Bovine oocyte developmental competence and gene expression following co-culturing with ampullary cells: An experimental study

Background: There is no sufficient information on the impact of bovine ampullary oviductal epithelial cells (BAOECs) on in vitro oocyte maturation competence and gene expression. Objective: This study aimed to examine the oocyte developmental competence following co-culturing with a monolayer of fresh and frozen-thawed ampullary cells. Materials and Methods: Bovine cumulus-oocyte complexes (COCs) were distributed into three groups: control group; where in COCs were cultured in cell-free media for 24 hr and FML and FTML groups in which the COCs were cultured in maturation media for 18 hr and then transferred into a media containing fresh and frozen-thawed BAOECs monolayer, respectively (BAOECs were extracted from the oviducts of slaughtered cattle and were then cultured freshly or frozen-thawed) for a further 6 hr. After 24 hr, the expanded COCs were evaluated for nuclear maturation, fertilization rate, and gene expression (GDF9, StAR, CASP3, and FSHr). Results: Nuclear maturation rate in the FTML group was significantly higher than the control group (p = 0.02). The fertilization rate of FTML group was significantly higher than the control and FML groups (p = 0.05 and p = 0.03, respectively). In terms of gene expression, GDF9 were upregulated in the presence of the BAOECs during the last 6 hr of the in vitro maturation (p < 0.001). Furthermore, the expression of the StAR gene in the FTML group was higher than the other groups (p = 0.02). Conclusion: Ampullary cells co-culturing (especially frozen-thawed cells) for in vitro maturation of bovine oocytes yields encourages the results and demonstrates the beneficial effect of co-culture on gene expression and developmental competence. Key words: Ampulla, Bovine, Fertilization, Gene expression, IVM

Niacin improves maturation and cryo-tolerance of bovine in vitro matured oocytes: An experimental study

Background: Nicotinic acid (niacin) is a broad-spectrum lipid-modifying agent that has potent antioxidant properties and reduces the production of lipid peroxidation. Objective: The purpose of the present study was to investigate the maturation, embryo development and cryo-tolerance merit, and levels of malondialdehyde (MDA), total oxidant status, and total antioxidant capacity following the supplementation of bovine oocytes maturation medium with different concentrations of niacin. Materials and Methods: Immature cumulus-oocyte complexes were cultured in tissue culture medium-199 maturation media supplemented with 0, 100, 200, and 400 µM niacin under a standard in vitro culture condition. After 24 hr of culture, the nuclear maturation rate was assessed. Then, two groups of immature cumulus-oocyte complexes were cultured in TCM-199 either with or without 400 µM niacin and evaluated for embryo development. Also, matured cumulus-oocyte complexes in both groups were frozen using a standard vitrification procedure. After vitrification, oocytes were warmed in two steps and evaluated for embryo development. In addition, the level of total antioxidant capacity, total oxidant status, and MDA were measured. Results: The results indicated that although the treatment with 400µM niacin increased in vitro nuclear maturation (87.6 ± 5.3), it did not improved the embryo development to the blastocyst stage. Higher cleavage and blastocyst rates were observed in vitrified oocytes that were cultured with supplemented 400 µM niacin compared to the control group (without niacin) (53.6 ± 2.7 and 10.6 ± 1.6 vs. 46.2 ± 4.1 and 6.3 ± 2.4, respectively). Also, the addition of 400 µM niacin to the maturation media could decrease MDA levels after maturation. Conclusion: Niacin could improve the quality of in vitro embryo production (IVP) embryos and tolerance of bovine oocytes to vitrification. Key words: Bovine, Embryonic development, Niacin, Oocytes, Vitrification

Extracellular vesicles from follicular and ampullary fluid isolated by density gradient ultracentrifugation improve bovine embryo development and quality

Extracellular vesicles (EVs) have been isolated from follicular (FF) and ampullary oviduct fluid (AOF), using different isolation methods. However, it is not clear whether different purification methods can affect the functionality of resulting EVs. Here, we compared two methods (OptiPrep (TM) density gradient ultracentrifugation (ODG UC) and single-step size exclusion chromatography (SEC) (qEV IZON (TM) single column)) for the isolation of EVs from bovine FF and AOF. Additionally, we evaluated whether the addition of EVs derived either by ODG UC or SEC from FF or AOF during oocyte maturation would yield extra benefits for embryo developmental competence. The characterization of EVs isolated using ODG UC or SEC from FF and AOF did not show any differences in terms of EV sizes (40-400 nm) and concentrations (2.4 +/- 0.2 x 10(12)-1.8 +/- 0.2 x 10(13) particles/mL). Blastocyst yield and quality was higher in groups supplemented with EVs isolated from FF and AOF by ODG UC, with higher total cell numbers and a lower apoptotic cell ratio compared with the other groups (p < 0.05). Supplementing in vitro maturation media with EVs derived by ODG UC from AOF was beneficial for bovine embryo development and quality

Factors associated with variation in the superovulatory response of cattle

Kafi, M., McGowan, M.R., 1997. Factors associated with variation in the superovulatory response of cattle. Anim. Reprod. Sci. Variability in the superovulatory response of cattle is still one of the major limiting factors in extensive usage of embryo transfer technology. A variety of approaches including recent attempts to eliminate the suppressive effect of the dominant follicle have been used to reduce the unpredictability of the superovulatory response of cattle. The development of techniques such as transrectal ultrasonography, have enabled a re-evaluation of ovarian dynamics during superovulation of cattle. In addition, advances in reproductive hormone assays have increased knowledge of the mechanisms controlling follicular development, ovulation and corpus luteum function. This review focuses on the current understanding of factors affecting the superovulatory response of cattle. Also, abnormalities of ovulation and endocrine disorders that may occur during superovulation are reviewed

Seroprevalence of Q fever in sheep and goat flocks with a history of abortion in Iran between 2011 and 2012

The purpose of this study was to estimate the seroprevalence of Coxiella burnetii infection in sheep and goat flocks with a history of abortion in different areas of Iran. One thousand and one hundred ovine and 180 caprine samples from 43 sheep and goat flocks in four counties located in the Northeast (Mashhad), Central (Isfahan), Western (Arak), and Southwest (Shiraz) Iran were collected randomly between March 2011 and April 2012. The CHEKIT Q fever ELISA kit was used to identify specific antibodies against C. burnetii in sheep and goats. The results showed that the overall seroprevalence of C. burnetii in sheep and goats was 19.5% and 27.2%, respectively. There was a significant difference in seropositivity between sheep and goats (P<0.05). Central Iran significantly had the highest prevalence among the studied areas, especially in goat coxiellosis (23.8% and 40.8% in sheep and goats, respectively). The lowest prevalence in sheep was 12.8% in Northeast Iran while in Western Iran C. burnetii antibodies were absent in goats. The higher prevalence of Q fever in Central Iran may be partly due to persistent favourable conditions to spread C. burnetii in this area including drought and dust storms that originated from neighbouring Iraq and Kuwait. In conclusion, the present study demonstrated the relatively high prevalence of Q fever in sheep and goat flocks with a history of abortion. Therefore, Q fever could be responsible for considerable numbers of ovine and caprine abortions in Iran

Effects of anestrus dog serum on superovulation in rats and mice

Objective: To study the effects of anestrus dog serum in rodents (contains high amount of FSH) compared with two common superovulatory programs.Methods: Rats (n=30) at diestrus phase were evenly divided into pregnant mare serum gonadotrophins (PMSG) group (administrated with 30 IU PMSG, and 48 h later following by 25 IU hCG), recombinant follicle stimulating hormone (rFSH) group (reducing dose every 12 h from 5 to 1 IU, then following by 25 IU hCG) and anestrus dog serum group (reducing dose every 12 h from 0.6 to 0.1 mL, then following by 25 IU of hCG). Mice (n=30) were also evenly divided into PMSG group (5 IU PMSG used at 13 pm, and 48 h later following by 5 IU of hCG), rFSH group (from 13 pm, reducing dose every 12 h from 2.5 to 0.5 IU, then following by 5 IU hCG) and anestrous dog serum group (from 13 pm, reducing dose every 12 h from 0.100 to 0.025 mL, then following by 5 IU hCG). Mice and rats placed with males for 24 h after last injection. Histology samples of ovaries were prepared and the numbers of corpus lutea were counted on day 14 after mating.Results: In mice, the differences among mean number of corpus lutea in all groups (P=0.01) and between FSH and dog serum group were significant (P=0.000 7). But no significant differences were found between the mean number of corpus lutea in dog serum and PMSG, or between FSH and PMSG groups. In rats, mean number of corpus lutea were significant differences among three groups (P=0.01), and between PMSG and dog serum groups (P=0.02).Conclusions: Superovulatory response in anestrus dog serum group is similar to PMSG group in mice, which is relatively similar to FSH in rats

Assessment of cyclic behavior and performance of hybrid linked-column steel plate shear wall system

An innovative hybrid linked columns steel plate shear wall (HLCS) system provided, and its cyclic behavior and energy absorption are investigated by finite element method in this study. The objective of the designed HLCS system was to reduce or possibly prevent damage to the SPSW at low and medium seismic levels by focusing the seismic damage to interchangeable link beams (the energy dissipation components of the presented HLCS system). In this study, the cyclic behavior and energy dissipation of HLCS systems were investigated using numerical methods. To evaluate the hysteresis behavior and energy absorption of the proposed HLCS system, parametric studies were performed. Also, the accuracy of finite element models was evaluated by comparing test results that showed the good accuracy of finite element models in predicting the specimens' hysteresis behavior and failure modes. Due to the failure mechanisms, the coupling ratio amounts meaningfully affect the onset of the first surrender mechanism between the infill steel plate and link beams. In general, by increasing the number of link beams in the floor, the ultimate shear force to the weight ratio of the structure was increased. Also, the type of beam in terms of flexural and shear behavior did not significantly affect the ratio of base shear force to the structure weight. The proposed HLCS system has increased the ratio of base shear force to the weight by an average of 4%–27%, indicating that this system is economically comparable to the SPSW systems. Moreover, the energy dissipation in the HLCS system exhibited a 14%–91% enhancement compared to the SPSW system