0.27 µm to 114.94 ± 0.58 and 113.29 ± 0.50 µm, respectively). However, only the 50 ng/mL group, but not the 100 ng/mL group, significantly improved the maturation rate (38.13 ± 3.77% vs. 25.00 ± 3.27%, p < 0.05) of oocytes. Additionally, 50 ng/mL IGF-I downregulated BAX (a pro-apoptotic gene) and upregulated BCL-2 (an anti-apoptotic factor) in granulosa cells, ultimately reducing apoptosis. In contrast, none of the PFF doses used in this study induced the formation of enclosed antrum-like structures in OGCs, nor did they significantly enhance their in vitro development. Our findings demonstrate that 50 ng/mL IGF-I effectively promotes the in vitro growth of porcine early antral follicle-derived OGCs by reducing apoptosis, whereas tested PFF concentrations had no beneficial effects and induced abnormal granulosa cell growth. How PFF modulates the adherent and spreading growth of granulosa cells has not been fully elucidated and requires further clarification. Full article

Garlic’s vegetative reproduction limits genetic improvement, necessitating advanced biotechnological tools like protoplast culture. However, efficient protoplast regeneration in monocots such as garlic remains a significant challenge. This study establishes an optimized protocol for embryogenic callus induction and subsequent protoplast-to-plant regeneration in garlic (Allium sativum L.), aiming to overcome current limitations using suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, and phytosulfokine-alpha (PSK). We successfully induced embryogenic callus from four garlic accessions and refined protoplast isolation and culture conditions. Key optimizations included using a specific enzyme mixture (2% cellulase R-10 and 0.2% pectolyase Y23) for high yields (from 0.8 to 2.1 × 10⁶ protoplasts per g FM) of viable (approx. 90%) protoplasts and employing the enriched K8M culture medium. Short exposure of protoplasts to SAHA (0.05 or 0.1 µM) significantly improved microcallus formation and plant regeneration. Notably, only callus derived from SAHA-treated cultures displayed regeneration potential, highlighting its pivotal role in embryo differentiation and development. This optimized protocol achieved a 70% success rate for plant acclimatization to ex vitro conditions, with 97% of regenerated plants retaining the ploidy of the donor accession. We demonstrate that SAHA and PSK application enhances garlic protoplast regeneration efficiency. This reliable system provides the groundwork for advanced biotechnological applications, including gene editing technologies in garlic. Full article

Citrus species develop fruits through both sexual reproduction and parthenocarpy, following a growth pattern with an initial exponential phase dominated by cell division in the ovary wall, followed by a linear phase driven by cell expansion in juice vesicles. Sustained carbohydrate supply is essential to support the metabolic energy required for these processes, which are tightly regulated by hormonal signaling pathways involving gibberellins (GAs), auxins (IAA), cytokinins, and abscisic acid (ABA). Recent studies across cultivars have identified genes associated with hormone biosynthesis, carbohydrate metabolism, cell cycle regulation, and abscission in ovule and pericarp tissues. Manipulation of these hormones through targeted treatments and cultural practices has shown potential to enhance fruit set and growth. Notably, exogenous GA₃ application promotes fruit set in parthenocarpic cultivars by upregulating GA20ox2/GA3ox and CYCA1.1, whereas synthetic auxins enhance fruit enlargement by improving assimilate partitioning and water uptake. Optimizing such treatments, however, requires a comprehensive understanding of physiological, environmental, and agronomic factors influencing fruit development. This review summarizes recent advances in hormonal and molecular regulation of citrus fruit set and developments, assesses applied strategies to improve productivity, and identifies current knowledge gaps needed to refine biotechnological and management aimed at enhancing both yield and fruit quality. Full article

Tribolium castaneum, the red flour beetle, is both a major pest of stored products and a valuable genetic model. Odorant Binding Proteins (OBPs), traditionally associated with olfaction, are now recognized as multifunctional, contributing to detoxification, immunity, and reproduction. This review synthesizes recent advances in the molecular structure, gene expression, and functional characterization of T. castaneum OBPs—particularly TcOBPC11, TcOBPC12, TcOBPC17, and TcOBP7G. Experimental evidence, including RNA interference, ligand-binding assays, and expression profiling, supports their role in defense against xenobiotics. Comparative genomic analyses reveal lineage-specific expansions and adaptive evolution, especially in Minus-C OBPs. Translational applications include RNA interference (RNAi)-based pest control, OBP-targeting repellents, and biosensors. Outstanding challenges remain, including structural resolution and functional redundancy. Future research integrating CRISPR, single-cell transcriptomics, and structural biology will be critical to decode OBP regulatory networks and leverage their potential in pest management and biotechnology. Full article

Bone health might be closely associated with male fertility, yet the molecular pathways remain poorly characterized. We demonstrate that undercarboxylated osteocalcin (ucOCN), a bone-derived hormone, initiates a signaling cascade that stimulates testosterone biosynthesis in porcine Leydig cells. Mechanistically, ucOCN binding to membrane receptor GPRC6A elevates intracellular cAMP levels and sequentially activates PKA, MEK, and ERK. ERK translocates to the nucleus and phosphorylates the transcription factor CREB. Activated CREB binds directly to promoter regions of the key steroidogenic genes and boosts testosterone production. The genetic or pharmacological inhibition of GPRC6A, PKA, MEK, or ERK signaling disrupts CREB activation and abolishes both steroidogenic gene expression and testosterone synthesis. Crucially, the phospho-switch S298 as a previously unrecognized phosphorylation site through which MEK regulates osteocalcin (OCN) signaling was identified. Collectively, our results indicate that ucOCN interacts with GPRC6A to promote testosterone synthesis in Leydig cells via the PKA-MAPK/ERK-CREB pathway. The above findings elucidate a fundamental endocrine axis between bone and the male reproductive system, offering novel mechanistic insights and potential therapeutic strategies for improving male fertility. Full article

Spermatogonial stem cells (SSCs) are the only adult male germline stem cells capable of lifelong self-renewal and differentiation into spermatozoa. Scalable ex vivo survival is essential for endangered species germplasm banking, genetic resource conservation, and male infertility therapy. Here, chitosan (CO) or chitosan oligosaccharide (COS) was cross-linked into injectable, biodegradable 3D hydrogels loaded with the natural astaxanthin (AST). CCK-8 optimization identified 0.3% CO + 0.2% AST (CHAG) and 0.2% COS + 0.2% AST (COAG) as superior formulations. After 7 or 14 d of 3D culture, CHAG yielded significantly more colonies than controls (p < 0.01), with elevated EdU incorporation, alkaline phosphatase activity, and positive OCT4 and PLZF staining, confirming preserved stemness. Caspase-3 expression was markedly reduced, indicating the AST-mediated suppression of oxidative apoptosis. RNA-seq showed distinct transcriptome pathways (p < 0.01): CHAG up-regulated adhesion and ECM–receptor and cell cycle pathways, whereas COAG enriched immune-modulatory and signaling modules, enabling context-specific use. AST-loaded CO/COS hydrogels are inexpensive, cytocompatible, and scalable, doubling as a biomimetic niche that accelerates SSC proliferation while delaying senescence. The platform provides a robust, controllable 3D system for SSC expansion and establishes a pre-clinical basis for translating CO/COS/AST composites to reproductive stem cell biotechnology. Full article