Search Results (63)

Most of the publications on Anisakis simplex (Rudolphi, 1809) focus upon systematic aspects and zoonotic risk but there is lack of detailed information on infection and cellular immune response of the gonads. The current investigation detected whether gonadal infection by A. simplex affects reproductive development and how Atlantic mackerel, Scomber scombrus (L.), responds immunologically. Thirty-four specimens out of 62 S. scombrus (55%) individuals had the larvae on or in the gonads, and live and calcified dead larvae often co-occurred. Nematode larvae were found in both mature and immature gonads. The intensity of infection varied from 1 to 31 nematodes per gonad (5.68 ± 5.53, mean ± standard deviation). In ovaries that harboured the nematode (inside the organ and in the mesenteries around it), in close vicinity to the larvae, mast cells (MCs), rodlet cells (RCs), macrophages, and macrophage aggregates (MAs) occurred. Fewer of the above cells were observed in the mesenteries of parasitized testes. In the gonads of infected fish, within the granulomas that surrounded the calcified and live larvae, putative epithelioid cells, fibroblasts, MCs, MAs and collagen fibres were present. The absence of a correlation between the intensity of infection and the host gonadosomatic index in female and male gonads might indicate that A. simplex larvae do not affect the production of gametes and gonad development in Atlantic mackerel. Our results suggest that localized encapsulation represents an effective tolerance strategy allowing parasite persistence while preserving host reproductive function. Full article

Oxidative stress is a fundamental mechanism that impacts reproductive function by altering gamete quality, fertilisation, and the initial development of embryos. Excessive reactive oxygen species lead to the oxidation of polyunsaturated fatty acids in the cell membranes of sperm, oocytes, and adjacent somatic cells. F2-isoprostanes and isofurans are two of the most dependable indicators of oxidative lipid damage among the byproducts generated during free radical-mediated lipid oxidation. Both arise from the non-enzymatic peroxidation of arachidonic acid and provide a chemically stable depiction of in vivo oxidative processes. Reproductive studies indicate that elevated levels of F2-isoprostanes are associated with diminished sperm motility, compromised membrane stability, and an increased risk of DNA fragmentation in various forms of male infertility. Lipid peroxidation products have been detected in follicular fluid inside the female reproductive system, suggesting a relationship between oxidative imbalance, granulosa cell metabolism, and oocyte competency. Isofurans, which are more prevalent in the presence of elevated oxygen levels, may indicate oxidative stress in mitochondria and complications with cellular respiration. The current comprehension of lipid peroxidation indicators in infertility and assisted reproduction remains insufficient. This review aims to synthesise current information on isoprostanes and isofurans as reliable indicators of oxidative lipid damage in reproductive biology, highlighting their effects on gamete quality, mitochondrial dysfunction, and results in assisted reproduction. Our research seeks to clarify the biological importance of current experimental and clinical findings, highlighting their potential as clinically relevant biomarkers in reproductive medicine. Full article

Proteostasis, defined as the coordinated regulation of protein synthesis, folding, trafficking, and degradation, is essential for maintaining cellular integrity and supporting normal development. During reproduction and early life stages, efficient proteostasis is crucial for gamete quality, successful fertilization, embryonic development, and neurodevelopmental outcomes. Increasing evidence suggests that impaired proteostasis contributes to infertility and may be intertwined with biological vulnerabilities associated with assisted reproductive technologies [ARTs]. This review provides an integrative perspective on the role of disrupted proteostasis in infertility, ART procedures, and neurodevelopmental differences [NDD]. We review epidemiological and molecular findings indicating proteostasis failure in both male and female infertility, with particular emphasis on molecular chaperones. Among these, heat shock protein 60 [Hsp60] is discussed as a central mediator linking mitochondrial function, protein quality control, and reproductive competence. We further highlight that ART procedures coincide with sensitive periods of epigenetic reprogramming and proteostasis regulation during early embryogenesis, indicating that disturbances in proteostasis may affect epigenetic stability and subsequent neurodevelopmental outcomes. In addition, this review emphasizes the importance of proteoforms and proteome complexity as critical determinants of reproductive success and neurodevelopmental robustness in the context of ART. Finally, we discuss the potential of proteomic and chaperone-based biomarkers as emerging tools to optimize ART strategies, improve gamete and embryo selection, and enhance risk assessment and clinical outcomes. The current review underscores proteostasis as a fundamental yet underrecognized mechanism linking reproductive biology, ART outcomes, and long-term neurodevelopment while highlighting future directions for translational investigations. Full article

The Manila clam Ruditapes philippinarum is a commercially important bivalve worldwide, with China being the leading producer. While the reproductive biology of this species has been extensively studied in its native or long-established ranges, knowledge of how populations cultured from non-native seed sources adapt their reproductive cycles to new environmental conditions remains limited. In this observational study, we investigated the annual reproductive cycle of a Manila clam population originating from subtropical waters (Zhejiang Province, Southern China) that was cultured in temperate aquaculture grounds in Zhuanghe Bay, Northern China. Monthly histological examination of 50 clams demonstrated that the gametogenic cycle synchronized between male and female clams. Gametogenesis started in March when seawater temperature exceeded 5.7 °C, and most gametes matured by May. A distinct bimodal spawning pattern was observed: a minor spawning event occurred from May to July, followed by a major spawning phase from September to November after a one-month gonadal recovery period in August. The condition index (CI), analyzed monthly in 30 clams, effectively reflected reproductive stages, increasing during gametogenesis and declining sharply during spawning, with its amplitude indicating spawning intensity. Seawater temperature was identified as the primary regulatory factor driving reproductive development from gametogenesis to spawning, while food availability (indicated by chlorophyll a concentration) played a crucial role in supporting gonadal recovery during summer. These results align with observations in other temperate populations, demonstrating that subtropical-origin clams can successfully acclimate their reproductive cycles to temperate environmental conditions. This study provides the first comprehensive description of the reproductive biology of transplanted Manila clams in Northern China, offering critical benchmarks for optimizing hatchery production schedules and informing sustainable fishery management practices in the region. Full article

Background/Objectives: Infertility is a multifactorial condition with an etiopathology that remains largely unclear. Although substantial evidence implicates oxidative stress (OS) as a key contributor to both male and female infertility, targeted strategies for OS-mediated reproductive dysfunction are still not well defined and require further investigation. Ubiquinol is the reduced form of Coenzyme Q10 involved in mitochondrial bioenergetics. It can be synthesized by humans endogenously or provided by dietary sources—typically egg yolks, oily fish, organ meats, and in smaller amounts in nuts and seeds and leafy green vegetables. The present article reviews possible mechanisms through which Ubiquinol plays a role in the regulation of fertility and reproduction, discussing why it could be positioned as a conditionally essential nutrient. Several questions and areas for further inquiry are also proposed. Methods: The present position paper narratively summarizes evidence related to Ubiquinol fertility and reproduction, focusing on the literature from PubMed, Science Direct, and Semantic Scholar. Results: Research advancements suggest that when physiological demands rise during certain life stages, e.g., the reproductive years, the amount of Ubiquinol produced internally may not be enough to meet heightened needs, particularly with advanced maternal/paternal age. This places a heavier reliance on obtaining Ubiquinol from the diet, thus presenting itself as a conditionally essential nutrient during certain life stages. Conclusions: Overall, Ubiquinol appears to enhance mitochondrial energy production and antioxidant defense in gametes, a process that appears to aid sperm function, oocyte quality, and early embryo development. Collectively, these data indicate a key physiological role for Ubiquinol in male and female fertility, especially given its age-related decline. Full article

The apodid sea cucumber Chiridota laevis has been a documented member of endobenthic marine communities in northern waters for over a century and the rare studies available on its biology identify it as distinctive species and promising model for research. The present study sought to elucidate fundamental aspects of its life history that remained unresolved. Adults were determined to be protandric, with individuals primarily demonstrating solely male or female gametes from winter (close to spawning) to the spring and summer months before undergoing a sex change in the fall months. Additionally, gametes of both sexes reached maturity synchronously in late winter (February to March). In mesocosms, free spawning occurred in February, as the temperature reached ~2.0 °C. The negatively buoyant eggs were encased in a sticky casing and fell to the sediment where they adhered to each other to form a mat on the muddy substratum. The realized fecundity was ~15,000 offspring. Development was lecithotrophic, demersal, and abbreviated, characterized by the absence of a pelagic larval stage. Embryos reached the gastrula stage after about 7 days post fertilization; the calcareous ring appeared at 6 weeks, and juveniles hatched from the sticky casing at 7 weeks, immediately becoming endobenthic. The size of late embryos and juveniles remained similar (~350 μm) until they began actively feeding at about 10 weeks of age. Feeding juveniles more than doubled in size in the first week (740 μm), reached 3.5 mm by year one, and measured up to 11 mm by year two. This growth rate suggests that it may take this species up to 7 years to reach adult size at ~24 mm contracted length. Full article

Background/Objectives: Inactivation of the dnd gene involved in the development of primordial germ cells (PGCs) leads to the loss of gametes and halts reproductive development. Studies on sterile fish allow for the identification of genes and processes associated with GC differentiation. Methods: Atlantic salmon with GC-ablated testes were produced by temporal silencing of dnd. Gene expression was analyzed in sterile and fertile testes using 44k microarray and qPCR. Results: In sterile testes, transcripts of several GC markers were detected at low levels, suggesting the presence of cells with a GC-related expression profile that failed to initiate spermatogenesis. Expression of 260 genes was undetectable in the gonads of sterile males and females, and 61.5% of these were also inactivated during first maturation of fertile testes. This group was enriched with genes highly expressed in the brain, including those involved in endocrine and paracrine regulation, synaptic transmission, and numerous genes critical for brain development; among them, 45 genes encoding homeobox proteins. Another group of 229 genes showed increased expression in developing testes and included genes involved in neurosecretion and brain development regulation. GC-ablated testes showed increased expression of reproductive regulators such as amh and sdy and numerous immune genes, suggesting a reprogramming of GC-depleted testes. Temporal silencing of dnd indicated common developmental processes in the brains and gonads of Atlantic salmon testis that become inactive in testes at first maturation. These processes may play roles in PGC homing, the creation of a specific environment required for spermatogenesis, or facilitating communication between the gonads. Full article

Cannabis sativa L. is a dioecious species known to produce over 1600 chemical constituents, including more than 180 cannabinoids classified into 11 structural groups. These bioactive compounds are predominantly synthesised in the glandular trichomes of female inflorescences. However, sex determination in C. sativa is influenced by both genetic and environmental factors, often leading to the development of male flowers on female plants. This unintended fertilisation reduces cannabinoid yield and increases genetic heterogeneity and challenges in medical cannabis production. Haploid and doubled haploid (DH) technologies offer a promising solution by rapidly generating homozygous lines from gametophytic (e.g., unpollinated ovaries and ovules) or sporophytic tissues (e.g., anthers and microspores) via in vitro culture or chromosome reduction during hybridisation. In land plants, the life cycle alternates between a diploid sporophyte and a haploid gametophyte generation, both capable of mitotic division to form multicellular bodies. A single genome regulates this phase transition and encodes the molecular, genetic, and epigenetic mechanisms that precisely control the developmental processes unique to each generation. While the application of haploid technology in C. sativa remains limited, through recent progress in haploid induction (HI) and CRISPR-based genome editing, the direct modification of haploid gametes or embryos enables the creation of null homozygous lines following chromosome doubling, improving genetic uniformity. Understanding the molecular mechanisms of spontaneous chromosome doubling may further facilitate the development of elite cannabis genotypes. Ultimately, enhancing the efficiency of DH production and optimising genome editing approaches could significantly increase the speed of genetic improvement and cultivar development in Cannabis sativa. Full article

The presence of hemoglobin beta mRNA and protein in the female gonad suggests that hemoglobin beta may be present in the male gonad as well. The frequent occurrence of hemoglobin beta in nonerythroid tissues with hypoxic environments further underscores a potential role for hemoglobin beta in the testis to facilitate the regulation of oxygen availability for the developing germ cells and Sertoli cells since they are separated from the blood supply by multiple tissues. The presence of mRNA and protein were evaluated by qPCR and immunohistochemistry, respectively. The mRNA and protein for hemoglobin were detected in juvenile and postpuberal porcine testes. The most intense immunolabelling for the protein was present in testicular interstitial cells, in contrast to previously reported ovarian labelling in close proximity to the gamete and observed in porcine ovaries in the current study. The observed decrease in mRNA expression of hemoglobin beta with age is probably due to the change in testicular composition (increase in seminiferous tubule compartment) with age. The localization of hemoglobin beta in the testis will contribute to future understanding of its potential function in facilitating oxygen availability to seminiferous tubules or reducing oxidative damage. Full article

Here, we confirm the presence of two species of caridean shrimps for the first time in Brazil: Latreutes parvulus and Ambidexter cochensis. During active samplings conducted in December 2023, April 2024 and September 2024 on the rocky shore of Prainha da USP (Ubatuba municipality, São Paulo state, southeastern Brazil), we captured five ovigerous females of L. parvulus and fifteen individuals of A. cochensis (five males, three non-ovigerous females and seven ovigerous females). All the females of L. parvulus exhibited eyestalks with small, truncated processes separating the cornea from the stalk, a unique feature of this species. On the other hand, all specimens of A. cochensis exhibited a unique combination of characteristics: a rostrum with an apex bifid, a stylocerite bearing a lateral spinule and a transverse row of setae between the anterior pair of spines, and three longitudinal rows of setae on the telson. Also, males of A. cochensis had the tip of their appendix masculina armed with four simple apical setae and another two setae positioned below them. All analyzed shrimps had fully developed gametes in their reproductive systems, indicating breeding populations in this area. This is the first record of L. parvulus on the Atlantic coast of South America and a new meridional distribution limit for A. cochensis. Full article

Extracellular vesicles (EVs) are gaining recognition for their essential role in enhancing gamete quality and improving outcomes in assisted reproductive technologies. These nanosized particles, released by cells, carry proteins, lipids, and RNAs, facilitating critical cell communication and offering the potential to enhance gamete maturation and improve fertilization rates. Most research on males has concentrated on seminal plasma, a complex fluid produced by the testes and accessory glands vital in modulating sperm fertility potential. The components of seminal plasma significantly affect sperm functionality, embryo survival, and placental development, making this a prominent area of interest in reproductive biology. The EVs within seminal plasma contribute to maintaining sperm membrane stability, enhancing motility, and promoting capacitation, which may influence the female reproductive tract following mating. In females, EVs have been identified in both the follicular and uterine environments, where effective embryo–maternal communication is crucial. The oviduct epithelium supports gamete transport and early embryonic development, with EVs found in oviductal fluid playing a key role in reproductive processes. These EVs support the embryo’s growth in the nutrient-rich uterine environment. These important studies underscore the significant role of EVs in transporting essential molecular compounds to gametes and embryos, leading to an enhanced understanding and potential manipulation of reproductive processes. This review aims to summarize the current research on the benefits of EVs in gamete manipulation and embryo development, highlighting their promising implications for reproductive health. Full article

Cannabis (Cannabis sativa) is a versatile crop belonging to the Cannabaceae family, and is dioecious, typically with separate male and female plants. The flowers of female plants, especially the trichomes, accumulate relatively higher contents of cannabinoids compared with those of male plants. For this reason, to obtain seeds that are genetically female, it is desirable to induce the development of male flowers on a female plant that produces genetically female haploid gametes. Silver thiosulfate (STS) is a highly effective chemical for male flower induction. We investigated male flower induction in three commercial cultivars of female cannabis (Spectrum303, SuperwomanS1, and CBGambit) regarding the treatment frequency, stage of application, and concentration of STS applied as a foliar spray. All three cultivars showed adequate induction of male flowers in response to 1.5 mM STS applied at the early reproductive stage. In particular, SuperwomanS1 was most highly responsive to induction of male flowers, even when treated with 0.3 mM STS at the early reproductive stage. Treatment with three applications of STS was more effective compared with a single application, but a single application of 1.5 mM STS at the early reproductive stage was sufficient for male flower induction. A single STS application during the middle stage of reproductive growth was inadequate for induction of male flowers. However, 6 weeks after three applications of STS, CBGambit exhibited approximately 54% male flower induction at 0.3 mM STS, Spectrum303 showed approximately 56% induction at 3 mM STS, and SuperwomanS1 yielded approximately 26% induction at 1.5 mM (expressed as percentage of total number of individuals with the induced male flowers). Pollen stainability tests using KI-I₂ solution and Alexander’s staining showed high pollen viability with over 65% at different single STS concentrations, indicating that pollen grains induced by STS have sufficient viability for the self-pollination. This study demonstrated that different cultivars of cannabis respond diversely to different STS concentrations and highlighted the potential benefits of three STS applications during the middle reproductive stage for cannabis breeding. Full article

Many local chicken breeds are rapidly declining and even facing extinction due to a variety of factors such as indiscriminate crossbreeding, climate fluctuations, epidemic outbreak, and environmental changes. Developing effective preservation strategies is important to address this situation. The special reproductive characteristics and gamete morphology of chickens pose challenges for preserving genetic heritage through the cryopreservation of genetic materials. Currently, gonad and primordial germ-cell cryopreservation and transplantation are the most promising approaches, especially for the genetic information in the W chromosome of female birds. The study of establishing sterile recipients is crucial for increasing the efficiency of the colonization of transplanted donor tissues and cells. Several classical methods, including ovariectomy and testectomy, busulfan, and irradiation, have been employed to deplete endogenous germ cells in recipient males before transplantation. These methods rely on the toxicity of chemical reagents and physical stimulation to kill germ cells. Recent advances in gene-editing technology have introduced sterile hosts via the knocking out of genes relevant to germ cells’ development. This review explores state-of-the-art technologies for preparing infertile avian recipients (mainly chickens) and aims to provide guidance for the conservation of poultry genetic material and breed restoration. Full article

Reproductive failure in dogs is often due to unknown causes, and correct diagnosis and treatment are not always achieved. This condition is associated with various congenital and acquired etiologies that develop inflammatory processes, causing an increase in the number of leukocytes within the female reproductive tract (FRT). An encounter between polymorphonuclear neutrophils (PMNs) and infectious agents or inflammation in the FRT could trigger neutrophil extracellular traps (NETs), which are associated with significantly decreased motility and damage to sperm functional parameters in other species, including humans. This study describes the interaction between canine PMNs and spermatozoa and characterizes the release of NETs, in addition to evaluating the consequences of these structures on canine sperm function. To identify and visualize NETs, May–Grünwald Giemsa staining and immunofluorescence for neutrophil elastase (NE) were performed on canine semen samples and sperm/PMN co-cultures. Sperm viability was assessed using SYBR/PI and acrosome integrity was assessed using PNA-FITC/PI by flow cytometry. The results demonstrate NETs release in native semen samples and PMN/sperm co-cultures. In addition, NETs negatively affect canine sperm function parameters. This is the first report on the ability of NETs to efficiently entrap canine spermatozoa, and to provide additional data on the adverse effects of NETs on male gametes. Therefore, NETs formation should be considered in future studies of canine reproductive failure, as these extracellular fibers and NET-derived pro-inflammatory capacities will impede proper oocyte fertilization and embryo implantation. These data will serve as a basis to explain certain reproductive failures of dogs and provide new information about triggers and molecules involved in adverse effects of NETosis for domestic pet animals. Full article

There has been emerging research linking per- and poly-fluoroalkyl substances (PFAS) to gamete viability and fertility. PFAS, prevalent in the environment and water supplies, undergo slow degradation due to their C-F bond and a long half-life (2.3–8.5 years). In females, PFAS inhibit the hypothalamic–pituitary–gonadal (HPG) axis, reducing follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels, leading to the inhibition of androgen and estradiol production. PFAS have been found to cause detrimental effects on egg quality through impairing folliculogenesis. In males, PFAS can impair sperm motility and morphology: two fundamental qualities of successful fertilization. PFAS exposure has been proven to inhibit testosterone production, sperm capacitation, and acrosomal reaction. After fertilization, the results of PFAS exposure to embryos have also been investigated, showing reduced development to the blastocyst stage. The aim of this review is to report the main findings in the literature on the impact of PFAS exposure to gamete competency and fertilization capability by highlighting key studies on both male and female fertility. We report that there is significant evidence demonstrating the negative impacts on fertility after PFAS exposure. At high doses, these environmentally abundant and widespread compounds can significantly affect human fertility. Full article