Selected coelomic fluid parameters of sterlet, Acipenser ruthenus L.: effects of light color and photoperiod

Abstract. Light and color have effect physiological aspects of fish such as growth, the neuro-hormonal system, and reproduction. In the present study, the effects of light color and photoperiod on the levels of selected parameters of coelomic fluid (glucose, total protein, cholesterol, calcium, magnesium) of female sterlet (Acipenser ruthenus) were investigated. Thirty-six broodstock were kept in 12 experimental tanks (500 l) for six months. The fish were reared under four different light regimes (two photoperiods of 18L:6D and 6L:18D and two colors -red and blue) at an intensity of 150 Lx (three replicates). Fish reared under the red-long photoperiod had the highest concentration of the selected parameters of the coelomic fluid. Moreover, significant differences were noted in the all the parameters in fish reared under the red-long photoperiod in comparison with fish from the other treatments (P < 0.05). The results indicate that light (color and photoperiod) influences egg quality during the final stage of A. ruthenus reproduction

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

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

Amino acid sequence control of protein folding and assembly

The amino acid sequence of a linear polypeptide chain contains the information necessary to achieve the native three-dimensional structure of a protein, though the mechanism by which this is accomplished is still not totally understood. The challenge of understanding the nature of protein grammar in terms of the final structure is of paramount interest as many disease are related to misfolding and aggregation of proteins. Using preexisting genetic variants of phage P22 coat protein which are defective in protein folding and have impaired assembly, I isolated additional amino acid substitutions that were capable of alleviating the folding and assembly defects of temperature-sensitive-folding ( tsf) mutants. I identified several different groups of second site suppressors, each of which may potentially reveal different mechanisms by which folding and assembly defects may be corrected. Interestingly, one group of amino acid substitutions, known as global suppressors, are capable of alleviating the folding defects of numerous tsf mutants. Our characterization of the mechanism by which the global suppressors alleviate the original tsf phenotype in coat protein has shown that folding defects in large oligomeric proteins can be suppressed by an increase in the rate and yield of assembly. Perhaps this could be a general mechanism utilized to correct folding defects in large multimeric proteins.