Publications by authors named "Martinez-Pastor F"

Germplasm banking is a fundamental tool for the preservation of autochthonous breeds. Semen cryopreservation is effective for this task, but protocols are adapted to commercial species, and post-thawing sperm quality could be sensitive to environmental cues. We compared the post-thawing sperm quality in doses from the CBA-SERIDA bank in northern Spain for the Asturiana de la Montaña (AM) and Asturiana de los Valles (AV) autochthonous cattle breeds.

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Chromatin status is critical for sperm fertility and reflects spermatogenic success. We tested a multivariate approach for studying pig sperm chromatin structure to capture its complexity with a set of quick and simple techniques, going beyond the usual assessment of DNA damage. Sperm doses from 36 boars (3 ejaculates/boar) were stored at 17 °C and analyzed on days 0 and 11.

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Artificial insemination (AI) is critical for breeding in the dairy industry. High-merit bulls can present low freezability, hampering genetic dissemination. Thawed semen can be improved using density gradient centrifugation (DGC) with colloids, but little information deals with the pre-freezing application.

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The effectiveness of rabbit-sperm cryopreservation is still below average compared to other domestic species. After the sperm cryopreservation process, post-thawing parameters like motility and membrane integrity are significantly compromised. The use of new extender constituents is an approach that can be used to improve the effectiveness of cryopreservation.

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Bull spermatozoa depend equally on glycolysis and oxidative phosphorylation for the maintenance of the energy necessary for their proper functioning. The aim of the present work was to delineate the mitochondrial activity of bull spermatozoa after incubation with specific inhibitors of the different mitochondrial complexes and evaluate their ROS production. Thawed bull sperm cells (30 × 10 mL in Tyrode's extender) were incubated 1 and 3h at 37 °C with rotenone 5 μM (ROT), complex I inhibitor; dimethyl-malonate 10 mM (DMM), complex II inhibitor; carbonyl cyanide m-chlorophenyl hydrazine 5 μM (CCCP), uncoupling agent; antimycin A 1 μg/mL (ANTI), complex III inhibitor; oligomycin 5 μM (OLIGO), ATP synthase inhibitor, and 0.

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Taxifolin is a plant flavonoid effective as an antioxidant. This study aimed to assess the effect of adding taxifolin to the semen extender during the cooling period before freezing on the overall post-thawing sperm variables of Bermeya goats. In the first experiment, a dose-response experiment was performed with four experimental groups: Control, 10, 50, and 100 μg/ml of taxifolin using semen from 8 Bermeya males.

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Semen cryobanks are critical for preserving autochthonous and rare breeds. Since sperm cryopreservation has been optimized for commercial breeds, non-commercial ones (often endangered) must be characterized to ensure the germplasm's viability. This study reports an investigation of the "Asturiana de la Montaña" breed (AM), a valuable Spanish autochthonous cattle breed adapted to the mountainous Atlantic environment.

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Single-layer centrifugation (SLC) with a low-density colloid is an efficient method for removing contaminating microorganisms from boar semen while recovering most spermatozoa from the original sample. This study tested the performance of this technique, using 50-ml tubes, by spiking commercial semen doses prepared without antibiotics with selected bacterial species followed by storage at 17 °C. The doses were spiked up to 10/ml CFU (colony forming units) of the bacteria Burkholderia ambifaria, Pseudomonas aeruginosa, and Staphylococcus simulans.

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Semen cryopreservation in bovine livestock is well established, but logistics often require deviations from standard protocols. Extending the equilibration time to the following day is convenient in many situations. To improve our knowledge of the effects of this modification, we studied the post-thawing and post-incubation (4 h, 38 °C) sperm quality after freezing with 4 or 24-h extension in the OPTIXcell extender by using an ample panel of analyses: CASA for motility; flow cytometry for viability, physiology, oxidative stress, and chromatin parameters (DNA fragmentation, chromatin compaction, and thiol groups status); and spectrometry for malondialdehyde production.

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The storage of boar semen samples at 17 °C for artificial insemination (AI) doses enables the proliferation of the bacteria, making antibiotics necessary. This can contribute to the development of antimicrobial resistance (AMR). This study tested bacterial presence and sperm chromatin structure after using a low-density colloid (Porcicoll) as an antibiotic alternative to eliminate bacteria.

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Melatonin is crucial in reproduction due its antioxidant, hormonal, and paracrine action. Melatonin membrane receptors (MT/MT) have been confirmed on spermatozoa from several species, but functionality studies are scarce. To clarify their role in ruminants as reproductive models, bull (, non-seasonal) and red deer (, highly seasonal) spermatozoa were analyzed after 4 h of incubation (38 °C, capacitating media) in 10 nM melatonin, MT/MT agonists (phenylmelatonin and 8M-PDOT), and antagonists (luzindole and 4P-PDOT).

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Melatonin affects sperm physiology, possibly through membrane receptors. Effects were tested at low concentrations (1 pM, 100 pM, 10 nM and 1 µM) in red deer epididymal spermatozoa as a model for high-seasonality species. Samples were incubated with melatonin as uncapacitated or capacitating conditions (heparin) and evaluated for motility and physiology (flow cytometry).

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Sperm capacitation is a stepwise complex biochemical process towards fertilization. It includes a crucial early calcium (Ca) transport mediated by CatSper channels and Canonical Transient Potential Channels (TRPC). We studied the relative abundance of mRNA transcripts changes of the β, γ and δ subunits and -channels 1, 3, 4, 6 and 7 in pig spermatozoa, after triggering in vitro capacitation by bicarbonate ions at levels present in vivo at the fertilization site.

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Equine spermatozoa highly rely on oxidative phosphorylation for their energy management. The present work aimed to characterize the role of mitochondria on horse sperm motility and ROS production by incubating spermatozoa with specific inhibitors of the different mitochondrial complexes. Equine spermatozoa were incubated 1 h and 3 h at 37 °C with: complex I inhibitor rotenone (5 μM, ROT), complex II inhibitor dimethyl-malonate (10 mM, DMM), complex III inhibitor antimycin A (1.

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The Iberian pig is an autochthonous breed from the Iberian Peninsula highly valued for its meat. The sows are often bred as Iberian × Duroc crossings for increased efficiency. Since sow parity and season affect the reproductive performance, we evaluated two-year records from a commercial farrow-to-finish farm (live, stillborn, and mummified piglets after artificial insemination, AI).

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Suinfort, a commercial semen supplement demonstrated to increase fertility and litter size in commercial sows, was tested to improve reproductive performance in Iberian sows. A total of 1430 Iberian sows were artificially inseminated (AI) with semen from Duroc boars and assigned by parity to receive the seminal additive Suinfort containing 2 IU oxytocin, 5 µg lecirelin, and 2 mM caffeine (SF; = 1713 AI), or to serve as non-supplemented controls (CON; = 2625 AI). CON showed a lower fertility comparing to winter for spring ( = 0.

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The study of sperm subpopulations spans three decades. The origin, meaning, and practical significance, however, are less clear. Current technology for assessing sperm morphology (CASA-Morph) and motility (CASA-Mot) has enabled the accurate evaluation of these features, and there are many options for data classification.

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The effect of time inside the animal's cloaca on sperm quality after hormone-induced spermiation is unknown. However, this knowledge is critical for the development of assisted reproductive biotechnologies in amphibians. Out-of-season spermatozoa were collected from Epidalea calamita for 4h after injection of 10IU g-1 human chorionic gonadotrophin either hourly (Group I (n =10); four samples per male) or every 2h (Group II (n =9); two samples per male).

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Antifreeze proteins (AFP) have the potential for improving sperm cryopreservation. We have applied Type III antifreeze protein (AFP3) on the cryopreservation of spermatozoa from broiler breeder roosters, aiming to enhance post-thawing quality and fertility. Semen was extended at 37°C in Lake's extender containing AFP3 at 0.

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Genetic resource banks (GRB) preserve the genetic material of endangered, valuable individuals or genetically relevant breeds. Semen cryopreservation is a crucial technique to reach these goals. Thus, we aimed to assess the sperm parameters of semen doses from the native pig breed Gochu Asturcelta stored at the GRB of Principado de Asturias (GRB-PA, Gijón, Spain), focusing on intrinsic and extrinsic (boar, season) factors.

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Semen cryopreservation is routine in cattle, but the results of artificial insemination need improvement. A strategy to these aims is the supplementation of the freezing extender with novel antioxidants. This study aimed at testing the natural antioxidants curcumin and crocin as supplements to the commercial extender BIOXcell for freezing semen from 8 Holstein bulls.

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Seminal plasma has gained attention in the last decades, developing from being a mere vehicle for spermatozoa delivery to the female to having a pivotal role in fertility and offspring well-being [...

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Artificial insemination (AI) with cryopreserved semen is still unreliable for extensive pig industry application. Adding seminal plasma (SP) could improve post-thawing quality, but its suitability could vary. We applied a simple cold-shock test (CST, 5 min at 0 °C) on neat semen for classifying ejaculates ( = 63) as resistant or sensitive, obtaining two SP pools (CST-resistant: SPr, sensitive: SPs).

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Poloxamer and hydroxyethyl starch have cytoprotective effects. In the present study, effectiveness was evaluated of these compounds as a cryoprotectant for rooster semen. In Experiment 1 (E1), poloxamer 188 (1%, P188), poloxamer 407 (1%, P407), and control groups were compared after sperm cryopreservation.

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Antibiotics are added to semen extenders to control the growth of bacteria contaminating semen during collection but may contribute to the development of antibiotic resistance. An alternative would be physical separation of spermatozoa from bacteria. The objective of the present study was to evaluate two low densities of Porcicoll for removal of bacteria, and for their effect on sperm recovery and sperm quality.

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