Abstract Since bull fertility prediction remains challenging, the identification of potential fertility markers is important considering the economic benefits to the livestock industry. The main goal of this study was to determine the Na/K-ATPase activity and expression in thawed sperm of high (HF)- and low-fertility (LF) Angus bulls. Samples from three different batches/bulls with HF (n = 4) and LF (n = 4) were used. The Na/K-ATPase activity was determined after thawing, whereas sperm kinematics, membrane integrity, and expression of Na/K-ATPase on sperm surface were evaluated immediately post-thaw and after 120 minutes of incubation. Within the same incubation time, there was no difference on sperm membrane integrity, kinematics, and the expression of Na/K-ATPase on the sperm surface between HF and LF bulls. Kinematic parameters of LIN and VCL were not influenced by incubation time in samples from HF and LF, respectively. A tendency (P = 0.06) of higher Na/K-ATPase enzymatic activity for sperm of HF bulls compared to LF bulls was observed (0.49 ± 0.07 and 0.32 ± 0.06, respectively). In conclusion, Na/K-ATPase activity and expression in thawed sperm from Angus bulls are not related to the fertility index after fixed-time artificial insemination. However, sperm kinematics related to hyperactivation might indicate higher sperm cryotolerance for HF bulls.

Abstract Although equine blastocysts ≤ 300 µm in diameter can be successfully vitrified, larger equine blastocysts are not good candidates for cryopreservation. As Na+, K+-ATPase is involved in maintaining blastocyst expansion, perhaps inhibition of this enzyme would be a viable method of reducing blastocyst diameter prior to cryopreservation. Objectives were to evaluate effects of ouabain-induced inhibition of Na+, K+-ATPase in equine blastocysts. Sixteen mares were ultrasonographically monitored, given deslorelin acetate to induce ovulation, and inseminated. Embryos (D7 and D9) were harvested and Na+, K+-ATPase inhibited for 1 or 6 h by exposure to 10-6 M ouabain, either natural ouabain or conjugated to fluorescein (OuabainFL), during incubation at 37° C. Evaluations included morphometric characteristics (bright field microscopy) and viability (Hoescht 33342 + propidium iodide). Blastocysts incubated for 6 h in Holding medium + ouabain (n=3) had, on average, a 45.7% reduction in diameter, with adverse morphologic features and no re-expansion after subsequent incubation in Holding medium for 12 h. In subsequent studies, even a 1-h exposure to Ouabain or OuabainFL, caused similar reductions, namely 38.7 ± 6.7% (n=5) and 33.6 ± 3.3% (n=7) for D7 and D9 blastocysts, respectively. Ouabain binding was confirmed after OuabainFL exposition and all embryos (n=12) lost viability. We concluded that Na+, K+-ATPase inhibition with ouabain caused death of equine blastocysts and therefore was not a viable method of reducing blastocyst size prior to cryopreservation.

Abstract The objective of this study was to investigate the need of seminal plasma removal for short-term cooling of buck semen in soybean lecithin (SL) based extender. Each pool was divided equally, and one half was subjected to centrifugation to remove seminal plasma (SP-), while the other half remained with seminal plasma (SP+). Then, both SP+ and SP- samples were diluted in two SL extenders (extender A = 1% SL; extender B = 2% SL), cooled to 5ºC and stored for 48 hours. The sperm kinetics, evaluated by CASA, and plasma membrane integrity (PMI), acrosomal integrity (ACI) and high mitochondrial membrane potential (HMMP), evaluated by epifluorescence microscopy, were determined within five minutes after reaching 5°C (T0), as well as after 24 (T24) and 48 (T48) hours of storage. Interactions (seminal plasma vs. extender vs. time;) were observed for all variables assessed. Total and progressive motility and other variables of sperm kinetics decreased after 24 hours of cooling in the SP+ group, and after 48 hours of storage, these same variables were lower in SP+/B compared to SP-/B groups. Furthermore, SP+ reduced PMI (extender B, T48), HMMP (A and B extenders, T48) and ACI (extender A, T0) compared to SP- samples. The interactions between seminal plasma and soybean lecithin phospholipids seemed to occur in a time-dependent manner. It was concluded that the removal of seminal plasma improves the quality of goat semen that was cooled in a soybean lecithin-based extender, especially when using 2% soybean lecithin.

O objetivo deste estudo foi identificar as proteínas do plasma seminal de caprinos da raça Alpina Americana criados na região Nordeste do Brasil que estão relacionadas ao índice pluviométrico e à qualidade do sêmen. O sêmen foi obtido pelo método de vagina artificial a partir de três reprodutores e foi avaliado quanto aos parâmetros macroscópicos e microscópicos. O perfil de proteínas do plasma seminal foi realizado por eletroforese bidimensional. Os parâmetros volume do sêmen, integridade do acrossoma e proteínas totais evidenciaram diferença significativa (P<0,05) entre os períodos de alto (1,7mL, 90,3% e 372µg mL-1, respectivamente) e baixo (1,2mL, 80,3% e 494µg mL-1, respectivamente) índice pluviométrico. Foram detectados, nos períodos de alto e baixo índice pluviométrico, 47 e 49 spots de proteínas com massa molecular relativa de 4 a 106kDa e de 15 a 97kDa e ponto isoelétrico de 3,00 a 8,96 e de 4,48 a 9,83, respectivamente. Apenas no período de alto índice pluviométrico foram observados os grupo de proteínas de 13kDa e 45kDa. Conclui-se que o sêmen de caprinos da raça Alpina Americana criados na região Nordeste do Brasil apresenta-se com melhor qualidade quando colhido no período de alto índice pluviométrico, o que pode ser atribuído à presença das proteínas de 13kDa e 45kDa.

The aim of this study was to identify proteins in seminal plasma of goats raised in the Northeast of Brazil related with precipitation index and semen quality. Semen was obtained from three bucks and evaluated to the microscopic and macroscopic parameters. The profile of seminal plasma proteins was performed by analysis of two-dimensional electrophoresis. Volume, acrosome integrity and total proteins had significant difference (P<0.05) between the periods of high (1.7mL, 90.3% and 372g mL-1, respectively) and low (1.2mL, 80.3% and 494µg mL-1, respectively) precipitation index. It was detected during high and low precipitation index, 47 and 49 spots of proteins with molecular weight of 4 to 106kDa and 15 to 97kDa, and isoelectric point of 3.00 to 8.96, and 4.48 to 9.83, respectively. Only in the period of high precipitation index were observed groups of proteins with 13kDa and 45kDa. It can be concluded that semen of Alpine American goats raised in the Northeast of Brazil has best quality when obtained in the period of high precipitation index, which can be attributed to the presence of protein with 13kDa and 45kDa.