Efeito da substituição da gema de ovo pela lecitina de soja na criopreservação de sêmen equino

Pós-graduação em Medicina Veterinária - FMVZ

Efeito da exposição aos crioprotetores glicerol e metilformamida sobre a viabilidade e fertilidade do sêmen equino

Pós-graduação em Medicina Veterinária - FMVZ

Características reprodutivas de garanhões mantidos sob luz natural ou contínua, em ambiente tropical

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação de diferentes técnicas de inseminação artificial em éguas utilizando um baixo número de espermatozóides

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo das catelicidinas no plasma seminal de garanhões e das interleucinas na resposta inflamatória pós-iseminação artificial em éguas

Pós-graduação em Medicina Veterinária - FMVZ

Improved sperm cryosurvival in diluents containing amides versus glycerol in the Przewalski's horse (Equus ferus przewalskii)

Two studies were conducted to understand sperm cryosensitivity in an endangered equid, the Przewalski's horse (Equus ferns przewalski), while testing the cryoprotectant ability of formamides. The first assessed the toxicity of permeating cryoprotectants (glycerol, methylformamide IMF] and dimethylformamide [DMF]) to Przewalski's horse spermatozoa during liquid storage at 4 C. The second examined the comparative influence of three diluents (with or without formamides) on cryosurvival of sperm from the Przewalski's versus domestic horse. When Przewalski's horse spermatozoa were incubated at 4 C in INRA 96 with differing concentrations of glycerol, MF or DMF or a combination of these amides, cells tolerated all but the highest concentration (10% v/v) of MF alone or in combination with DMF, both of which decreased (P < 0.05) motility traits. There was no effect of cryoprotectants on sperm acrosomal integrity. In the cryosurvival study, average sperm motility and proportion of cells with intact acrosomes in fresh ejaculates were similar (P> 0.05) between the Przewalski's (67%, 84%, respectively) and domestic (66%, 76%) horse donors. Sperm from both species were diluted in lactose-EDTA-glycerol (EQ), Botu-Crio (BOTU; a proprietary product containing glycerol and MF) or SM (INRA 96 plus 2% [v/v] egg yolk and 2.5% [v/v] MF and DMF) and then frozen over liquid nitrogen vapor. After thawing, the highest values recovered for total and progressive sperm motility, acrosomal integrity and mitochondria] membrane potential were 42.4%, 21.8%, 88.7% and 25.4 CN (CN = mean JC-1 fluorescence intensity/cell on a channel number scale), respectively, in the Przewalski's and 49.3%, 24.6%, 88.9% and 25.8 CN, respectively, in the domestic horse. Although sperm progressive motility and acrosome integrity did not differ (P> 0.05) among treatments across species, mitochondrial membrane potential was higher (P< 0.05) in both species using EQ compared to BOTU or SM media. Additionally, Przewalski's stallion sperm expressed higher (P < 0.05) post-thaw total motility in BOTU and SM compared to EQ whereas there were no differences among freezing diluents in the domestic horse. In summary, Przewalski's stallion sperm benefit from exposure to either MF or DMF as an alternative cryoprotectant to glycerol. Overt sperm quality appears similar between the Przewalski's and domestic horse, although the total motility of cells from the former appears more sensitive to certain freezing diluents. Nonetheless, post-thaw motility and acrosomal integrity values for Przewalski's horse spermatozoa mimic findings in the domestic horse in the presence of INRA 96 supplemented with 2% (v/v) egg yolk and a combined 2.5% concentration of MF and DMF. Published by Elsevier Inc.

Use of cholesterol-loaded cyclodextrin: An alternative for bad cooler stallions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Criopreservação de sêmen de epidídimo de garanhões

It is a fact that Brasil has a featured position in the equine market due to the size and the high quality of its squad. To keep the competitivity, the reproduction biotechnologies have a big and important role. The cryopreservation of stallion semen, for example, generates innumerous advantages, which includes: larger number of obtained doses, storing genetic material for undetermined time, using the semen of a good stallion even after its dead or any other event that makes both semen collection and mating impossible, etc. In this context, the cryopreservation of epididymal sperm, has been seen as a promising technique in equine reproduction. The epididymal cauda has a significant quantity of fertile spermatozoa and this ensures a huge store of cells in cases of unexpected accidents, which can early interrupt with the reproductive life of a stallion. Lots of studies are being developed using the cryopreservation of stallion epididymal sperm. These studies permit the propagation of high quality genetic material and make possible for the stallion owner to opt for a final semen collect in unexpected circumstances

Fixed-time insemination with frozen semen in mares: is it suitable for poorly fertile stallions?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Perfil lipídico da membrana plasmática e alterações morfofuncionais de esperamatozóides de garanhões resistentes e sensíveis à criopreservação

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Seletividade de produtos fitossanitários utilizados na cultura da soja para pupas de Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito da adição de butil-hidroxitolueno nos meios de refrigeração e congelação sobre a viabilidade espermática de equinos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo sobre a redução do estresse oxidativo em sêmen equino a partir da adição de quercetina nos diluentes de refrigeração e congelação

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo sobre a redução do estresse oxidativo em sêmen equino a partir da adição de quercetina nos diluentes de refrigeração e congelação

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of bovine sperm cryopreservation using different freezing techniques and cryoprotective agents on plasma, acrosomal and mitochondrial membranes

The success of semen cryopreservation is influenced by several factors, such as freezing curves and cryoprotectants. These two factors are of special interest once they may lead to many important physical-chemical changes resulting in different degrees of damage in spermatozoa structure. This experiment was designed to compare the effect of bull semen cryopreservation using two freezing techniques: conventional (CT cooling rate of -0.55 degrees C min-1 and freezing rate of -19.1 degrees C min-1) and automated (AT cooling rate of -0.23 degrees C min-1 and freezing rate of -15 degrees C min-1), performed with different curves, and with three cryoprotectants (glycerol, ethylene glycol and dimethyl formamide) on bovine sperm motility and integrity of plasma, acrosomal and mitochondrial membranes. These variables were simultaneously evaluated using the fluorescence probes propidium iodide, fluorescein-conjugated Pisum sativum agglutinin and MitoTracker Green FM. The effects of freezing techniques, as well as of different cryoprotectants were analysed by the analysis of variance. The means were compared by Fishers test. There were no significant differences between freezing techniques (P > 0.05). Glycerol showed higher percentages of motility, vigour and integrity of plasma, acrosomal and mitochondrial membranes than other two cryoprotectants (P < 0.05). Ethylene glycol preserved higher motility and integrity of plasma and mitochondrial membranes than dimethyl formamide (P < 0.05). Sperm motility with glycerol was 30.67 +/- 1.41% and 30.50 +/- 1.06%, with ethylene glycol was 21.17 +/- 1.66% and 21.67 +/- 1.13% and with dimethyl formamide was 8.33 +/- 0.65% and 9.17 +/- 0.72% to CT and AT curves, respectively. The percentage of spermatozoa with simultaneously intact plasma membrane, intact acrosome and mitochondrial function (IPIAH) was 14.82 +/- 1.49% (CT) and 15.83 +/- 1.26% (AT) to glycerol, 9.20 +/- 1.31% (CT) and 9.92 +/- 1.29% (AT) to ethylene glycol 4.65 +/- 0.93% (CT) and 5.17 +/- 0.87% (AT) to dimethyl formamide. Glycerol provided the best results, although nearly 85% of spermatozoa showed some degree of injury in their membranes, suggesting that further studies are required to improve the results of cryopreservation of bovine semen.