Toll-like receptor expression in C3H/HeN and C3H/HeJ mice during Salmonella enterica serovar Typhimurium infection

Here, we have investigated the mRNA expression of Toll-like receptor 2 (TLR-2), TLR-4, and MD-2 in spleens and livers of C3H/HeN mice (carrying wild-type TLR-4) and C3H/HeJ mice (carrying mutated TLR-4) in response to Salmonella infection. During Salmonella infections, TLR-4 is activated, leading to increased TLR-2 and decreased TLR-4 expression

Hormonal manipulations for the enhancement of sperm production in cultured fish and evaluation of sperm quality

[EN] This article reviews the use of hormonal treatments to enhance sperm production in aquaculture fish and the methods available for evaluating sperm quality. The different types of testis development are examined and a brief review is presented of the endocrine regulation of spermatogenesis in fishes, including the increasing evidence of the existence of spermatozoa subpopulations. Hormonal manipulations are employed to induce spermatogenesis in species such as the freshwater eels, to synchronize maximal sperm volume to ovulation for in vitro fertilization and to enhance sperm production in species with poor spermiation. The hormones that are employed include gonadotropins (GtHs) of piscine or mammalian origin, and gonadotropin-releasing hormone agonists (GnRHa) administered by injections or controlled-release delivery systems, with or without dopaminergic inhibitors. Pheromones in the culture water and hormones added to the sperm in vitro have also been employed to enhance spermiation and sperm quality, respectively, in some fishes. Hormonal therapies usually do not affect sperm quality parameters, except in cases where fish fail to spermiate naturally or produce very small volumes of high-density sperm. Different parameters have been used to evaluate fish sperm quality, including sperm volume and density, spermatozoa motility and morphometry, and seminal plasma composition. The development of Computer-Assisted Sperm Analysis (CASA) systems made possible the estimation of a higher number of sperm motion parameters using an objective, sensitive and accurate technique. The development of Assisted Sperm Morphology Analysis (ASMA) software has introduced a new approach for sperm evaluation studies, demonstrating changes in the spermatozoa related to reproductive season, hormonal treatments or the cryopreservation processes, and how these may be related to changes in sperm motility and fertilization capacity. The article concludes with a few practical protocols for the enhancement of sperm production in aquaculture species.We would like to thank the COST Action FA1205 (AQUAGAMETE) titled “Assessing and improving the quality of aquatic animal gametes to enhance aquatic resources - The need to harmonize and standardize evolving methodologies, and improve transfer from academia to industry” for initiating the production of this special issue and funding partially this article. JFA has been partly funded by the Spanish Ministry of Economy and Competitiveness (REPRO-TEMP; AGL2013-41646-R) and the European Training Network IMPRESS (Marie SklodowskaCurie Actions; Grant agreement n°: 642893). ND has been funded partly by the INIA-FEDER project RTA2011-00050, and CCM and ND have been supported also by the EU project DIVERSIFY (7FP-KBBE-2013-GA 602131).Mylonas, CC.; Duncan, NJ.; Asturiano Nemesio, JF. (2017). Hormonal manipulations for the enhancement of sperm production in cultured fish and evaluation of sperm quality. Aquaculture. 472:21-44. https://doi.org/10.1016/j.aquaculture.2016.04.021S214447

Sperm contamination by urine in Senegalese sole (Solea senegalensis) and the use of extender solutions for short-term chilled storage

Methods are needed to manage the sperm of Senegalese sole (Solea senegalensis), which will enable the industry to use artificial fertilisation to reproduce hatchery raised sole and implement breeding programs. The present study aimed to (a) describe the male reproductive and urinary system, (b) describe the effects of urine contamination on sperm quality and (c) examine the use of extenders for short term chilled storage of sole sperm. Nine males were dissected to describe the male reproductive and urinary system. A total of 49 males were examined and 32 (65.3%) provided adequate sperm samples of the study. Initially the samples were described by appearance (colour, transparency and fluidity) and sub-samples analysed for sperm quality, urea concentration, osmolality, pH and protein concentration. Cell concentration and sperm quality parameters, percentage motility, curvilinear velocity (VCL) and average path velocity (VAP), were measured using ImageJ CASA. Control samples and samples diluted (1:3) in six different extender solutions (modified Leibovitz, Ringer, NAM, Sucrose, Stor Fish® and Marine Freeze®) were stored short-term (4 °C) and tested zero, three, six and 24 h after collection. The close proximity of the reproductive and the urinary systems, especially the sperm ducts being attached to the urinary bladder makes obtaining sperm without urine contamination appear difficult. All the samples appeared to be contaminated with urine. Samples that appeared to be contaminated with urine (yellow colour) had similar spermatozoa cell concentration and urea concentration as samples that appeared not to be contaminated with urine (whitish colour), although motility was significantly lower in yellow samples. Seminal plasma urea concentration was positively correlated with osmolality. Cluster analysis grouped samples with significantly higher sperm quality and pH and significantly lower urea concentration and osmolality to indicate that urine contamination negatively affected sperm quality by increasing osmolality and decreasing pH. Amongst the six extender solutions Leibovitz and Marine Freeze® preserved significantly higher percentage motility 24 h after collection. Ringer, NAM and Stor Fish® were intermediate and Sucrose was similar to control samples that significantly decreased motility 3 h after collection. Taken together all sole sperm samples probably had urine contamination, which is difficult or impossible to avoid especially if all the sperm available needs to be collected. The extenders, Leibovitz and Marine Freeze® were used to maintain sperm quality and mitigate the negative effects of urine contamination. The collection and short term chilled storage in extenders of sole sperm from the majority of males in a broodstock (65.3%) can provide a valid sperm management system for industrial application for artificial fertilisation, however, further work is needed.info:eu-repo/semantics/acceptedVersio

The presence of wild Senegalese sole breeders improves courtship and reproductive success in cultured conspecifics

The life cycle of Senegalese sole (Solea senegalensis) is not closed in captivity due to a reproductive dysfunction related to the lack of participation of cultured male breeders in the courtship. To discern a possible solution to this social reproductive dysfunction, the main objective of this study was to determine the effect of the presence of spawning wild Senegalese sole breeders on the courtship and reproduction of cultured breeders. Three experimental groups were formed: Control group (n = 10) formed with only cultured sole; groups M1 and M2 constituted of mixed-origin sole (10 cultured and 8 or 9 wild breeders). All cultured breeders were from the same stock, which had never successfully reproduced, whilst the wild broodstock had spawned viable eggs in captivity. All groups were held in the same captive conditions and spawning, and behaviour were recorded for each group over four spawning seasons. All spawns were collected, and the parameters registered were floating and non-floating eggs, fertilization and hatching rates. In addition, parental analysis was made of larvae from viable spawns. Behaviour was studied with video recordings to compare locomotor activity and courtship behaviours including the "Follow" behaviours where sole swim after each other in a procession. Fertilized spawns were obtained from the mixed-origin groups (M1 and M2) including spawns involving a cultured male. The cultured males also participated actively in the "Follow" behaviours with the courting wild sole and this participation of cultured males increased significantly over the four years of the experiment. Male percentage participation in the "Follow" behaviours was positively correlated (R = 0.81) to participation in spawning to indicate the importance of increasing cultured male participation in the "Follow" behaviours. A total of seven spawns were obtained from a cultured male that fertilized eggs from one cultured female and two wild females. The same cultured female also spawned with a wild male. No viable spawns were obtained from the Control group and locomotor activity and courtship behaviour counts were significantly lower than in the experimental mixedorigin groups. This is the first report of cultured male breeders participating in reproductive behaviour and spawning, which could be associated with social learning processes, mate selection and dominance where cultured males copied the behaviour and spawning of wild Senegalese sole breeders.Spanish National Institute for Agronomic Research (INIA)-FEDER [RTA201100050, RTA2014-00048]FCT - Foundation for Science and TechnologyPortuguese Foundation for Science and Technology [UID/Multi/04326/2019]info:eu-repo/semantics/submittedVersio