The subpopulation pattern of eel sperm is affected by post-activation time, hormonal treatment and thermal regime

[EN] There has been a marked reduction in natural stocks of eels (genus Anguilla) over the past 60 years, and the culture of eels is still based on the capture of very large quantities of juveniles. It is necessary to close the life cycle in captivity in order to ease the pressure on wild populations. The aims of the present study were to evaluate sperm subpopulations (through cluster analysis of computer-aided sperm analysis data) in the European eel (Anguilla anguilla) and to assess the effects of motility acquisition time after activation (i.e. at 30, 60 and 90 s), the thermal regimen (i.e. 10 degrees C (T10) or 15 degrees C (T15) and up to 20 degrees C, or constant at 20 degrees C (T20)) and hormonal treatments (i.e. human chorionic gonadotropin (hCG), recombinant (r) hCG or pregnant mare serum gonadotropin (PMSG)) on these subpopulations. In all cases, we obtained three subpopulations of spermatozoa: low velocity and linear (S1); high velocity with low linearity (S2); and high velocity and linear (S3; considered high quality). Total motility and S1 were affected by acquisition time; thus, 30 s is recommended as the standard time for motility acquisition. When eels were kept at 20 degrees C (T20), motility data fitted quadratic models, with the highest motility and proportion of S3 between Weeks 8 and 12 after the first injection. Lower temperatures (T10, T15) delayed spermiation and the obtaining of high-quality spermatozoa (S3), but did not seem to alter the spermiation process (similar subpopulation pattern). Conversely, the hormonal treatments altered both the dynamics of the subpopulation pattern and the onset of spermiation (with PMSG delaying it). Total motility and the yield of S3 with the widely used hCG treatment varied throughout the spermiation period. However, using rhCG allowed us to obtain high-quality and constant motility for most of the study (Weeks 7-20), and the S3 yield was also higher overall (61.8 +/- 1.3%; mean +/- s.e.m.) and more stable over time than the other hormonal treatments (averaging 53.0 +/- 1.4%). Using T20 and rhCG would be more economical and practical, allowing us to obtain a higher number of S3 spermatozoa over an extended time.This study was funded by the European Community's 7th Framework Program under the Theme 2 'Food, Agriculture and Fisheries, and Bio-technology', grant agreement no. 245257 (PRO-EEL) and Generalitat Valenciana (ACOMP/2012/086). VG and MCV have predoctoral grants from the Spanish Ministry of Economy and Competitiveness (AGL2010-16009) and Universitat Politecnica de Valencia (UPV) PAID Program (2011-S2-02-6521), respectively. DSP was supported by a contract cofinanced by Ministry of Science and Innovation (MICINN) and UPV (PTA2011-4948-I). FM-P was supported by the Ramon y Cajal program (MICINN, RYC-2008-02560).Gallego Albiach, V.; Vilchez Olivencia, MC.; Peñaranda, D.; Pérez Igualada, LM.; Herraez, MP.; Asturiano Nemesio, JF.; Martinez-Pastor, F. (2015). The subpopulation pattern of eel sperm is affected by post-activation time, hormonal treatment and thermal regime. Reproduction, Fertility and Development. 27(3):529-543. https://doi.org/10.1071/RD13198S52954327

Ex vivo exposure to titanium dioxide and silver nanoparticles mildly affect sperm of gilthead seabream (Sparus aurata) - A multiparameter spermiotoxicity approach

Nanoparticles (NP) are potentially repmtoxic, which may compromise the success of populations. However, the reprotoxicity of NP is still scarcely addressed in marine fish. Therefore, we evaluated the impacts of environmentally relevant and supra environmental concentrations of titanium dioxide (TiO2: 10 to 10,000 mu g.L-1) and silver NP (Ag: 0.25 to 250 mu g.L-1) on the sperm of gilthead seabream (Sparus aurata). We performed short-term direct exposures (ex vivo) and evaluated sperm motility, head morphometry, mitochondrial function, antioxidant responses and DNA integrity. No alteration in sperm motility (except for supra environmental Ag NP concentration), head morphometry, mitochondrial function, and DNA integrity occurred. However, depletion of all antioxidants occurred after exposure to TiO2 NP, whereas SOD decreased after exposure to Ag NP (lowest and intermediate concentration). Considering our results, the decrease in antioxidants did not indicate vulnerability towards oxidative stress. TiO2 NP and Ag NP induced low spermiotoxicity, without proven relevant ecological impacts.info:eu-repo/semantics/publishedVersio

Assessment of parental contributions to fast- and slow-growing progenies in the sea bream Sparus aurata L. using a new multiplex PCR

Molecular tools to assist breeding programs in the gilthead sea bream (Sparus aurata L.) are scarce. A new multiplex PCR technique (OVIDORPLEX), which amplifies nine known microsatellite markers, was developed in this work. This multiplex system showed a high mean heterozygosity (>0.800) and a high mean number of alleles per marker (>14) when tested in two sea bream broodstocks (A: 40 breeders and B: 38 breeders). We tested this multiplex PCR for inferring parentage in a Spanish hatchery that graded the animals by size as part of their management procedure. The progeny of the broodstock were divided into fast- and slow-growth groups. Parentage studies revealed that this management procedure entailed a global reduction of the breeders' representation in progeny and that breeders' contributions were significantly unequal. Due to this, effective sample sizes fell to N ê¿13-14 for fast- and N ê¿18-24 for slow-growth progeny groups. These results imply a 3 to 4% rate of inbreeding per generation in the fast-growth group, which is more important to hatchery managers than the slow group. Not all the progeny were evaluated in this experiment (due to the discarding steps), and thus it is difficult to know if the phenotypic performance showed by the fast-growing progeny will be heritable. However, there were genetic differences between the differentiated growth progeny groups (fast vs. slow, F ST values=0.016 to 0.023; P<0.01). We also identified breeders with significantly different contributions to the fast- (10 breeders) or to the slow- (15 breeders) growth progeny groups. Our results demonstrated that this new multiplex PCR could be useful for quantitative programs (breeding programs, detection of QTL, inbreeding control or reconstruction of fish genealogies) to improve the aquaculture of the gilthead sea bream (S. aurata). © 2011 Elsevier B.V.This work was carried out in collaboration with the fish farm Granja Marina Safor, S.L. (Gandia, Valencia, Spain) and the hatchery Piscicultura Marina Mediterranea, S.L. (Burriana, Castellon, Spain). It was financed by JACUMAR (the PROGENSA project) and the Spanish Ministry of Science and Innovation (MICINN; National Program of Resources and Food and Agriculture Technologies, AGL2006-13411-C03-00, SELECTSPARUS, and AGL2007-64040-C03-00, SELECTBREAM, including European Regional Development Funds). V. Gallego was supported by a FPI scholarship financed by MICINN; C. Garcia-Fernandez was supported by a FPU scholarship financed by MICINN; and I. Mazzeo was supported by a FPI scholarship financed by Generalitat Valenciana. We are indebted to three anonymous referees and the journal editor for valuable comments.Borrell, YJ.; Gallego Albiach, V.; García Fernández, C.; Mazzeo ., I.; Pérez Igualada, LM.; Asturiano Nemesio, JF.; Carleos, CE.... (2011). Assessment of parental contributions to fast- and slow-growing progenies in the sea bream Sparus aurata L. using a new multiplex PCR. Aquaculture. 314(1-4):58-65. https://doi.org/10.1016/j.aquaculture.2011.01.028S58653141-

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

Luteinizing hormone and sexual steroid plasma levels after treatment of European sea bass with sustained-release delivery systems for gonadotropin-releasing hormone analogue

Spermiating male European sea bass Dicentrarchus labrax were treated with gonadotropin-releasing hormone agonists (GnRHa), either a GnRHa injection (IN; 25 μg kg-1 body mass) or one of three types of controlled-release GnRHa-delivery systems: fast release implants (EVAc; 100 μg kg-1), slow release implants (EVSL; 100 μg kg-1) and slow release microspheres (MC; 50 μg kg-1). Luteinizing hormone (LH) release was highly stimulated by all GnRHa treatments, with elevated plasma levels lasting for 2 days in injected fish (IN) and 2, 4 and 6 weeks in controlled-release-treated fish (EVAc, MC and EVSL, respectively), correlating with a 1, 3, 5 and 5 week period of stimulation of milt production, respectively. Plasma levels of the androgens testosterone (T) and 11-ketotestosterone (11-KT), were not significantly affected by the GnRHa treatments. Plasma T was high at early spermiation and declined sharply near the end of this period. Plasma 11-KT levels declined continuously throughout the experiment. Levels of 17,20β-dihydroxy-4-pregnen-3-one (17,20β-P), a proposed maturation-inducing steroid (MIS) in European sea bass, fluctuated around 0.2-1 ng ml-1 and were not greatly affected by the treatments. These results indicated a close correlation between sustained stimulation of LH release, achieved by GnRHa-delivery systems, and long-term enhancement of milt production. They also show an absence of changes in the common sex steroids, associated with elevated LH and enhanced spermiation. © 2002 The Fisheries Society of the British Isles.Work was supported by grants from NATO (ref. CRG94) to M.C. and Y.Z., a Spain-Greek joint Research and Technology Programme (ref. 2000GR0006) to M.C. and C.C.M., and from the European Commission (ref. FAIR CT97-3785) to S.Z.Peer Reviewe

Morphometric characterization of sharpsnout sea bream (Diplodus puntazzo) and gilthead sea bream (Sparus aurata) spermatozoa using computer-assisted spermatozoa analysis (ASMA)

As part of a larger study on sperm quality and cryopreservation methods, the present study characterized the head morphometry of sharpsnout sea bream (Diplodus puntazzo) and gilthead sea bream (Sparus aurata) spermatozoa, using both scanning electron microscopy (SEM) and computer-assisted morphology analysis (ASMA). The latter method has been used rarely in fish and this is its first application on sharpsnout sea bream and gilthead sea bream spermatozoa. Results obtained using SEM are expensive and time-consuming, while ASMA provides a faster and automated evaluation of morphometric parameters of spermatozoa head. For sharpsnout sea bream spermatozoa, similar head measurement values were obtained using both ASMA and SEM, having a mean standard error length, of 2.57 +/- 0.01 mu m vs 2.54 +/- 0.02 mu m, width of 2.22 +/- 0.02 mu m vs 2.26 +/- 0.04 mu m, surface area of 4.44 +/- 0.02 mu m(2) vs 4.50 +/- 0.04 mu m(2) and perimeter of 7.70 +/- 0.02 mu m vs 7.73 +/- 0.04 mu m using ASMA and SEM, respectively. Although gilthead sea bream spermatozoa, were found to be smaller than those of sharpsnout sea bream,,spermatozoal head morphometry parameters were also found to be similar regardless of evaluation method, having a mean head length of 1.97 +/- 0.01 mu m vs 1.94 +/- 0.02 mu m, head width of 1.80 +/- 0.01 mu m vs 1.78 +/- 0.02 mu m, surface area of 3.16 +/- 0.03 mu m(2) vs 3.18 +/- 0.06 mu m(2) and perimeter of 6.52 +/- 0.04 mu m vs 6.56 0.08 mu m using ASMA and SEM, respectively. The results demonstrate that ASMA can be considered as a reliable technique for spermatozoal morphology analysis, and can be a useful tool for studies on fish spermatozoa, providing quick and objective results