bluuebunny/crossref_metadata_2025 huggingface dataset:
106 ADAPTIVE β-CELL EXPANSION IN PREGNANT MICE WITHOUT FETUSES
Authors: Zhang S. , Zhang X. M. , Li Z. Y.
Published: December 2013

Diabetes, an increasingly prevalent metabolic disorder, which is estimated to affect over 300 million people by 2025 (Zimmet et al. 2001 Nature), commonly results from β-cell function failure. In normal physiological conditions, β-cell turnover occurs slowly throughout the lifetime of the adult mammal. During pregnancy, β cells could increase their replication rate through reducing menin expression and then cause islets hyperplasia to match the physiological demands (Karnik et al. 2007 Science). However, whether the fetuses have an influence on the β-cell replication and islets hyperplasia during pregnancy is still unknown. The objective of the present study was to test whether pregnancy without fetuses could also decrease the expression of menin, and then cause an increase in the β-cell replication rate and islets hyperplasia. First, we generated pregnant mice with tetraploid blastocysts (PT mice), which can implant and generate placentas similar to the normal diploid blastocysts, but cannot develop into fetuses. Pancreases from at least 3 mice per group were embedded in optimum cutting temperature compound (OCT) and sectioned at 8-μm intervals. The sections were stained with hematoxylin and eosin (HE), and then the morphological structures of islets were observed under a microscope. The results showed that the islets mass of PT mice had obvious hyperplasia compared with wild-type controls (WT). Second, we isolated the islets of PT mice, and analysed the Men1, p18, and p27 gene expression in PT mice islets using RT-PCR. We found that the expression of Men1, p27, and p18 in PT mice islets was significantly lower compared with WT controls (P < 0.05). Finally, insulin immunofluorescence was performed to evaluate the insulin expression level of β cells in the islets both from PT mice and the WT group. The evaluation of total fluorescence intensity in islets was performed. The average value from the control group islets was set to 1 and used for comparison to the fluorescence intensity of PT mice islets. The results showed that there was no significant difference between PT mice and WT groups at the insulin level of β cells. Taken together, these results demonstrate that under the conditions of pregnancy without fetuses, maternal pancreatic islets can also cause islets mass hyperplasia through reducing menin expression, but not increase the insulin level per β cell to match the dynamic physiological demands. Therefore, it's possible to treat type-2 diabetes by imitating the pregnant physiological condition without fetuses.
This work was supported by grants from the National Natural Science Foundation (No. 31271591) and the National Basic Research Program (No. 2009CB941001 and No. 2011CBA01003) in China.
127 TREATMENTS WITH DIVERSE ENDOCRINE-DISRUPTING CHEMICALS RESULTED IN THE INHIBITION OF OVARIAN TUMOR PROGRESSION VIA INTERRUPTION OF TRANSFORMING GROWTH FACTOR-β IN IN VITRO AND XENOGRAFTED MOUSE MODELS
Authors: Lee H.-R. , Go R.-E. , Choi K.-C.
Published: December 2013

Activated oestrogen receptor (ER) signaling pathway by 17β-estadiol (E2) appeared to suppress transforming growth factor β (TGF-β) signaling pathway by cross-talk with TGF-β components in ER-positive cancer cells. In this study, we further examined the inhibitory effects of alkylphenols, including 4-nonylphenol (NP), 4-otylphenol (OP), bisphenol A (BPA), and benzophenon-1 (BP-1), in TGF-β signaling pathway. The transcriptional and translational levels of TGF-β-related genes were examined by reverse-transcription PCR (RT-PCR), Western blotting analysis in xenografted mouse models of ovarian cancer BG-1 cells. The NP, OP, and BPA induced the expression of snoN, a TGF-β pathway inhibitor. Treatment with NP, BPA, and BP-1 resulted in decreased phosphorylation of Smad3, a downstream target of TGF-β. With these 2 effects, NP and BPA stimulated the proliferation of BG-1 cells via inhibition of the TGF-β signaling pathway. In a xenograft mouse model, transplanted BG-1 ovarian cancer cells showed significantly decreased phosphorylation of Smad3 and increased expression of snoN in the ovarian tumour masses following treatment with E2, NP, or BPA. In parallel with an in vitro model, the expressions of TGF-β signaling pathway were similarly regulated by NP or BPA in a xenograft mouse model, revealing consistent results. Taken together, these results support that NP and BPA may cause the disruption of the TGF-β signaling pathway and increase the risk of oestrogen-dependent cancers such as ovarian cancer.
This work was supported by a grant from the Next-Generation BioGreen 21 Program (No. PJ009599), Rural Development Administration, Republic of Korea.
128 EXPRESSIONS OF MOUSE TIGHT JUNCTION MOLECULES IN PLACENTA – CLAUDINS AND OTHER PARACELLULAR TRANSPORT MOLECULES
Authors: Ahn C. , Lee J. S. , Jeung E. B.
Published: December 2013

Tight junctions (TJ) are composed of a branching network of sealing strands. Tight junctions regulate paracellular conductance and ionic selectivity. The TJ components include the peripheral protein ZO-1, junctional adhesion molecules (JAM), and integral proteins, such as occludin and claudin. Claudins, a family of proteins, are the most important components in TJ. They establish paracellular transport barriers, which control transportation of molecules within intercellular space. The current study focused on expression of claudin, suggesting claudin as a major working molecule in the paracellular transport system. In order to study the mechanisms and roles of the claudin family, the expression levels of claudin family in various organs should be determined. In this study, we examined expression of the mouse placental claudin family. Pregnant C57/BL6 mice (n = 5) were used in this study, and compared with β-actin, expression of TJ proteins, including Claudin-1 to Claudin-24, JAM-a, Zo-1, and occludin, tricellulin, and MarvelD3 was examined. In the transcription levels, Claudin-1 and -4 proteins were predominantly expressed. Claudin-1 and -4 have been known as a responsive gene for a direct decrease in paracellular conductance by selective reduction of the permeability of Na+ ions. On the other hand, Claudin-2, Claudin-3, Claudin-5, Cludin-11, and Claudin-12 showed ~33% expression compared with Claudin-1. Claudin-6 and Claudin-7 showed ~20% relative expression compared to Claudin 1. Claudin-10a and Claudin-16 were not detectable by real-time RT-PCR under our experimental conditions. Other claudin proteins showed low expression. Because the transcriptional levels of TJ genes were expressed variously, protein levels and their localization in the placenta will be further evaluated by immunostaining and Western blot assay. This study will provide data on expression of TJ genes and their localization in the mouse placenta, which may contribute to assuming the roles of these TJ genes regarding maternal-fetal ion transportation in the placenta.
13 MOTILITY CHARACTERISTICS OF SPERMATOZOA FROM BULLS GRAZING TALL FESCUE PASTURES
Authors: Harris J. P. , Edwards J. L. , Rispoli L. A. , Rorhbach N. R. , Prado T. M. , Saxton A. M. , Schrick F. N.
Published: December 2013

Fertilisation is less than expected with spermatozoa from bulls consuming toxic endophyte-infected (E+) tall fescue. The objective of this study was to evaluate motility characteristics of spermatozoa from bulls grazing tall fescue pastures using computer-assisted sperm analysis (CASA). Semen was collected from six Angus bulls (average age = 15.1 ± 0.04 months) during a three-month grazing study. Bulls grazed Kentucky 31 tall fescue (Festuca arundinacea Schreb.) infected with Neotyphodium coenophialum, an ergot alkaloid-producing endophyte (n = 3), or Jesup tall fescue with Max-Q™ (NTE), a non-ergot alkaloid producing endophyte (n = 3), and grouped by body weight and scrotal circumference to graze pastures from April 18 to June 26. Semen was collected once per week between 0600–0800 h beginning in mid-May and ending the last week of June. Gross motility and morphology was evaluated before extending with Bioxcell® animal protein-free formula (IMV, Aigle, France) and antibiotics (CSS 100, 2% of total volume). Extended semen was then evaluated using CASA to determine final dilution and packaged into straws (20 million sperm/straw), where equilibration occurred over 3 h in a cold room at 4°C. Straws were frozen for 7 min in static vapor of liquid nitrogen and plunged into goblets filled with liquid nitrogen. Semen was thawed and assessed using CASA at 0 and 3 h post-thaw. Data were analysed as a randomised block design with the fixed effects of treatment, blocking on semen collection date, utilising the mixed models procedure of SAS 9.2 (SAS Institute Inc., Cary, NC, USA). Data were tested for normality (Shapiro-Wilk W ≥ 0.90), and treatment differences were determined using F-protected least significant differences. Path velocity (P = 0.001) and progressive velocity (P = 0.003) were lower in spermatozoa from bulls grazing E+ during the last 2 weeks of collection in June independent of time of assessment post-thaw. Sperm head area decreased in size in spermatozoa from E+ grazing bulls at 3 h post-thaw (P = 0.04) compared with NTE grazing bulls. Percent of rapid (progressive % with path velocity >50 μm s–1) and medium (progressive % with path velocity <50 μm s–1 but > 30μm s–1) velocity spermatozoa was decreased for E+ grazing bulls compared to NTE grazing bulls (P < 0.0001 and P = 0.004, respectively) and was accompanied by an increase in static (immobile) spermatozoa from E+ bulls (P < 0.0001). These findings indicate that spermatozoa movement and velocity are impaired in bulls grazing E+ tall fescue pastures compared to bulls grazing NTE tall fescue pastures after the freeze and thaw process, which may explain decreased fertilisation and cleavage rates of oocytes co-incubated with these spermatozoa.
132 REFERENCE GENE SCREENING FOR ANALYZING GENE EXPRESSION ACROSS FEMALE GOAT TISSUE
Authors: Zhang X.-D. , Zhang Y. , Liu X. , Li Y.-S. , Ding J.-P. , Zhang X.-R. , Zhang Y.-H.
Published: December 2013

Quantitative RT-PCR (RT-qPCR) is an important method for investigating changes in mRNA expression levels in cells and tissues. Selection of the proper reference genes is very important when calibrating the results of RT-qPCR. Studies on the selection of reference genes in goat tissues are limited, despite the economic importance of their meat and dairy products. We applied absolute quantification using the standard curve method to the detection of the expression levels of 8 reference gene candidates (18S, TBP, YWHAZ, HMBS, ACTB, HPRT1, GAPDH, and EEF1A2) in 10 different tissue types (heart, liver, spleen, lung, kidney, stomach, uterus, ovary, small intestine, and muscle) sourced from a 5-month-old female Boer goat. All the experiments were performed using 3 biological replicates and technical triplicates of each cDNA sample. The optimal reference gene combination was selected according to the results determined by geNorm, NormFinder, and Bestkeeper software packages. The analyses showed that tissue is an important variability factor in gene expression stability. When all tissues were considered, 18S, TBP, and HMBS with the smallest paired variation coefficient is the optimal reference combination for calibrating RT-qPCR analysis of gene expression from goat tissues. The stability of each gene was evaluated, taking into account all of the data. The stability values (M) for these genes were 0.643/0.634/0.799, 0.156/0.467/0.584, and 0.396/0.445/0.566 by geNorm, NormFinder, and Bestkeeper, respectively. Dividing the dataset by different tissues, ACTB was the most stable in stomach, small intestine, and ovary, 18S in heart and spleen, HMBS in uterus and lung, TBP in liver, HPRT1 in kidney, and GAPDH in muscle. Overall, this study provided valuable information about the female goat reference genes that can be used in order to perform a proper normalisation when relative quantification by RT-qPCR studies is undertaken.
This work was supported by National ‘863’ Program (2011AA100307-4), the Technology Innovation Project – Special Program and the Science and Technology Program of Anhui Province (11Z0101095 and 11010302108).
133 EFFECT OF PROGESTERONE SUPPLEMENTATION OF MATURATION MEDIUM ON THE DEVELOPMENT OF IN VITRO-MATURED-IN VITRO-FERTILIZED-IN VITRO-CULTURED BOVINE EMBRYOS
Authors: Syoji K. , Imai K. , Koyama H. , Dochi O.
Published: December 2013

The objective of this study was to investigate whether progesterone (P4) supplementation to in vitro maturation (IVM) medium could affect the competence of bovine oocyte to develop into blastocysts in vitro. Cumulus–oocyte complexes (COC) were collected by aspiration of ovarian follicles (2 to 6 mm in diameter) obtained from a local abattoir. The COC were matured for 20 h in TCM-199 supplemented with 5% calf serum and 0.02 AU mL–1 FSH at 38.5° in an atmosphere of 5% CO2 in air. After 18 h of gamete co-culture (5 × 106 sperms mL–1), presumptive zygotes were cultured in CRlaa containing 5% calf serum at 38.5°C in an atmosphere of 5% CO2, 5% O2, and 90% N2 for 9 days (fertilization = Day 0). Progesterone was added to the IVM medium 10 h after the start of the culture (1 μg group = 1 μg mL–1 of P4; 5 μg group = 5 μg mL–1 of P4; control group = no P4). The maturation (MII) rates were investigated after 20 h of starting the IVM culture. After maturation, the COC were denuded mechanically, and a part of the oocytes were mounted on slides, fixed with aceto-alcohol (1 : 3) solution for 48 h, stained with aceto-orcein, and observed under a phase-contrast microscope to determine their nuclear status (1 μg group: n = 32; 5 μg group: n = 28; control group: n = 31). The remaining COC were used for IVF. The cleavage rates were investigated on day 2, and the blastocyst formation rates were investigated on Days 7 to 9, respectively (1 μg group: n = 264; 5 μg group: n = 274; control group: n = 277). The blastocysts from Day 7 were used for differential staining of the inner cell mass (ICM) and trophectoderm cells (TE). The total cell numbers, ICM, and TE in the blastocysts were counted (1 μg group: n = 28; 5 μg group: n = 24; control group: n = 24). The rates of MII, cleavage, and blastocyst formation were expressed and analysed by the chi-squared test. Each set of cell numbers (mean ± standard error) was analysed by the unpaired t-test. The MII rate in the control group (76.7%) was significantly lower (P < 0.05) than that in the 1 μg group (93.8%). The cleavage rate in the 1 μg group (85.6%) was significantly higher (P < 0.05) than those in the control group (74.7%) and 5 μg group (77.4%). Further, the blastocyst formation rate in the 1 μg group (47.7%) and 5 μg group (43.4%) were significantly higher (P < 0.05) than that in the control group (35.0%). The ICM numbers (mean ± s.e.) were 39.5 ± 13.8 to 36.2 ± 8.9, the TE numbers were 74.4 ± 22.4 to 66.2 ± 12.9, the total cell numbers of blastocysts were 110.6 ± 28.2 to 103.0 ± 13.8. There was no significant difference in cell numbers among the groups. These results indicate that the cleavage and blastocyst formation rates can be improved by the addition of 1 μg mL–1 of P4 to the maturation medium.
136 BLASTOCOELE COLLAPSE IMPROVES POST-THAW SURVIVAL OF SLOW FROZEN AND VITRIFIED IN VITRO-PRODUCED BOVINE EMBRYOS
Authors: Barfield J. P. , Seidel G. E.
Published: December 2013

Slow-freeze cryopreservation of in vitro-produced bovine embryos often results in poor post-thaw embryo viability. Results with vitrification tend to be better but do not always produce consistent results for a variety of reasons. Experiments with human and equine embryos have demonstrated improved post-thaw survival when blastocoele fluid is removed before vitrification. We hypothesised that removing blastocoele fluid before vitrification or slow-freeze cryopreservation would improve post-thaw survival of in vitro-produced bovine embryos. Three replicates of embryos were generated from abattoir-derived ovaries using standard techniques. Seven days post-fertilization, embryos were evaluated for quality, and grade 1 or 2 embryos were allocated to 1 of 4 treatments: slow-freeze control (n = 103); slow-freeze collapsed (n = 106); vitrified control (n = 117); vitrified collapsed (n = 99). Blastocoele fluid was removed by aspiration with a pipette advanced to the centre of the blastocoele while the embryos were stabilised with a holding pipette. After collapse, embryos were immediately slow frozen in commercial medium [1.5 M ethylene glycol (EG) + 0.1 M sucrose, Bioniche] in 0.25-mL straws or vitrified in 2 steps: 3 min in 1.5 M EG, 30 s in 7 M EG + 0.6 M galactose + 18% Ficoll in open-pulled straws. After thawing or warming, embryos were cultured in chemically defined medium-2 + 5% FCS in 5% CO2, 5% O2, 90% N2 at 38.5°C. Embryos were evaluated for survival based on re-expansion of the blastocoele after 24 h in culture. Data were analysed by GLIMMIX (SAS Institute Inc., Cary, NC, USA). There were significant replicate effects but there were no significant differences in survival between embryos that were vitrified or slow frozen. Approximately twice as many collapsed embryos survived compared to intact control embryos regardless of whether the embryos were vitrified or slow frozen (collapsed: 50.5 ± 4.1%, control: 26.3 ± 3.5%; P < 0.001). Advanced blastocysts (fully expanded and hatched blastocysts) survived better than early blastocysts (pre-expansion blastocysts and expanding blastocysts, 45.9% ± 3.9 v. 30.0% ± 4.4, respectively; P < 0.01). The only significant interaction (P < 0.05) was that vitrification was superior to freezing for early blastocysts (39.5 ± 5.9% v. 22.1 ± 5.0% survival) but not advanced blastocysts (44.4 ± 5.3% v. 47.4 ± 5.8% survival). Removal of blastocoele fluid before cryopreservation of in vitro-produced bovine embryos may be a useful technique for improving post-thaw survival regardless of cryopreservation method or blastocyst stage.
140 THE EFFECTS OF INTERVALS OF MECHANICAL VIBRATION DURING IN VITRO CULTURE ON THE DEVELOPMENT OF BOVINE EMBRYO DERIVED FROM LOW-QUALITY OOCYTES
Authors: Takehisa M. , Kondo S. , Imai K. , Dochi O. , Koyama H.
Published: December 2013

Mechanical vibration enhances the cytoplyasmic maturation of in vitro-matured (IVM) pig oocytes (Mizobe et al. 2010 J. Reprod. Dev. 56, 285–290), as well as the development of in vitro-cultured (IVC) bovine embryos (Fujita et al. 2010 Rakuno Gakuen University Graduation thesis,1–36). In this study, the effects of intervals of mechanical vibration during in vitro culture, after IVF, on the development of embryos derived from low-quality oocytes were examined. Cumulus-oocyte complexes (COC) were collected by aspiration of ovarian follicles (diameter = 2 to 6 mm) obtained from a local abattoir. In this experiment, only grade 3 oocytes (i.e. those with one layer or partially remaining cumulus cells and normal cytoplasm) were used. Groups of 20 COC were matured in 100-μL droplets of in vitro TCM-199 supplemented with 5% calf serum and 0.02 AU mL–1 of FSH at 38.5°C under an atmosphere of 5% CO2 in air for 20 h. Matured COC were inseminated with 5 × 106 sperms mL–1 for 18 h. After 18 h of gamete co-culture, the presumptive zygotes were cultured in CR1aa medium supplemented with 5% calf serum at 38.5°C under an atmosphere of 5% O2, 5% CO2, and 90% N2 for 9 days (fertilization = Day 0). Presumptive zygotes were cultured in vitro without mechanical vibration (control; n = 467) and with mechanical vibration for 5 s at 5 min (n = 180), 10 min (n = 180), 15 min (n = 180), and 60 min (n = 200) for 9 days. Embryo development was evaluated for cleavage and blastocyst rates, on Days 3 and 7 to 9 after IVF, respectively. The cleavage and blastocyst formation rates were analysed by the chi-squared test. Vibration at 15-min intervals increased (P < 0.05) cleavage rate compared to 5 min, 60 min, and control (control: 66.2 ± 22.1%; 5 min: 49.4 ± 10.2%; 10 min: 70.0 ± 7.7%; 15 min: 86.2 ± 6.6%; and 60 min: 64.0 ± 8.5%).The highest (P < 0.05) blastocyst rate among the experimental groups was found with 15-min intervals for vibration (control: 21.6 ± 9.2%; 5 min: 15.0 ± 5.3%; 10 min: 22.8 ± 1.8%; 60 min: 21.5 ± 5.0%). These results indicated that the cleavage and blastocyst formation rates of IVM-IVF-IVC bovine embryos derived from low-quality oocytes can be improved by physical stimulus during IVC. In addition, it was shown that 15-min intervals of mechanical vibration elicited the highest benefit for the development of embryos.
145 EFFECT OF RELAXIN ON FERTILIZING ABILITY OF BUFFALO SPERM
Authors: Elkhawagah A. R. , Longobardi V. , Sosa G. A. , Albero G. , Salzano A. , Zullo G. , Bifulco G. , Gasparrini B.
Published: December 2013

The aim of this work was to evaluate the effect of relaxin, known to improve fertility parameters of frozen-thawed sperm in other species (Miah et al. 2006 J. Reprod. Dev. 52, 773–779; Miah et al. 2007 Anim. Sci. J. 78, 495–502), on buffalo sperm motility, capacitation, and fertilizing capability. Frozen-thawed sperm from 2 bulls (4 replicates each) were separated by Percoll, diluted to a 20 × 106 mL–1 concentration and incubated in TALP medium in the absence of capacitating agents (negative control), in the presence of 10 μg mL–1 of heparin (positive control) and 100 ng mL–1 of relaxin for 2 h. Following incubation, sperm were exposed for 15 min to 60 mg mL–1 of lysophosphatidylcholine, a fusogenic agent known to induce the acrosome reaction only on capacitated sperm. To evaluate acrosome-reacted (AR) live sperm, cells were fixed and stained with Trypan blue-Giemsa (Kovacs and Foote 1992 Biotech. Histochem. 67, 119–124) and evaluated (800 sperm counted/group). Sperm motility was examined by a phase contrast microscope, whereas the fertilizing capability was evaluated by heterologous IVF. Abattoir-derived bovine oocytes (n = 258, 86 per group) were in vitro matured and fertilized according to standard procedures (Rubessa et al. 2011 Theriogenology 76, 1347–1355) with buffalo sperm in the absence of capacitating agents and in the presence of 10 μg mL–1 of heparin and 100 ng mL–1 of relaxin. Twenty hours after IVF, presumptive zygotes were denuded and cultured in SOF for 24 h, when cleavage rate was evaluated and confirmed by fixation with absolute ethanol overnight and staining with 2.5 μg mL–1 of Hoechst 33342 after zona removal by pronase (2 mg mL–1) digestion. The differences in the percentages of AR sperm and cleavage among groups were analysed by a chi square test and those in sperm motility by Student's t-test. Acrosomal loss was observed in 10.8% of the sperm after thawing, which may indicate freezing-induced capacitation, and, hence, this value was detracted from the percentages of AR recorded following incubation. After 2 h of incubation, 100 ng mL–1 of relaxin significantly (P < 0.05) increased the percentages of live AR sperm (P < 0.05) compared with the negative control (31.3 ± 2.2 and 25.8 ± 2.8, respectively), with intermediate results in the positive control (27.0 ± 2.2). Motility was significantly improved (P < 0.05) when sperm were exposed to 100 ng mL–1 of relaxin compared with both the negative and positive control (73.7 ± 2.4, 60.0 ± 4.1, and 60.0 ± 7.1, respectively). A significant (P < 0.05) improvement of cleavage rate was recorded both in the positive control (71.5 ± 4.8) and in the group treated with 100 ng mL–1 of relaxin (70.7 ± 0.5) compared with negative control (52.1 ± 1.5). In conclusion, these preliminary results indicate that relaxin at the concentration of 100 ng mL–1 improves sperm motility, capacitation, and the IVF capability of buffalo sperm.
150 SERUM TESTOSTERONE CONCENTRATIONS IN BULLS SUPPLEMENTED WITH RUMEN-PROTECTED FAT, ANTIOXIDANTS, OR BOTH
Authors: Guardieiro M. M. , Silva F. L. M. , Monteiro P. L. J. , Nascimento A. B. , Gentil R. S. , Arruda W. , Chinelato G. M. , Lemes A. , Mourão G. B. , Oba E. , Sartori R.
Published: December 2013

Testosterone metabolism occurs primarily in the liver, and circulating concentrations can be influenced by the amount and type of diet provided. Furthermore, there are reports of the influence of circadian rhythms on secretion of testosterone in ruminants. Based on evidence that supplementation with rumen-protected fat may increase circulating concentrations of steroid hormones (Guardieiro et al. 2010 Pesq. Agrop. Bras. 45, 408–414), this study aimed to evaluate the effect of the addition of rumen-protected fat, antioxidants, or both to the diet on serum testosterone concentration in bulls, and to assess whether there is variation in hormone concentrations at different times of the day after feeding. Forty-eight Nelore bulls were confined and assigned to four treatment groups according to the addition of rumen-protected fat, antioxidants, or both to the standard diet (sugarcane bagasse, citrus pulp, corn gluten meal, urea, and mineral salt): F) rumen-protected polyunsaturated fatty acids [PUFA; rich in linoleic, Megalac E®, QGN-Arm & Hammer, Rio de Janeiro, Brazil; 1.5% on dry matter (DM); n = 12]; A) antioxidant (a source of vitamin C and selenium, EconomasE®, Alltech Biotechnology, Buenos Aires, Argentina; 3 g/head/d; n = 12); FA) Megalac E® and EconomasE® (n = 12), or C) nothing (Control group; n = 12). After 75 days of offering diets, jugular blood samples were collected just before IV injections that were performed three times a day (7:00, 13:00, and 19:00 h) with saline (Control group, n = 24) or gonadotropin-releasing hormone (GnRH; 50 μg Gonadorelin, Fertagyl, MSD Saúde Animal, São Paulo, Brazil; GnRH group, n = 48) and 2 h afterward. Bulls were fed 1 h after the first IV GnRH/saline and the diets remained in the bunk for 17 h. Serum testosterone concentrations were measured by radioimmunoassay. Data were analysed by repeated-measures of GLIMMIX of SAS (SAS Institute Inc., Cary, NC, USA). As expected, the GnRH injections increased concentrations of testosterone after 2 h compared to saline (5.4 ± 0.16 v. 3.2 ± 0.16 ng mL–1; P < 0.001). However, after the last injection of GnRH there were lower (P < 0.001) concentrations of testosterone (2.0 ± 0.57) compared to other times. This fact may be explained by the probable association between the greater clearance of testosterone after feeding and the consumption of stock of pituitary LH by GnRH administration. However, there was no effect of diets on circulating testosterone concentration. We may suggest that males can more efficiently control steroid hormone concentrations than females by feedback mechanisms.
Financial support was provided by CNPq, FAPESP, Arm & Hammer, Alltech, and EMBRAPA of Brazil.
156 EFFECTS OF MORPHOLOGY TYPE OF POLAR BODY ON PORCINE OOCYTE QUALITY AND DEVELOPMENTAL POTENTIAL AFTER IN VITRO FERTILIZATION
Authors: Cai L. , Kim E. , Hwang S. U. , Yoon J. D. , Jeon Y. , Lee E. , Hyun S. H.
Published: December 2013

Evaluation of morphology of first polar body (1st PB) could be a method for the oocyte's quality and developmental competence. The developmental potential of oocyte with fragmented PB after in vitro maturation (IVM) is a controversial issue. The aim of this study is to investigate the effects of PB morphology type on oocyte quality and developmental competence after IVF. Porcine ovaries were obtained from prepubertal gilts at a local slaughterhouse and transported to the laboratory within 2 h in physiological saline supplemented with 100 IU mL–1 penicillin G and 100 mg mL–1 streptomycin sulfate. The cumulus–oocyte complexes (COC) were aspirated using an 18-gauge needle attached to a 10-mL disposable syringe from superficial follicles 3 to 6 mm in diameter followed by IVM. After IVM, oocytes were classified into 3 types as follows, oocytes with normal PB (A type), oocytes with a little of fragmented PB (B type), and oocytes with separated 2 PBs (C type), respectively. As classification of PB types, we analysed the distribution ratio of each PB type after IVM, and then performed IVF for analysis of fertilization rate and developmental potential. The ratio of oocyte with A type (73%) was significantly (P < 0.05) higher than that of B type (24.5%) or C type (2.5%) after IVM. Only mature oocytes were selected from A and B type and were subjected to IVF because of a small number of oocytes with C type. In the IVF experiment, the efficiency of monospermy and fertilization were significantly higher in oocytes of A type (46.7%) than those of type B (20.0%). The cleavage rate of oocytes with A type (63.9%) was significantly (P < 0.05) higher than the oocytes with B type (43.8%). Embryonic developmental competence to the blastocyst stage after IVF was significantly (P < 0.05) higher in the A-type oocytes (26.3%) than in the B-type oocytes (16.9%). The levels of glutathione and reactive oxygen species were not affected by the morphological classification of the PB. In summary, these results suggest that polar body morphology could be a marker of oocyte quality after IVM. We are currently studying gene expression of each oocytes and blastocysts.
This work was supported, in part, by a grant from the Next-Generation BioGreen 21 Program (No. PJ00956901), Rural Development Administration, and the National Research Foundation of Korea Grant funded by the Korean Government (NRF-2012R1A1A4A01004885, NRF-2013R1A2A2A04008751), Republic of Korea.
159 EFFECT OF 3-ISOBUTYL-1-METHYLXANTHINE (IBMX) ON THE GERMINAL VESICLE STAGE OF PORCINE OOCYTES DURING OOCYTE COLLECTION IN VITRO
Authors: Appeltant R. , Beek J. , Maes D. , Van Soom A.
Published: December 2013

When using modern maturation conditions for in vitro maturation, pig oocytes yield ~20% blastocysts only. One problem is that cumulus cells, which are normally connected with the immature oocyte by cellular projections penetrating through the zona pellucida and with the oolemma via gap junctions, are prematurely losing these connections after the cumulus–oocyte complex is removed from the follicle. The oocyte possesses a type 3 phosphodiesterase, which degrades 3′,5′-cyclic adenosine monophosphate (cAMP), and this activity is inhibited by supply of 3′,5′-cyclic guanosine monophosphate (cGMP) to the oocyte via the cumulus cells. Consequently, cAMP levels, which are typically high during early stages of oocyte maturation in vivo, decrease, leading to spontaneous nuclear maturation and oocytes of low developmental competence. Therefore, the maintenance of these cumulus-oocyte connections is important to keep cAMP high and the oocyte under meiotic arrest. One way to prevent this drop in cAMP is using N6, 2′-o-dibutyryladenosine 3′,5′-cyclic monophosphate sodium (dbcAMP) that causes an arrest at germinal vesicle (GV) stage II (Funahashi et al. 1997 Biol. Reprod. 57, 49–53). Another option is collecting the oocytes in a medium containing the phoshodiesterase inhibitor, IBMX. The present study investigated the influence of IBMX on the progression of the GV of the oocyte after collection, just before the start of the maturation procedure. The GV stage was defined according to Sun et al. (2004 Mol. Reprod. Dev. 69, 228–234). In parallel with the findings on dbcAMP, we hypothesised an arrest at GV II by the presence of IBMX during collection. One group of oocytes were collected in HEPES-buffered TALP without IBMX (n = 375) and another group in the same medium containing 0.5 mM IBMX (n = 586). An average incubation time of 140 min was applied in both groups, and 3 replicates were performed. The proportions of oocytes before or at GV II and beyond GV II were compared in both groups using logistic regression analysis. The proportion of oocytes was included as dependent variable and group (IBMX addition or not) as independent variable. Replicate was also included in the model. The proportion of oocytes before or at GV II was not statistically significant between the group without and the group with IBMX (59.2 v. 58.7% respectively; P > 0.05). In conclusion, the use of IBMX during oocyte collection did not influence the state of the germinal vesicle of the oocyte during collection, indicating that IBMX did not cause a meiotic arrest in the oocytes during collecting in vitro.
160 EFFECT OF cAMP MODULATORS ON IN VITRO MATURATION OF BOVINE OOCYTES
Authors: Farmer S. E. , Adams T. L. , Sarmiento-Guzmán J. A. , Bailey C. L. , Bondioli K. R.
Published: December 2013

The efficiency of in vitro production (IVP) has remained low due to an inadequate in vitro maturation (IVM) system. Thus far, the most promising methods of improving IVM utilise cAMP modulators to slow the maturation process by keeping cAMP high. This experiment compares standard IVM to an extended IVM as previously described by Albuz (2010 Hum. Reprod. 25, 2999–3011). The extended IVM consists of a 2-h pre-IVM phase with FSK (an adenylate cyclase activator) and 3-isobutyl-1-methylxanthine [IBMX, a nonspecific phosphodiesterase (PDE) inhibitor], followed by a 31-h IVM phase with cilostamide (a PDE3 inhibitor). 3-Isobutyl-1-methylxanthine inhibits all PDE in both the oocyte and CC, whereas cilostamide inhibits PDE3 only in the oocyte, allowing a gradual reversal of inhibition. Bovine oocytes (n = 363) were obtained by transvaginal ultrasound-guided aspiration of both Brahman and Angus cattle over 4 collection days. Oocytes from each cow were divided into 2 groups. The first group was placed in standard 23-h IVM medium composed of TCM-199 supplemented with 10% fetal bovine serum, sodium pyruvate, penicillin and streptomycin, glutamine, and FSH, and cultured in 5% CO2 at 39°C. A subset of oocytes was removed from maturation at 8, 13, 18, and 23 h. The second group was placed into a pre-IVM medium of HEPES-TALP supplemented with 100 μM FSK and 500 μM IBMX for 2 h at 39°C, and then moved into standard maturation medium supplemented with 20 μM cilostamide for 31 h (5% CO2, 39°C). Oocytes were sampled at 8, 13, 18, 23, 28, and 33 h. Oocytes were stained with 1% orcein and nuclear status was examined for each sample time (Table 1). Data were analysed using a chi-squared test. At 8 h, there was a significant difference (P < 0.001) between GV stage of IVM and extended IVM (7.1 v. 73.2%), and between metaphase I (MI) stage IVM and extended IVM (76.2 v. 4.9%). At the 23-h time sample, there was a significant difference between metaphase II (MII) IVM and MII extended IVM (78.9 v. 30.6%; P < 0.001). There was also a significant difference between MII oocytes at 23 h IVM and MII oocytes at 33 h extended IVM (78.9 v. 33.3%; P < 0.001). These results are consistent with the hypothesis that cAMP modulators slow the nuclear maturation process. However, results also suggest that the inhibitory effect of the cAMP modulators is not completely reversible. Oocytes appear to arrest at MI by 23-h extended IVM and do not progress to MII at the same rate as standard IVM.

Table 1.Nuclear status of bovine oocytes after standard IVM and extended IVM with cAMP modulators
161 USE OF FORSKOLIN TO DELAY MEIOSIS AND PRODUCE IN VITRO BOVINE EMBRYOS
Authors: Paschoal D. , Maziero R. , Sudano M. , Guastali M. , Vergara L. , Crocomo L. , Lima-Neto J. , Magalhães L. , Rascado T. , Martins A. , Landim-Alvarenga F.
Published: December 2013

The maintenance of oocytes in germinal vesicle (GV) stage for a few hours could result in more competent oocytes for use in biotechnology. This study aimed to show if the use of forskolin is able to inhibit and reverse the maturation in bovine oocytes, producing a higher rate of in vitro embryos without apoptosis rates. Eight replicates in total were performed. Nellore oocytes were matured in TCM-199 and to delay meiosis, the oocytes (n = 584) were maintained for 6 h in medium in presence of 0.025, 0.05, or 0.1 mM Forskolin. Then, the oocytes were cultured for 18 h in agent-free medium to resume meiosis. After resumption of meiosis, the oocytes (n = 336) were stained with Hoechst 33342 to evaluate the state of the nucleus: germinal vesicle (GV), germinal vesicle breakdown (GVBD), metaphase I (MI), metaphase II (MII), or degenerated or unidentified (D/U). Then (Day 0) oocytes were fertilized in human tubal fluid (Irvine, New Zealand) and the presumed zygotes were culture in SOFaa + 0.6% BSA + 2.5% FCS until Day 7, when the blastocyst (n = 177) rate was evaluated. Apoptosis in blastocysts was assessed by terminal deoxynucleotidyl transferase uracil nick-end labeling (TUNEL) reaction. Data were analysed by ANOVA, followed by Tukey test using the general linear model (PROC GLM) of SAS (SAS Institute Inc., Cary, NC, USA). The level of significance adopted was 5%. There were no statistical differences in state of the nucleus, only in MI (Control = GV: 0.0, GVBD: 0.8, MI: 8.3a, MII: 67.7, D/U: 7.3; F 0.025 mM = GV: 2.8, GVBD: 0.7, MI: 20.8ab, MII: 67.7, D/U: 8.9; F 0.05 mM = GV: 0.0, GVBD: 4.4, MI: 15.8ab, MII: 65.9, D/U: 13.7; and F 0.1 mM = GV: 0.0, GVBD: 1.0, MI: 34.1b, MII: 50.2, D/U: 14.6; P < 0.05). There were no statistical differences in blastocyst rate (Control: 36.7, F 0.025 mM: 32.6, F 0.05 mM: 29.2 and F 0.1 mM: 25.1 – P > 0.05). But when we analysed the apoptosis rate, differences were found among groups: (Control: 12.1a, F 0.025 mM: 12.9a, F 0.05 mM: 13.5a and F 0.1 mM: 30b; P < 0.05). Although Forskolin was able to inhibit meiosis and produce embryos at the same rates as controls, the higher dosage of this drug damaged the embryos.
The authors acknowledge FAPESP 10/50410-2 for support.
163 EFFECTS OF DIFFERENT IN VITRO MATURATION SYSTEMS ON EMBRYO DEVELOPMENT IN BOVINE PREPUBERTAL AND ADULT DONORS
Authors: Bernal S. M. , Heinzmann J. , Herrmann D. , Baulain U. , Lucas-Hahn A. , Niemann H.
Published: December 2013

Prepubertal bovine females have been suggested as a source of oocytes in order to accelerate genetic gain and decrease the generation interval. However, prepubertal oocytes have a lower developmental competence than their adult counterparts. In vitro maturation (IVM) systems using cyclic AMP (cAMP) regulators and 30-h culture have been suggested to improve blastocyst in vitro production rates from bovine oocytes (Albuz et al., 2010). The present study evaluated the effects of an addition of the cAMP modulators forskolin, 3-isobutyl-1-methylxanthine (IBMX), and cilostamide during extended IVM on blastocyst yields and gene expression in prepubertal and adult bovine females. Holstein-Friesian donors were submitted to ovum pick-up twice per week. Oocytes from groups of 12 animals, including lactating cows (>2 lactations) and prepubertal donors (6–10 months old) were used in the following treatment groups: TCM24 (24-h IVM, routine protocol/control), cAMP30 (2-h pre-IVM culture using forskolin-IBMX and 30-h IVM adding cilostamide), DMSO30 [2-h pre-IVM culture and 30-h IVM with dimethyl sulfoxide (DMSO)/vehicle control]. In vitro-matured oocytes were fertilized and presumptive zygotes were cultured in vitro to assess embryo development. In vivo blastocysts were produced from superovulated cows and used for gene expression analysis. Cleavage rates, blastocyst formation, and mRNA abundance of selected genes were evaluated. The Glimmix procedure from SAS/STAT (SAS Institute Inc., Cary, NC, USA) was performed to compare blastocyst and cleavage rates. One-way ANOVA was implemented to evaluate gene expression. A total of 793 oocytes from the different sources were submitted to the IVM treatments. Cleavage rates (prepubertal donors: 64.6 ± 4%, 59.1 ± 6.4%, 53 ± 4.4%, cows: 55.1 ± 4.3%, 59 ± 6.5%, 50.8 ± 4.4%, for TCM24, cAMP30, and DMSO30, respectively; P > 0.05) and blastocyst/zygotes rates (prepubertal donors: 27 ± 6%; 21.8 ± 3.5%; 17.6 ± 2.4%; cows: 28 ± 3.3%; 27.7 ± 2.9%; 22.7 ± 3.2% for TCM24, cAMP30, and DMSO30, respectively; P > 0.05) did not differ among in vitro treatments. The mRNA relative abundance of the EGR1 gene was down-regulated 6-fold in all in vitro-produced blastocysts compared with their in vivo counterparts (P < 0.05). Gene expression profiles for SLC2A8, DNMT3B, BCL-XL, and PRDX1 were similar in in vitro and in vivo blastocysts. These results show similar embryo production patterns in prepubertal and adult donors. Furthermore, DMSO did not show effects on embryo developmental rates when used during IVM. The gene expression levels of EGR1 confirm our recent findings in blastocysts obtained from oocytes from slaughterhouse ovaries (data not presented), showing its usefulness as an embryo quality marker. These preliminary results indicate that oocyte developmental capacity in prepubertal donors can be similar to that of the adult donors without addition of cAMP modulators.
172 DETERMINING THE REQUIREMENTS FOR LH AND FSH DURING SHEEP IN VITRO OOCYTE MATURATION
Authors: de Frutos C. , Vicente-Perez R. , Ross P. J.
Published: December 2013

In vitro maturation (IVM) of oocytes in domestic animals is a widespread practice of research and commercial relevance. Gonadotropic hormones are typically supplemented to the IVM medium to stimulate resumption of meiosis, progression to metaphase II (MII), and oocyte developmental competence. The common use of pituitary-derived products presents 2 problems: contamination from other pituitary hormones and inconsistences from batch-to-batch variation. Recombinant hormones can help circumvent these issues and identify specific gonadotropin requirements for in vitro maturation. The aim of the present study was to determine the effect of supplementing recombinant bovine LH and/or FSH (AspenBio) to the maturation of ovine oocytes in terms of cumulus expansion and progression to the MII stage. Abattoir-derived sheep cumulus–oocyte complexes (COC) were obtained from 1- to 5-mm-diameter antral follicles by ovary slicing. Oocytes with a homogeneous cytoplasm surrounded by at least 3 layers of cumulus cells were selected and cultured in serum-free IVM medium (Cotterill et al. 2012 Reproduction 144, 195–207) at 38.5°C and 5% CO2. The COC obtained from 8 replicates were allocated into 4 experimental groups: (1) no hormones; (2) 1.5 μg mL–1 recombinant bovine LH (rbLH); (3) 1.5 μg mL–1 recombinant bovine FSH (rbFSH); and (4) rbLH and rbFSH. The expansion of cumulus cells was recorded in each group after 24 h of IVM and COC classified as (1) very poor or no cumulus expansion (grade 1); (2) limited cumulus expansion (grade 2); and (3) full cumulus expansion (grade 3). Nuclear maturation in the 4 treatments was evaluated by assessing progression to the MII stage via DNA staining with Hoechst 33342 and fluorescence imaging. The effect of treatment on the observed proportion of MII oocytes was evaluated using a mixed logit model including treatment and replicate as fixed and random effects, respectively. Culture in IVM medium in the absence of gonadotropins or in the presence of rbLH resulted in poor cumulus expansion (grade 1). The supplementation of IVM medium with rbFSH (with or without rbLH) yielded a high degree of cumulus expansion (grades 2–3). Likewise, addition of rbFSH enhanced progression of oocytes to the MII stage, whereas use of rbLH, although it had an effect on progression to MII, did not augment the effect of rbFSH (Table 1). These results indicate that rbFSH is necessary and sufficient to induce sheep oocyte maturation in a high proportion of oocytes.

Table 1.Cumulus expansion and oocyte nuclear stage after IVM
174 RECOVERY OF LONG-BEAKED COMMON DOLPHIN OOCYTES FROM KOREAN WATERS
Authors: Hwang S. U. , Jeon Y. , Yoon J. D. , Cai L. , Kim E. , Lee S. , Hyun S. H.
Published: December 2013

The aims of this study were to collect oocytes from ovaries of Delphinus capensis (long-beaked common dolphin) and to examine the morphological characteristics of their reproductive organ. Female genital organs were collected from 2 incidentally caught Delphinus capensis (ID-96: estimated 5–6 years, and ID-97: estimated 7–8 years). Collected ovaries were transported to the laboratory over 3.5 h in 0.9% saline at 39°C. To perform assisted reproductive techniques in wild animals, it is important to maximize the number of oocyte recovered per ovary. In this study, Delphinus capensis oocytes were collected by 2 methods: (1) aspiration of visible follicles (2 to 3 mm in diameter) and (2) remnant dissection, in which the ovary is finely dissected. The collected cumulus–oocyte complexes (COC) were separated by ovary of origin and collection method. Oocytes were subjected to in vitro maturation (IVM). Immature oocytes were placed into IVM medium [TCM-199 supplemented with 10% (vol/vol) fetal bovine serum, 0.5 IU mL–1 LH, and 0.5 IU mL–1 porcine FSH] in the 4-well dish for 120 h at 37°C in 5% CO2 in a humidified atmosphere. The uterus type was observed to be a uterus bicornis. Morphology of ovary was similar to the bovine ovary among land animals. In total, 114 oocytes were obtained. From the ovary of ID-97, the number of oocytes recovered by aspiration and ovary dissection were 15 and 57, respectively. However, only 42 oocytes were recovered by ovary dissection from the ovary of ID-96. The number of oocytes recovered per ovary by dissection (49.5 ± 7.5) was higher than that by the aspiration (7.5 ± 7.5) method, but not significantly different (P = 0.06). For accurate statistical analysis, additional trials will be performed. Most oocytes had either no cumulus cells or had only 1 to 2 layers attached to the zona pellucida enclosing a homogeneous cytoplasm. After IVM, all oocytes were at the metaphase I stage, with even fewer attached cumulus cells than at recovery. To summarise, we describe the gross morphology of the female reproductive tract of the long-beaked common dolphin and determined that dissection of the ovary is required for maximal recovery of oocytes.
This work was supported, in part, by a grant from the Next-Generation Bio Green 21 Program (No. PJ00956901), Rural Development Administration, and the National Research Foundation of Korea Grant funded by the Korean Government (NRF-2012R1A1A4A01004885, NRF-2013R1A2A2A04008751), Republic of Korea.
177 EFFECT OF DIFFERENT FERTILIZATION MEDIA ON IN VITRO BOVINE EMBRYO DEVELOPMENT USING FLOW-CYTOMETRICALLY-SORTED FEMALE SPERM
Authors: Ferré L. B. , Bogliotti Y. S. , Chitwood J. L. , Ross P. J.
Published: December 2013

High demand exists for in vitro-derived bovine embryos fertilized with female sex-sorted sperm by seedstock and commercial cattle producers. The aim of this study was to evaluate different fertilization media on in vitro fertilization performance using female sex-sorted semen. Ovaries were collected from a slaughterhouse and oocytes aspirated from 2- to 6-mm follicles. Cumulus-oocyte complexes containing compact and complete cumulus cell layers were selected and matured in groups of 50 cumulus-oocyte complexes in 400 μL of M199 medium supplemented with ALA-glutamine (0.1 mM), Na pyruvate (0.2 mM), gentamicin (5 μg mL–1), epidermal growth factor (50 ng mL–1), oFSH (50 ng mL–1), bLH (3 μg mL–1), cysteamine (0.1 mM), and 10% fetal bovine serum for 22 to 24 h. Fertilization (Day 0) was carried out using female sex-sorted semen selected with a discontinuous density gradient and diluted to a final concentration of 1 × 106 sperm mL–1. Three different fertilization media, M199 (Gibco 11043–023, Grand Island, NY, USA), SOF (Tervit et al. 1972 J. Reprod. Fertil. 30, 493–497), and TALP (Parrish et al. 1988 Biol. Reprod. 38, 1171–1180), were assayed along with 3 female sex-sorted bulls. All fertilization media were supplemented with fructose (90 μg mL–1), penicillamine (3 μg mL–1), hypotaurine (11 μg mL–1), and heparin (20 μg mL–1). After 18 h, presumptive zygotes were denuded and cultured in groups of 15 to 20 in 50-μL drops of KSOM-BSA for 9 days. On Day 3, 3% fetal bovine serum was added. Low oxygen tension (5% O2) was used for the entire culture period. On Days 7 and 9 blastocysts and hatched embryos, respectively, were morphologically evaluated according to IETS standards and recorded. Results are shown in Table 1. Data was compared by chi-squared analysis. Fertilization media affected cleavage rate and subsequent embryo development, quality, and hatching ability. The SOF and TALP fertilization media produced significantly more and higher quality embryos than M199.

Table 1.In vitro fertilization performance after oocyte fertilization using sex-sorted sperm