2,3,7,8-Tetrachlorodibenzo-p-dioxin alters steroid secretion but does not affect cell viability and the incidence of apoptosis in porcine luteinised granulosa cells

The compound 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a by-product of human industrial activity, was found to affect ovarian steroidogenesis in animals, but the mechanism of its action is still unclear. The aims of the study were to examine the effect of TCDD on (1) progesterone (P4) and oestradiol (E2) production by granulosa cells isolated from medium (3–6 mm) and preovulatory (≥ 8 mm) porcine follicles, (2) the viability of the cells, and (3) the incidence of apoptosis. Porcine granulosa cells were cultured (48 h) with or without TCDD (100 pM, 100 nM). Steroid hormone concentrations in the medium were determined by radioimmunoassay. The viability of granulosa cells was tested spectrophotometrically (alamarBlue™ assay). Apoptosis was evaluated by flow cytometry using Annexin V and by TUNEL assay. The higher dose of TCDD (100 nM) significantly inhibited P4 and stimulated E2 production by luteinised granulosa cells isolated from medium follicles. The lower dose of TCDD (100 pM) significantly stimulated P4 and inhibited E2 secretion by the cells isolated from preovulatory follicles. None of the two TCDD doses affected cell viability or induced apoptosis in granulosa cells. In conclusion, TCDD directly affected steroid production by granulosa cells obtained from mature pigs, but the effect of TCDD was not due to its cytotoxicity

Preservation of fish male germplasm in Poland

The natural resources of a country, including ichthyofauna, constitute a vital aspect of its national heritage. Fish populations are threatened with loss of biodiversity as a result of human activity (anthropopressure), resulting in water pollution, habitat destruction and overfishing. Additionally, the escalating threat is exacerbated by climate change, primarily manifested in periodic reservoir and watercourse desiccation. Genetic variability of captive is also threated as fish raised in hatcheries are susceptible to bacterial and viral diseases. Therefore, methodologies for fish sperm cryopreservation aimed at safeguarding the gene pool of both natural and captive fish populations assume paramount importance for their conservation and mitigation of irreversible losses, particularly crucial in light of increasing ecological disasters. This paper offers an overview of cryopreservation research in Poland, tracing back to early initiatives in the 1970s concerning carp (Cyprinus carpio) semen and culminating in recent advancements, where standardized cryopreservation methodologies were developed. We delve into the freezing results of semen of various fish species, encompassing both wild specimens like whitefish (Coregonus lavaretus) and lake minnows (Eupallasella percnurus), and farmed species such as sturgeons, carp, and numerous salmonid species. Additionally, we delineate projects that support such endeavors. Recent milestones in the establishment of fish sperm cryobanks in Poland catering to both wild and farmed species, including carp and rainbow trout (Oncorhynchus mykiss) – the most economically significant fish in Poland were presented. We also expound on the implementation of cryopreserved semen from sex-reversed rainbow trout in hatchery practices. Furthermore, we discuss significant challenges pertaining to sperm banking, particularly concerning funding and the practical utilization of cryostored semen samples for egg fertilization under hatchery conditions

A brief exposure to low pH prior to refrigerated storage reduces the motility and viability of goldfish sperm (Carassius auratus, Linnaeus, 1758)

Optimal conditions of short-term storage of fish sperm are important for successful artificial reproduction protocols or incubation of sperm in a cryoprotecting medium for successful sperm cryopreservation. The influence of acid or alkaline incubating conditions on short term storage of goldfish sperm was investigated in a series of experiments. Goldfish sperm was diluted an immobilizing solution (1: 3) and incubated for 1 h in acidic, pH 6.5 (AC group) or alkaline, pH 8.5 (AL group) conditions. Subsequently, the sperm of both groups was further diluted (1: 3) in the immobilizing solution and the pH was adjusted to pH 7.51 (±0.02) and 7.56 (±0.07) in the AC and AL group respectively. The samples were kept in sealed bags and stored at 4°C. Viability (%) and motility (%) was estimated in samples obtained daily for the next 4 days. The results indicate that even a brief exposure of sperm to acid acidic conditions prior to storage accelerated the decline of sperm viability and motility during refrigeration

Early postovulatory aging reveals the first proteomic markers of egg quality in pikeperch

This study explored the molecular mechanisms underlying egg quality deterioration due to in vivo postovulatory aging in pikeperch (Sander lucioperca L.), a key species in aquaculture. We employed tandem mass tag (TMT) peptide labeling coupled with LC–MS/MS quantitative proteomics to analyze eggs collected at various postovulation intervals. Our research revealed four distinct proteomic markers (Gins4, Atrx, DnaJB14, and Mrpl10) that are differentially expressed in response to early aging, shedding light on their potential roles in DNA replication, chromatin organization, protein folding, and mitochondrial function. The study confirmed that eggs maintain morphological integrity up to 5 h postovulation but exhibit compromised fertilization capacity, underscoring the importance of timely egg utilization in aquaculture practices. These findings enhance the understanding of egg aging at the molecular level, offering insights for improving reproductive success and larval quality in pikeperch aquaculture. The data are available via ProteomeXchange with the identifier PXD048349

Sperm motility in fish: technical applications and perspectives through CASA systems

[EN] Although a relatively high number of sperm quality biomarkers have been reported over the years in several fish species, sperm motility is nowadays considered the best biomarker for fish spermatozoa. The first scientific reports focusing on fish sperm motility date from a century ago, but the objective assessment allowed by computer-aided sperm analysis (CASA-Mot) systems was not applied to fish species until the mid-1980s. Since then, a high number of sperm kinetic parameters from more than 170 fish species have been reported in more than 700 scientific articles, covering a wide range of topics, such as sperm physiology, sperm storage, broodstock management, the phenomenon of sperm competition, ecotoxicology and understanding the life cycle of the species. The sperm kinetic parameters provided by CASA-Mot systems can serve as powerful and useful tools for aquaculture and ecological purposes, and this review provides an overview of the major research areas in which fish sperm motility assessment by a CASA-Mot system has been used successfully.This writing of this manuscript as received funding from the European Union's Horizon 2020 Research and Innovation program under the Marie Sklodowska-Curie Grant Agreement No. 642893 (ETN IMPRESS). V. Gallego has a postdoctoral grant from the Universitat Politecnica de Valencia (PAID-10-16).Gallego Albiach, V.; Asturiano Nemesio, JF. (2018). Sperm motility in fish: technical applications and perspectives through CASA systems. Reproduction Fertility and Development. 30(6):820-832. https://doi.org/10.1071/RD17460S82083230

Fish sperm motility assessment as a tool for aquaculture research, a historical approach

[EN] Fish sperm motility is nowadays considered the best biomarker for the quality of fish spermatozoa, and sperm motion parameters from more than 300 fish species have been reported in more than 1500 scientific articles covering a wide range of topics, from molecular biology to ecology. The most studied topics have been (i) the sperm storage (involving both the use of chilled¿storage protocols for short¿term periods and sperm cryopreservation techniques for long¿term storage), (ii) the sperm physiology (fathom in the spermatozoa activation process and the whole propulsion machinery of the sperm cells) and (iii) the broodstock management (covering aspects such as rearing conditions, dietary requirements or hormonal induction treatments). In addition, other aquaculture and ecological topics, such as (iv) the knowledge of the breeding cycle of the species, (v) the phenomenon of the sperm competition and (vi) ecotoxicological studies for the evaluation of aquatic environments, have also been approached from the evaluation of sperm motion performance. Therefore, fish sperm motility assessment can serve as a potential tool for aquaculture and ecological purposes, covering key topics of fundamental and applied research. This review gives an overview of the major research areas in which fish sperm motility has been applied successfully.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 642893 (IMPRESS). VG has a postdoc grant from the UPV (PAID-10-16).Gallego Albiach, V.; Asturiano Nemesio, JF. (2018). Fish sperm motility assessment as a tool for aquaculture research, a historical approach. Reviews in Aquaculture (Online). 1-28. https://doi.org/10.1111/raq.12253S12