Follicular size affects the meiotic competence of in vitro matured prepubertal and adult oocytes in sheep

Non-atretic follicles dissected from prepubertal and adult ovaries were allocated in three groups: a) < 1 mm; b) 1-2 mm; c) > 2 mm. After 24 h of maturation, a lower percentage of adult oocytes from group a (P < 0.01) reached metaphase II than those from groups b and c (70.4 versus 89.5 and 95.5). Prepubertal oocytes showed similar results (P < 0.01; 27.2 versus 79.8 and 81.8). There was a significant difference (P < 0.01) in meiotic progression between prepubertal and adult oocytes of < 1 mm follicles. The diameter of prepubertal oocytes derived from group a was significantly lower (P < 0.01) compared to groups b and c (138.1 versus 142.1 and 145.6); adult oocytes showed similar results (P < 0.01; 142.2 versus 157.2 and 158.1 Oocytes with the same diameter derived from different follicles of prepubertal and adult ovaries showed similar meiotic progression rates. Des follicules non-atrétiques sélectionnés à partir d’ovaires d’ovins prépubères et adultes ont été répartis en trois groupes selon leur diamètre : a) < 1 mm ; b) 1-2 mm ; c) > 2 mm. Après 24 h de maturation les ovocytes dérivant des ovaires d’animaux adultes appartenant au groupe a ont atteint la MII dans des pourcentages nettement inférieurs (p < 0,01) à ceux observés pour les groupes b et c (70,4 versus 89,5 et 95,5). Des résultats identiques ont été obtenus avec les ovocytes provenant d’animaux prépubères (p < 0,01 ; 27,2 versus 79,8 et 81,8). Une grande différence (p < 0,01) dans le potentiel à reprendre la méiose existe entre les ovocytes de prépubères et des adultes provenant de follicules < 1 mm. Le diamètre des ovocytes d’agneaux provenant de follicules du groupe a était nettement inférieur (p < 0,01 ) par rapport à ceux provenant de follicules des groupes b ou c (138,1 versus 142,1 et 145,6). Des résultats identiques ont été observés pour les ovocytes provenant d’animaux adultes (p < 0,01, 142,2 versus 157,2 et 158,1). Des ovocytes de même diamètre provenant d’ovaires de prépubères et d’adultes ne diffèrent pas dans leur aptitude à reprendre la méiose

La práctica informacional de los usuarios de un sistema de información a partir de una perspectiva comprensiva

Objetivo. Esta pesquisa se caracteriza como um estudo de usuários do Sistema de Informação da Extensão da Universidade Federal de Minas Gerais (SIEX/UFMG). O objetivo geral do estudo é investigar as práticas informacionais dos usuários deste sistema, contemplando tanto os aspectos comportamentais dos seus usuários quanto os aspectos operacionais do sistema. Método. Os fundamentos teóricos adotados buscaram aporte na literatura sobre (i) comportamento informacional - aproximando a pesquisa dos estudos da abordagem social -, (ii) fenomenologia social - para compreender as práticas informacionais dos usuários – e (iii) critérios de usabilidade - para verificar a percepção dos usuários em relação ao sistema. Ao invés de atribuir razões para o comportamento dos usuários ou estabelecer regras gerais que governem seus hábitos, pretendeu-se compreender as motivações e percepções dos próprios usuários. Para tanto, procurou-se adentrar no universo dos usuários por meio da coleta de dados através de entrevistas semiestruturadas em profundidade. Resultados. Encontrou-se resultados de natureza compreensiva e descritiva, trazendo considerações relevantes acerca do SIEX/UFMG e da extensão na Universidade. Conclusões. A pesquisa revelou que o uso do SIEX/UFMG vai além de suas funções básicas e permitiu compreender a percepção dos usuários em relação à extensão universitária.Objective. This research is characterized as a study of users of the Sistema de Informação da Extensão da Universidade Federal de Minas Gerais (SIEX/UFMG). The general objective of the study is to investigate the information practices of users of the system, covering both the behavioral aspects of their users and the operational aspects of the system. Method. The theory is based on (i) information behavior - approaching this research studies the social approach -, (ii) social phenomenology - seeking to understand users informational practices - and (iii) usability - to verify users perception in relation to the system. Instead of assigning reasons for the users information behavior of users, we search to understand their motivations and perceptions. Therefore, we tried to enter the universe of users by writing in-depth semi-structured interviews to collect data. Results. The research generated good comprehensive and descriptive results, bringing relevant considerations about SIEX/UFMG and extension at the University. Conclusions. The survey revealed that the use of SIEX / UFMG goes beyond its basic functions and allows us to understand the users' perception regarding the university extension.Objetivo. Esta investigación se caracteriza como un estudio de usuarios del Sistema de Información de la Extensión de la Universidad Federal de Minas Gerais (SIEX/UFMG). El objetivo general del estudio es investigar las prácticas informacionais de los usuarios de este sistema, contemplando tanto los aspectos comportamentales de sus usuarios cuanto los aspectos operacionales del sistema. Método. Los fundamentos teóricos adoptados recogieron aporte en la literatura sobre (i) comportamiento informacional - aproximando la investigación de los estudios del abordaje social -, (ii) fenomenologia social - para comprender las prácticas informacionais de los usuarios – y (iii) criterios de usabilidade - para verificar la percepción de los usuarios en relación al sistema. En vez de atribuir razones para el comportamiento de los usuarios o establecer reglas generales que gobiernen sus hábitos, se pretendió comprender las motivaciones y percepciones de los propios usuarios. Para tanto, se buscó adentrar en el universo de los usuarios por medio de la colecta de datos a través de entrevistas semiestruturadas en profundidad.Resultados. Se encontró resultados de naturaleza comprensiva y descriptiva, trayendo consideraciones relevantes acerca del SIEX/UFMG y de la extensión en la Universidad. Conclusiones. La investigación reveló que el uso del SIEX/UFMG va además de sus funciones básicas y permitió comprender la percepción de los usuarios en relación a la extensión universitaria

Production and lambing rate of blastocysts derived from in vitro matured oocytes after gonadotropin treatment of prepubertal ewes

The aim of this study was to evaluate the effect of gonadotropin treatment on the in vitro maturation, blastocyst production, and developmental potential to term of oocytes collected from Sardinian neonatal and prepubertal ewes at 4 to 6 wk of age. Cumulus-oocyte complexes were recovered at 24 h after withdrawal of a 1/6th size progestagenated pessary from the donors, of which each received 120 IU FSH/LH and 400 IU PMSG in a single dose 36 h before sponge removal. Treated donors produced a greater ( P < .01) number of oocytes per animal (86.2 ± 7.9) compared with slaughterhouse (untreated) prepubertal ewes (55.5 ± 6.1) of the same age or with treated neonatal ewes (6.1 ± 0.7) 10 d old. During oocyte maturation, there were no differences in the percentage of germinal vesicle break-down (78.08 vs 74.24), metaphase I (89.13 vs 87.18), and metaphase II (77.91 vs 76.38) when evaluated after 8, 14, and 24 h of maturation, respectively, between oocytes from treated and slaughterhouse (untreated) prepubertal ewes. The embryo cleavage (71.1 vs 73.7) and blastocyst rates (22.2 vs 19.8) were similar in the treated and the untreated prepubertal ewes after transfer of in vitro matured oocytes into ligated oviducts of temporary recipients. The in vitro viability rates of vitrified blastocysts (81.2 vs 76.9) and the in vivo survival rates (46.1 vs 50.0) of embryos derived from in vitro matured and in vivo fertilized oocytes showed no difference. The data suggest that gonadotropin treatment increases oocyte production per animal but has no effect on oocyte quality because embryo production and lambing rates of blastocysts derived from in vitro matured oocytes were not markedly different from those derived from untreated prepubertal ewes of the same age

NMR characterization of animals’ follicular fluids

Follicular Fluid (FF) provides a special environment to the oocyte during its maturation in vivo. The FF is derived from the sanguineous plasma and secretions, synthesised in the follicle wall that contain a large variety of metabolites (1). These metabolites are probably involved in the physiology of the oocytes (1). The chemical composition of follicular fluids is important because it is an indicator of the secretory activities and metabolism of follicular cells and thus could be related to the follicular quality. It could also provide a useful indication of the oocyte growth and maturation (2). High Resolution Nuclear Magnetic Resonance (NMR) spectroscopy provides a unique tool for studying metabolites. Initially, NMR spectroscopy was used mainly in biomedicine but it is found now in many physiological applications (3). As the NMR spectroscopy provides opportunities for obtaining qualitative and quantitative data from body fluids, it was hypothesized that this technique could provide information on mammals’ follicular fluid and on intrafollicular changes that occur during follicular growth and ovulation. As some of these changes are probably of crucial importance for oocyte developmental competence, a better knowledge of the mammals’ follicular fluid composition by 1H NMR analysis should help to resolve some of the problems encountered during in vitro procedures in the mammals. The characterization of the chemical composition of mammals follicular fluids, namely sheep, cattle, mare and pork, and the study of the changes observed during follicular growth and maturation using NMR spectroscopy will be presented. FF samples were collected from antral follicle of different dimensions. One-dimensional (1D) 1H experiments (CPMG, DOSY) were obtained for all the FF samples. In addition, several two dimensional (2D) (homo and heteronuclear) experiments (DQF-COSY, TOCSY, JRES, 1H-13C HSQC) were performed to aid in the assignment of the signals and in the identification of the metabolites in FF. A direct evaluation of the lipids, carbohydrates and metabolites were obtained from the combination of the 1D and 2D NMR experiments

M-phase promoting factor (MPF) and mitogen activated protein kinases (MAPK) activities of domestic cat oocytes matured <i>in vitro</i> and <i>in vivo</i>

This work was undertaken in order to examine M-phase promoting factor (MPF) and mitogen-activated protein kinases (MAPK) activities during meiotic progression of cat oocytes cultured in two different media for two different incubation times and preovulatory cat oocytes that reached MII in vivo. Oocytes recovered from ovaries of ovariectomized cats were cultured either in TCM 199 or SOF for 24 h and 40 h. In vivo matured oocytes were recovered by follicular aspiration from ovaries of domestic cats ovariectomized 24 h to 26 h after hormonal treatment. Results showed that the kinetic of MPF and MAPK activity was similar during meiotic progression of cat oocytes matured in TCM 199 and SOF. After 24 h of incubation, MII oocytes had significantly (p &lt; 0.001) higher MPF and MAPK levels than MII oocytes cultured for 40 h in both culture media. MPF and MAPK activity was significantly (p &lt; 0.01) lower in the oocytes matured in vitro than in those matured in vivo. This study provides evidence that the two different maturation media did not determine differences in MPF and MAPK fluctuations and levels during meiotic progression of cat oocytes and that the time of maturation influenced the level of the two kinases. Moreover, it shows that MPF and MPK activity is higher in in vivo matured oocytes than in in vitro matured oocytes, suggesting a possible incomplete cytoplasmic maturation after culture

Sheep embryos derived from FSH/eCG treatment have a lower in vitro viability after vitrification than those derived from FSH treatment

In the non breeding period, the effect of two superovulatory treatments (eCG/FSH in single dose or FSH alone in four decreasing doses) on the production of embryo quality following in vitro viability after vitrification procedures was investigated using forty-four adult Sarda breed ewes. In sheep treated with eCG/FSH, the mean number of corpora lutea was significantly (P &lt; 0.05) higher (11.8±4.0 vs. 8.05±3.8), although the recovery rate was significantly (P &lt; 0.01) lower (74.6 vs. 59.9) than with FSH alone. After vitrification (ethylene glycol and glycerol) was repeated three times, the rates of re-expansion at first and second warming were significantly (P &lt; 0.01) higher in embryos derived from FSH alone than in those with both gonadotrophins (94.9 and 41.9 vs. 72.8 and 18.6) and after the last vitrification the hatched blastocyst rates were 22.5 and 7.6. After differential stain, blastocysts derived from FSH alone showed a mean number of cells significantly higher than blastocysts from eCG/FSH (184.2 vs. 157.7). It was concluded that superovulatory treatment with eCG/FSH may increase the ovarian responses compared with FSH alone, but these embryos showed a reduction in viability rates after repeated vitrification. Pendant la saison non reproductive, on a évalué, chez 44 brebis adultes de race Sarde, l'effet de deux traitements de superovulation (le premier avec les eCG/FSH en une seule administration, le deuxième avec la FSH administrée en quatre doses décroissantes) sur la qualité des embryons produits et sur la viabilité in vitro après vitrification. Dans le groupe traité avec les eCG/FSH, le nombre moyen d'ovulations était plus élevé (11,8±4,0 vs. 8,05±3,8, P &lt; 0,05) tandis que le taux de récupération était plus faible (74,6 vs. 59,9, P &lt; 0,01) par rapport au groupe traité avec la FSH seule. Les embryons ont suivi 3 vitrifications successives (éthylène glycol et glycérol). Les pourcentages de réexpansion de la cavité blastocoelique après les deux premiers cycles de vitrification-décongélation étaient significativement (P &lt; 0,01) supérieurs pour les embryons dérivés du traitement avec la FSH seule par rapport à ceux dérivés du traitement effectué avec les deux gonadotropines (94,9 et 41,9 vs. 72,8 et 18,6). Après la dernière vitrification, les pourcentages d'éclosion étaient respectivement de 22,5 et de 7,6 pour les groupes FSH et eCG/FSH. Après coloration différentielle, les blastocystes dérivés du traitement avec la FSH seule avaient un nombre moyen de cellules supérieur (p &lt; 0,01) par rapport aux blastocystes dérivés du traitement avec eCG/FSH (184,2 vs. 157,7). En conclusion, le traitement superovulatoire avec eCG/FSH augmente la réponse ovarienne par rapport au traitement avec la FSH seule, mais ces embryons montrent une réduction des taux de survie en culture après les processus répétés de vitrification-décongélation

Resveratrol supplementation during in vitro maturation improves embryo development of prepubertal goat oocytes selected by brilliant cresyl blue staining

This study aimed to investigate the effect of resveratrol supplementation in maturation medium on the developmental ability and bioenergetic\oxidative status of prepubertal goat oocytes selected by brilliant cresyl blue (BCB). Oocytes collected from slaughterhouse-derived ovaries were selected by 13 µM BCB staining and classified as grown BCB+ and growing BCB- oocytes. All oocytes were matured in vitro in our conventional maturation medium and supplemented with 1 µM (BCB+R and BCB-R) and without (Control groups: BCB+C and BCB-C) resveratrol. After 24 h, IVM-oocytes were fertilized with fresh semen and presumptive zygotes were in vitro cultured for 8 days. Oocytes were assessed for blastocyst development and quality, mitochondrial activity and distribution, and levels of GSH, ROS, and ATP. BCB+R (28.3%) oocytes matured with resveratrol presented significantly higher blastocyst development than BCB+C (13.0%) and BCB- groups (BCB-R: 8.3% and BCB-C: 4.7%). Resveratrol improved blastocyst development of BCB-R oocytes at the same rate as BCB+C oocytes. No differences were observed in blastocyst quality among groups. GSH levels were significantly higher in resveratrol groups (BCB+R: 36554.6; BCB-R: 34946.7 pixels/oocyte) than in control groups (BCB+C: 27624.0; BCB-C: 27655.4 pixels/oocyte). No differences were found in mitochondrial activity, ROS level, and ATP content among the groups. Resveratrol-treated oocytes had a higher proportion of clustered active mitochondria in both BCB groups (BCB+R: 73.07%; BCB-R: 79.16%) than control groups (BCB+C: 19.35%; BCB-C: 40%). In conclusion, resveratrol increased blastocyst production from oocytes of prepubertal goats, particularly in better quality oocytes (BCB+)

Two culture systems showing a biphasic effect on ovine embryo development from the 1-2 cell stage to hatched blastocysts

This study compared the effect of using either CZB or TCM 199 media on both the development of 1-2 cell ovine embryos from superovulated ewes to the blastocyst stage (Experiment 1), and the hatching process of ovine blastocysts developed in vitro (Experiment 2). For the first 5 d, the CZB medium showed higher rates of embryo development than the TCM 199 medium (p &lt; 0.001). The embryos reaching the &gt; 16 cell stage were 79 vs 52% and 74 vs 20% with or without an oviductal monolayer, respectively, and those reaching the blastocyst stage were 71 vs 46% and 46 vs 13% with or without cells. The CZB medium was less able to support the hatching process of the blastocysts obtained in the first experiment than was the TCM-199 medium + 10% FCS (fetal calf serum) with cells (31 vs 92%; p &lt; 0.001) or without cells (13 vs 66%; p &lt; 0.001). No blastocysts completely escaped from the zona pellucida (ZP) in the CZB medium compared with 80 and 61 % in the TCM 199 medium with or without cells, respectively. In Experiment 3, 47% of the blastocysts migrated through the artificial opening of the ZP and hatched completely. After 24 h of culture in the CZB medium, however, they showed blastocoelic cavity breakdown. During the preliminary cleavages, the ovine embryos developed better in CZB medium than in TCM 199, but the latter was more efficient in promoting the hatching process of the blastocysts. Les effets d’un milieu de culture, CZB, et d’un milieu de culture, TCM 199 + 10% de sérum de veau foetal, ont été observés sur le développement in vitro d’embryons d’ovins du stade 1-2 cellules au stade blastocyste (expérience 1) et dans le processus d’éclosion des blastocystes produits lors de l’expérience précédente (expérience 2). Le milieu CZB exerce un effet positif sur le développement embryonnaire par rapport au milieu TCM 199 après culture jusqu au stade &gt; 16 cellules (79 vs 52 % et 74 vs 20%) ou jusqu’au stade blastocyste (71 vs 46% et 46 vs 13%) en présence de cellules et en l’absence de cellules tubaires respectivement. Le processus d’éclosion est plus faible dans le milieu CZB que dans le milieu TCM 199 soit en présence (31 vs 92%) soit en l’absence (13 vs 66%) de cellules tubaires respectivement. Dans le CZB (expérience 3), 47% des blastocystes éclosent par une fente artificielle dans la zone pellucide, mais, après 24 h de culture, la cavité blastocoelique se dégonfle. Ces résultats montrent que le milieu CZB est plus indiqué pour le développement précoce d’embryons ovins alors que le milieu TCM 199 est plus efficace au moment de la phase d’éclosion

Influence of co-culture with oviductal epithelial cells on in vitro maturation of canine oocytes

The process of oocyte maturation in the canine species is unique among mammals: oocytes are immature at ovulation and the resumption and progression of meiotic maturation occur in the oviduct. This study was performed to investigate (i) the effect of co-culture with infundibulum and ampullar oviductal epithelial cells on the in vitro maturation of canine oocytes and (ii) the culture time necessary to reach full meiotic maturation. For this purpose the oocytes, collected from the ovaries of bitches undergoing ovariectomies, were divided into three groups and cultured for 48 and 72 h with the following systems: (A) TCM 199 + 10% oestrus bitch serum + FSH (0.1 IU•mL–1), LH (0.1 IU•mL–1)+ progesterone (1 μg•mL–1) + oestradiol (1 μg•mL–1) + cysteamine (100 μM); (B) medium A plus infundibulum cells; (C) medium A plus ampullar cells. Infundibulum and ampullar cells were recovered from the oviducts of bitches at the oestrus stage of their cycle. The results showed that after 48 h of incubation, a significantly higher meiotic resumption (P &lt; 0.01) was observed in the oocytes cultured with infundibulum (59%) and ampullar cells (60.0%), than in the control group (40.0%). There was also a significantly (P &lt; 0.01) higher meiotic progression to the MII in systems B and C (15.6% and 16.7%) than in system A (4.0%). After 72 h of culture, the percentages of meiotic resumption and progression were unchanged. These results showed that both the infundibulum and the ampullar oviductal epithelial cells positively influence the meiotic resumption and progression of canine oocytes and that 48 h are sufficient for the completion of nuclear maturation