Effects of the addition of oocyte meiosis-inhibiting drugs on the expression of maturation-promoting factor components and organization of cytoplasmic organelles.

The present study evaluated the effects of the blockade of meiosis in bovine oocytes by the cyclin-dependent kinase inhibitors roscovitine (ROS) and butyrolactone-I (BL-I) on nuclear maturation and extracellular signal-regulated kinase 1/2 (ERK1/2), cyclin B1 and p34cdc2 protein expression and localization. We also evaluated ultrastructural changes in oocytes. Immature oocytes were obtained from slaughtered bovines and divided into: (1) control (oocytes for in vitro maturation only in tissue culture medium-199 for 24 h), (2) oocytes that were treated with 12.5µMROS for 6 h, (3) oocytes that were treated with 50µMBL-I for 6 h and (4) oocytes that were treated with 6.25 µMROS+25 µMBL-I for 6 h. Incubation with inhibitors was followed by the reversal of blockade for 18 h. Oocytes then underwent immunohistochemical analysis to visualize chromatin and assess ERK1/2, cyclin B1 and p34cdc2 localization/expression, followed by preparation of the cells for ultrastructure analysis by electron microscopy. The groups at 6 h of maturation and before IVM exhibited the lowest number of oocytes in metaphase I. ROS group had the highest number of degenerating oocytes (p < 0.05). After maturation, majority of oocytes were in metaphaseII with no differences among groups (p> 0.05). ERK1/2, cyclin B1 and p34cdc2 expression differed throughout inhibition and oocyte maturation (p < 0.05). No difference was observed in the localization of these proteins in the ooplasm. No ultrastructural changes in oocytes were observed between treatments, with the exception of treatment with drugs that augmented lipid metabolism (p < 0.05). Results indicate that the effects of CDK1 inhibitors are reversible in bovine oocytes, indicated by nuclear, cytoplasmic, and molecular maturation parameters.

Treatment with roscovitine and butyrolactone I prior to in vitro maturation alters blastocyst production.

This study evaluated the effects of oocyte meiosis inhibitors roscovitine (ROS) and butyrolactone I (BL-I) on in vitro production of bovine embryos. Bovine oocytes were maintained in pre in vitro maturation (pre-IVM) with 25 µM ROS or 100 µM BL-I for 24 h to delay meiosis and for 24 h in in vitro maturation (IVM). Following this treatment, the nuclear maturation index was evaluated. All embryos degenerated following this procedure. In the second set of experiments, oocytes were maintained for 6 or 12 h in pre-IVM with the following three treatments: ROS (25 µM or 12.5 µM), BL-I (100 µM or 50 µM) or a combination of both drugs (6.25 µM ROS and 12.5 µM BL-I). Oocytes were cultivated for 18 or 12 h in IVM. When a meiosis-inducing agent was used during pre-IVM for 24 h, more degenerated oocytes were observed at the end of the IVM period. This effect decreased when the meiotic blocking period was reduced to 6 or 12 h. No significant differences were observed in the blastocyst production rate of oocytes in pre-IVM for 6 h with ROS, BL-I, or ROS + BL-I compared with that of the control group (P > 0.05). However, inhibition of oocytes for 12 h resulted in decreased embryo production compared with that in the controls (P < 0.05). There was no difference in the post-vitrification embryo re-expansion rate between the study groups, showing that the meiotic inhibition for 6 or 12 h did not alter the embryo cryopreservation process.

Effect of Using Two Cryopreservation Methods on Viability and Fertility of Frozen Stallion Sperm.

Studies involving different methods and techniques of cryopreservation and its interactions with the conception rates in artificial insemination (AI) programs are reported in the literature. This study evaluated the sperm kinetics, plasma membrane integrity, and fertility rates of mares inseminated with cryopreserved stallion semen subjected to different freezing methods. For this, four ejaculates from five stallions were collected and frozen in conventional (Styrofoam box) or automated system in Mini-Digitcool ZH 400. Seminal samples were evaluated after thawing for sperm motion parameters by CASA and plasma membrane integrity by epifluorescence microscopy. For the fertility trial, a cross-over model was performed using 100 cycles of 50 mares, which were inseminated by one the two freezing methods. No differences were observed for sperm motion parameters and plasma membrane integrity between groups (P > .05). The pregnancy rate using the conventional method was 56% (28/50) and did not differ (P = .5406) from the pregnancy rate (64%, 32/50) obtained using the automatized method. The use of semen from fertile stallions may not illustrate small differences in the two freezing methods evaluated. Conventional and automated freezing systems did not differ in the quality and viability of fertile stallion semen and conception rates, indicating that the two methodologies can be safely used in AI programs.

Diferentes protocolos de congelação de sêmen canino para melhoria de sua cinética e viabilidade / Different canine semen freesing protocols to improve kinetics and viability / Diferentes protocolos de congelación de semen canino para mejoría de su cinética y viabilidad

A maioria dos protocolos utilizados para a criopreservação de sêmen canino, se baseiam em metodologias descritas para outras espécies. Assim, este estudo tem como objetivo avaliar diferentes protocolos de congelação para sêmen desta espécie doméstica. Para tanto, foram utilizados 3 machos, adultos, da raça Buldogue Campeiro, com idades entre 2 a 5 anos e fertilidade comprovada. Foram realizadas 5 colheitas de sêmen de cada animal, pelo método de manipulação digital do bulbo peniano, priorizando a segunda fração do ejaculado. As amostras colhidas foram divididas em 2 grupos, com concentração de 100 x 106 espermatozoides por mL. No grupo 1, as amostras foram diluídas diretamente em meio de congelação comercial Botudog® (Botupharma Biotecnologia Animal). No grupo 2, as amostras foram centrifugadas a 600 g por 10 minutos e em seguida, o pellet foi ressuspendido em meio de congelação comercial Botudog®. As amostras foram envasadas em palhetas de 0,5 mL com concentração de 50 x 106 espermatozoides viáveis. Em seguida, as amostras permaneceram por 1 hora em estabilização a 5ºC. Logo após, transferidas para o vapor de nitrogênio durante 10 minutos, e por fim, mergulhadas em nitrogênio e armazenadas em botijão criogênico. As palhetas foram descongeladas a 46ºC por 15 segundos. Foram avaliados os parâmetros de cinética espermática e integridade de membrana plasmática e acrossomal (IMPA, %). Verificou-se que os parâmetros de motilidade total (%), velocidade linear progressiva (VSL; µm/s), velocidade curvilínea (VCL; µm/s), linearidade (%), percentagem de espermatozoides rápidos (%) e integridade de membrana plasmática e acrossomal avaliados por citometria de fluxo foram superiores no grupo 1, em que as amostras não foram centrifugadas. Estes dados demonstram que, o protocolo para congelação de sêmen canino, utilizando o diluente Botudog®, não preconiza a centrifugação do ejaculado, previamente a congelação.(AU)

Most protocols used for canine semen cryopreservation are based on methodologies described for other species. Thus, this study aims at evaluating different freezing protocols for semen of this domestic species. To this end, 3 adult Bulldog Campeiro males aged 2 to 5 years and proven fertility were used. Five semen samples were collected from each animal using the digital manipulation of the penile bulb method, prioritizing the second fraction of the ejaculate. The collected samples were divided into 2 groups, with a concentration of 100 x 106 sperm per mL. In group 1, the samples were diluted directly into Botudog® commercial freezing medium (Botupharma Animal Biotechnology). In group 2, the samples were centrifuged at 600 g for 10 minutes and then the pellet was resuspended in commercial Botudog® freezing medium. The samples were packed in 0.5 mL straws with a concentration of 50 x 106 viable sperm. Then, the samples remained for 1 hour in stabilization at 5ºC. Afterwards, they were transferred to nitrogen vapor for 10 minutes, and finally, dipped in nitrogen and stored in cryogenic cylinder. The straws were thawed at 46ºC for 15 seconds. Parameters for spermatic kinetics, and plasma and acrosomal membrane integrity (IMPA, %) were evaluated. Total motility (%), progressive linear velocity (VSL; µm/s), curvilinear velocity (VCL; µm/s), linearity (%), percentage of rapid sperm (%) and membrane integrity were found. Plasma and acrosomal samples evaluated by flow cytometry were higher in group 1, where samples were not centrifuged. These data demonstrate that the protocol for canine semen freezing using Botudog® diluent does not recommend centrifugation of the ejaculate prior to freezing.(AU)

La mayoría de los protocolos utilizados para la criopreservación de semen canino se basan en metodologías descritas para otras especies. Por lo tanto, esta investigación tiene como objetivo evaluar diferentes protocolos de congelación para el semen de esta especie doméstica. Con este fin, se utilizaron 3 machos, adultos, de la raza Bulldog Campero, con edades entre 2 a 5 años y fertilidad comprobada. Se realizaron cinco recolecciones de semen de cada animal mediante el método de manipulación digital del bulbo del pene, priorizando la segunda fracción de la eyaculación. Las muestras recolectadas se dividieron en 2 grupos, con una concentración de 100 x 106 espermatozoides por mL. En el grupo 1, las muestras se diluyeron directamente en medio de congelación comercial Botudog® (Botupharma Animal Biotechnology). En el grupo 2, las muestras fueron centrifugadas a 600 g durante 10 minutos y luego el pellet fue resuspendido en medio de congelación comercial Botudog®. Las muestras se envasaron en paletas de 0,5 mL con una concentración de 50 x 106 espermatozoides viables. Luego, las muestras permanecieron durante 1 hora en estabilización a 5ºC. Posteriormente, se transfirieron al vapor de nitrógeno durante 10 minutos y, finalmente, se sumergieron en nitrógeno y se almacenaron en un cilindro criogénico. Las paletas se descongelaron a 46ºC durante 15 segundos. Se han evaluado los parámetros de la cinética espermática y la integridad de la membrana plasmática acrosomal (IMPA, %). Se verificó que los parámetros de motilidad total (%), velocidad lineal progresiva (VSL; µm/s), velocidad curvilínea (VCL; µm/s), linealidad (%), porcentaje de espermatozoides rápidos (%) e integridad de la membrana plasmática y acrosomal evaluadas por citometría de flujo, fueron mayores en el grupo 1, donde las muestras no fueron centrifugadas. Estos datos demuestran que, el protocolo para la congelación de semen canino, usando el diluyente Botudog®, no preconiza la centrifugación del eyaculado, previamente a la congelación.(AU)

Efeito da adição de antioxidantes sobre a viabilidade do sêmen bovino / Addition of antioxidants on the feasibility of bovine semen / Efecto de la adición de antioxidantes bajo la viabilidad del semen bovino

Os antioxidantes atuam no combate aos efeitos nocivos provocados pelos radicais livres, proporcionando melhor qualidade do sêmen fresco e criopreservado. As mudanças de temperatura provocadas durante os processos de congelação e descongelação são responsáveis pelos danos aos espermatozoides, alterando sua viabilidade e fertilidade. O estudo dos antioxidantes, os quais constituem a primeira linha de combate às espécies reativas de oxigênio (EROs), para a melhora da qualidade do sêmen criopreservado, torna-se de fundamental importância, para desenvolvimento de protocolos padrões e aplicáveis, uma vez que existem muitas controvérsias em relação ao tipo de molécula antioxidante e às doses, o momento adequado para ser acrescentado e possíveis alterações destes aos meios de criopreservação. Assim, este trabalho tem como objetivo estudar o efeito dos antioxidantes: catalase, α-tocoferol e piruvato de sódio adicionados em meio diluidor comercial para melhorar a viabilidade do sêmen bovino criopreservado. Inicialmente foram utilizados três touros, da raça Brahman, selecionados de acordo com o escore de condição corporal e exame andrológico. Oito ejaculados foram colhidos por eletroejaculação e imediatamente avaliados a motilidade e o vigor espermático. Em seguida, foram diluídos conforme os grupos experimentais em meio Botubov® (Botupharma Biotecnologia Animal) com adição do antioxidante piruvato de sódio nas concentrações de 1,5 µM, 3 µM e 5 µM e em seguida, as amostras foram congeladas. Numa segunda etapa, serão utilizados outros antioxidantes e concentrações, conforme descrito: 1) Diluidor BotuBov®; 2) Diluidor BotuBov® contendo 7% de crioprotetor e catalase nas concentrações de 20, 80 e 200 UI; 3) Diluidor BotuBov® contendo 7% de crioprotetor e α-tocoferol nas concentrações de 50 µM, 100 µM e 150 µM; 4) Diluidor BotuBov® contendo 7% de crioprotetor e piruvato de sódio nas concentrações de 1,5 µM; 3,5 µM e 5 µM. Após a descongelação do sêmen com a utilização do piruvato, as amostras foram analisadas quanto à motilidade total e progressiva e vigor espermático. Verificou-se que a adição de piruvato de sódio na concentração de 1,5 µM proporcionou uma melhora nos parâmetros de motilidade total e vigor espermático, demonstrando os benefícios de seu uso.(AU)

Antioxidants act in fighting the harmful effects caused by free radicals, providing better quality of both fresh and cryopreserved semen. Changes in temperature caused during the freezing and thawing processes are responsible for damages to the sperm, changing their viability and fertility. The study of antioxidants, which constitute the first line of combat against reactive oxygen species (ROS) to improve the quality of cryopreserved semen, is of utmost importance for the development of standard and applicable protocols, since there are many controversies regarding the type and the doses of antioxidant molecules, the timing for its addition and likely changes to the cryopreservation media. This paper aims at studying the effects of catalase, α-tocopherol, and sodium pyruvate when added to commercial diluent medium to improve the viability of cryopreserved bovine semen. Initially, three Brahman bulls were selected according to the body condition score and andrological examination. Eight ejaculates were collected by electroejaculation, with motility and spermatic vigor being immediately assessed. Subsequently, the samples were diluted according to the experimental groups in Botubov® (Botupharma Animal Biotechnology) medium with the addition of sodium pyruvate at concentrations of 1.5 µM, 3 µM and 5 µM and were subsequently frozen. In a second step, other antioxidants and concentrations will be used, as follows: 1) BotuBov® Diluent; 2) BotuBov® diluent containing 7% cryoprotectant and catalase at concentrations of 20, 80 and 200 IU; 3) BotuBov® diluent containing 7% cryoprotectant and α-tocopherol at concentrations of 50 µM, 100 µM and 150 µM; 4) BotuBov® diluent containing 7% cryoprotectant and sodium pyruvate at concentrations of 1.5 µM; 3.5 µM and 5 µM. After thawing the semen with pyruvate, the samples were analyzed for total and progressive motility and spermatic vigor. It was found that the addition of 1.5 µM sodium pyruvate provided an improvement in total motility and sperm vigor parameters, demonstrating the benefits of its use.(AU)

Los antioxidantes actúan en el combate a los efectos nocivos provocados por los radicales libres, proporcionando mejor calidad del semen fresco y criopreservado. Los cambios de temperatura provocados durante los procesos de congelación y descongelación son responsables por los daños a los espermatozoides, alterando su viabilidad y fertilidad. El estudio de los antioxidantes, que constituyen la primera línea de combate a las especies reactivas de oxígeno (ERO), para la mejora de la calidad del semen criopreservado, se hace de fundamental importancia para el desarrollo de protocolos estándares y aplicables, ya que existen muchas controversias en relación al tipo de molécula antioxidante y a las dosis, el momento adecuado para ser añadido y posibles alteraciones de éstos a los medios de criopreservación. Así, este estudio ha tenido como objetivo estudiar el efecto de los antioxidantes: catalasa, α-tocoferol y piruvato de sodio añadidos en medio diluidor comercial para mejorar la viabilidad del semen bovino criopreservado. Inicialmente se utilizaron tres toros, de la raza Brahman, seleccionados de acuerdo con la puntuación de condición corporal y examen andrológico. Ocho eyaculados fueron recogidos por electroejaculación e inmediatamente evaluados la motilidad y el vigor espermático. A continuación, se diluyeron de acuerdo con los grupos experimentales en medio Botubov (Botupharma Biotecnología Animal) con adición de antioxidante piruvato de sodio a concentraciones de 1,5 µM, 3 µM y 5 µM, y luego las muestras se congelaron. En una segunda etapa, se utilizarán otros antioxidantes y concentraciones, según se describe: 1) Diluidor BotuBov®; 2) Diluidor BotuBov® conteniendo 7% de crioprotector y catalasa en las concentraciones de 20, 80 y 200 UI; 3) Diluidor BotuBov® que contiene 7% de crioprotector y α-tocoferol en las concentraciones de 50 µM, 100 µM y 150 µM; 4) Diluidor BotuBov® conteniendo 7% de crioprotector y piruvato de sodio en las concentraciones de 1,5 µM; 3,5 µM y 5 µM. Después de la descongelación del semen con la utilización del piruvato, las muestras fueron analizadas en cuanto a la motilidad total y progresiva y vigor espermático. Se comprobó que la adición de piruvato de sodio en la concentración de 1,5 µM proporcionó una mejora en los parámetros de motilidad total y vigor espermático, demostrando los beneficios de su uso.(AU)

In vitro embryos production after oocytes treatment with forskolin.

The inhibition of nuclear maturation allows time for the oocyte to accumulate molecules that are important for embryonic development. Thus, the objective of this work was to evaluate the effect of blocking oocyte meiosis with the addition of forskolin, an efficient inhibitor of nuclear maturation, in in vitro maturation (IVM) medium. Forskolin was added to the IVM medium for 6 h at concentrations of 0.1 mM, 0.05 mM or 0.025 mM, then the oocytes were allowed to mature in drug-free medium for 18 h. The oocytes were assessed for the stage of nuclear maturation, the activity and distribution of mitochondria, oocyte ultrastructure, the number of viable cells and the apoptosis rate. After forskolin treatment, the oocytes were fertilized in vitro and cultured for 7 days. On day 7, the blastocyst rate, the ultrastructure, the number of intact cells and the apoptosis rate of the blastocysts were measured. No differences were observed for the stage of nuclear maturation of the oocyte, the mitochondrial activity and distribution, the blastocyst rate or total number of intact cells. However, a higher rate of apoptosis was observed in the blastocysts produced from oocytes blocked for 6 h with the higher concentration of forskolin (P < 0.05). We conclude that all the experimental groups reached the MII stage after the addition of forskolin and that the highest concentration of forskolin caused cellular degeneration without harming embryo production on the 7th day.

Influence of culture medium and age of bovine blastocysts in established colonies of embryonic stem cells.

The objective of this study was to evaluate the potential of bovine IVF blastocysts at different stages of embryonic development in establishing ESC-like. Furthermore, blastocysts cultured in medium containing (10%) and (2.5%) fetal calf serum (FCS) were compared to determine if the serum concentration during in vitro culture alters the blastocyst's potential to establish ESC-like culture. It was observed that only ICM's from expanded blastocysts adhered to the monolayer (n=160) independent of the concentration of serum used during IVF culture. There were no observable differences in potential to establish ESC-like in embryos cultured with 2,5% or 10% FCS . The bFGF didn´t seems to be required for maintenance of bovine ESC-like regardless of culture conditions. Blastocysts and colonies in primary culture and after the first passage were positive for Oct4, Nanog, SSEA-3 and TRA-1-81. Expanded blastocysts gave rise to ESC-like colonies, and the addition of LIF was sufficient to maintain cells undifferentiated in culture.