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Recent in vitro follicle culture (IVFC) studies in caprine have yielded lower maturation rates using late preantral follicles compared to early antral follicles. Thus, research focusing on developing stage-specific customized culture systems able to improve the efficiency of IVFC for late preantral follicles are warranted. This study aimed to compare the morphometric features, estradiol production, and gene expression between early antral caprine follicles produced in vitro and in vivo. In vitro-derived early antral follicles were produced after a 6-day in vitro culture of late preantral follicles, while in vivo-derived early antral follicles were yielded immediately after isolation from the ovaries; antral follicles were, thereafter, cultured for 18 days. In vitro-derived antral follicles were cultured either in a medium developed for preantral follicles (PF medium) or in a medium developed for antral follicles (AF medium). In vivo-derived early antral follicles, on the other hand, were cultured in AF medium (Control treatment). Results demonstrated that in vitro-derived antral follicles cultured in PF medium produced higher estradiol concentration, and m-RNA expression for matrix metalloproteinase-9 (MMP-9), and insulin receptor when compared to both in vitro- and in vivo-derived antral follicles cultured in AF medium. Remarkably, in vitro-derived antral follicles cultured in PF medium had similar MII and oocytes ≥110 μm rates compared with in vivo-derived antral follicles (Control treatment). In conclusion, when cultured in a single and appropriate medium (i.e., PF medium), in vitro-derived early antral follicles had comparable oocyte maturation rates to the in vivo-derived early antral follicles., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of this work., (Copyright © 2022 Elsevier Inc. All rights reserved.)

This study aimed to evaluate the role of anethole during the in vitro culture of caprine early antral follicles. Early antral follicles were isolated from caprine ovaries and cultured for 18 days without (control) or with anethole (300 µg/ml). After culture, the cumulus-oocyte complexes were subjected to in vitro maturation, followed by parthenogenetic activation or in vitro fertilization (IVF) and embryo culture. Follicular walls were used for the quantification of messenger RNA (mRNA) of CYP19A1, CYP17, MMP-9, TIMP-2, Bax, and Bcl-2 genes, and culture medium was used for evaluation of ferric reducing antioxidant power (FRAP) and estradiol levels. After in vitro follicle culture (IVFC), anethole induced higher total antioxidant capacity, that is, it produced higher FRAP levels, reduced the Bax/Bcl-2 ratio, and increased the levels of mRNA for CYP19A1 and CYP17, which was associated with a greater estradiol production (p < .05). Also, anethole improved the ability of oocytes to resume meiosis and reach metaphase II stage, as well as yielded higher (p < .05) embryo production (e.g., morulas and blastocysts) in both parthenogenetic activation and IVF techniques. One pregnancy (Day 30) was obtained from IVFC with anethole. In conclusion, anethole promoted in vitro growth and maturation of goat early antral follicles and oocytes and enabled embryo production. Furthermore, this study reports, for the first time in goats, a pregnancy after IVF using oocytes originated from early antral follicles grown in vitro., (© 2020 Wiley Periodicals LLC.)

Oxidative stress is one of the most detrimental factors that affect oocyte developmental competence and embryo development in vitro. The impact of anethole supplementation to in vitro maturation (IVM) media on oocyte maturation and further bovine in vitro embryo production was investigated. Oocytes of slaughterhouse-derived bovine ovaries were placed in IVM with anethole at different concentrations of 30 (AN30), 300 (AN300), and 2000 μg/mL (AN2000), or without (control treatment). The oocytes were assessed for maturation rates, and for reactive oxygen species (ROS) and ferric reducing antioxidant power (FRAP) levels, and mitochondrial membrane potential. Embryo development was assessed by cleavage and blastocyst rates, and embryo cell number. The percentage of metaphase II oocytes were similar among the treatments (range, 77%-96%). Anethole at 300 μg/mL was the only treatment that yielded higher cleavage and embryo development (morula and blastocyst) rates compared to the control treatment. The ROS production in the oocytes after maturation did not differ among treatments. However, oocytes treated with anethole at 300 μg/mL had higher (P < .05) FRAP and mitochondrial membrane potential compared to the control treatment. Furthermore, AN300 treatment increased (P < .05) the average number of total cells in blastocysts compared to the control and AN30 treatments. The use of anethole at 300 μg/mL during IVM is suggested to improve the quantity and quality of bovine embryos produced in vitro. The beneficial effects of anethole on embryonic developmental competence in vitro seems to be related to its capacity to regulate the redox balance and improve mitochondrial function in oocytes and embryos.

This study investigated the effect of Folliculinum 6 cH on the oocyte meiosis resumption and viability rates, progesterone production and mitochondrial activity after in vitro maturation of cumulus-oocyte complexes (COCs) in sheep. Sheep ovaries were collected at a local slaughterhouse and COCs were recovered by slicing technique. The selected COCs were maturated in TCM199 (Control treatment), or control medium supplemented with 0.05% ethanol (v/v) (the vehicle of the homeopathic preparation - Ethanol treatment) or with Folliculinum 6 cH . After 24 h of in vitro maturation (IVM), oocytes were mechanically denuded and incubated with Hoechst 33342 and MitoTracker (0.5 μM) Orange CMTMRos for analysis of viability and chromatin configuration, and mitochondrial activity, respectively. The results showed that Folliculinum 6 cH addition increased oocyte degeneration and reduced meiotic resumption compared to the control (P < 0.05). Interestingly, the percentages meiotic resumption and oocyte maturation were lower in the Folliculinum 6 cH treatment compared to its vehicle (Ethanol treatment) (P < 0.05). On the other hand, when the treatments were compared, higher mitochondrial activity was observed in the Ethanol treatment (P < 0.05). In conclusion, contrary to its vehicle, the addition of Folliculinum 6 cH to the IVM medium promoted oocyte degeneration and affected negatively the mitochondrial distribution, impairing meiosis resumption., Competing Interests: Conflicts of interest: The authors have no conflict of interest to declare., (Copyright © The Author(s).)

The present study aimed to evaluate the effect of three culture systems on caprine primordial follicle activation in vitro: follicles cultured either in the isolated form within alginate (Isolated follicles + Alginate treatment), or enclosed in ovarian tissue (in situ), with or without alginate (Fragment + Alginate, and Fragment alone treatments, respectively). After culture, the Isolated follicles + Alginate treatment presented a percentage of morphologically normal follicles (MNF) similar to both the non-cultured control and the Fragment Alone treatments. Nevertheless, Fragment + Alginate treatment showed a significant reduction in the number of MNF when compared to the other treatments. Regarding follicle development, our results showed that regardless of the alginate, the presence of ovarian tissue limited primordial follicle activation during in vitro culture. Remarkably, the Isolated primordial follicle + Alginate treatment was the only one that significantly promoted follicle activation and increased both follicle and oocyte diameters during IVFC, pointing out a higher cell proliferation. In conclusion, the presence of ovarian tissue with or without alginate limited follicle development (activation) after culture. Nevertheless, when primordial follicles were isolated and encapsulated in alginate they presented suitable survival rates, higher rates of follicle activation and continued to grow throughout the culture period., (© 2020 Blackwell Verlag GmbH.)

The objective of this study was to determine whether preantral follicles cultured in vitro for 7 days within ovine ovarian cortical strips could be isolated at the secondary follicles (SF) and grown until antral stage during an additional 6 days period of in vitro culture in the presence of aqueous extract of Justicia insularis. Fresh ovarian fragments from 16 adult sheep were fixed for histological analysis (Control 1) or in vitro cultured individually in α-MEM + supplemented with 0.3 mg/ml J. insularis (Step 1) for 7 days. Part of the fragments then were fixed for histological analysis (in vitro culture group). Remaining fragments were exposed stepwise to increasing trehalose concentrations before immediate isolation of SF and viability assessment (Control 2) or after 6 days of culture in α-MEM ++ supplemented with 0.3 mg/ml J. insularis (Step 2). In Step 1, percentage of follicular activation was 80%. In Step 2, a significant increase (p < 0.05) in follicular diameter and antrum formation within 6 days in vitro culture of isolated follicles was achieved. The total antioxidant capacity from both steps significantly increase (p < 0.05) from day 2 to day 6. Confocal analysis of oocytes showed 57.14% oocytes with homogeneous distribution and 42.86% with peri-cortical distribution. In conclusion, SF can be successfully isolated from sheep ovarian cortex after 7 days of culture and are capable of surviving and forming an antral cavity if cultured in vitro for an additional 6 days in the presence of 0.3 mg/ml J. insularis., (© 2019 Blackwell Verlag GmbH.)

Oxidative stress is one of the most detrimental factors that affect oocyte developmental competence and embryo development in vitro. The impact of anethole supplementation to in vitro maturation (IVM) media on oocyte maturation and further bovine in vitro embryo production was investigated. Oocytes of slaughterhouse-derived bovine ovaries were placed in IVM with anethole at different concentrations of 30 (AN30), 300 (AN300), and 2000 μg/mL (AN2000), or without (control treatment). The oocytes were assessed for maturation rates, and for reactive oxygen species (ROS) and ferric reducing antioxidant power (FRAP) levels, and mitochondrial membrane potential. Embryo development was assessed by cleavage and blastocyst rates, and embryo cell number. The percentage of metaphase II oocytes were similar among the treatments (range, 77%-96%). Anethole at 300 µg/mL was the only treatment that yielded higher cleavage and embryo development (morula and blastocyst) rates compared to the control treatment. The ROS production in the oocytes after maturation did not differ among treatments. However, oocytes treated with anethole at 300 µg/mL had higher ( P < .05) FRAP and mitochondrial membrane potential compared to the control treatment. Furthermore, AN300 treatment increased ( P < .05) the average number of total cells in blastocysts compared to the control and AN30 treatments. The use of anethole at 300 μg/mL during IVM is suggested to improve the quantity and quality of bovine embryos produced in vitro. The beneficial effects of anethole on embryonic developmental competence in vitro seems to be related to its capacity to regulate the redox balance and improve mitochondrial function in oocytes and embryos.

SummaryThe objectives were to develop an effective protocol for transfection of ovine secondary follicles and to assess the effect of attenuating aquaporin 3 (AQP3) using a small interfering RNA (siRNA-AQP3) on antrum formation and follicular growth in vitro. Various combinations of Lipofectamine® volumes (0.5, 0.75 or 1.0 µl), fluorescent oligonucleotide (BLOCK-iT ™) concentrations (3.18, 27.12 or 36.16 nM) and exposure times (12, 14, 16, 18 or 20 h) were tested. The BLOCK-iT™ was replaced by siRNA-AQP3 in the transfection complex. Ovine secondary follicles were isolated and cultured in vitro for 6 days using standard protocols. Follicles were transfected on day 0 or 3 or on both days (0 and 3) and then cultured for an additional 3 or 6 days. As revealed by the fluorescence signal, the Lipofectamine®/BLOCK-iT™ complex (0.75 µl + 27.12 nM by 12 h of incubation) crossed the basement membrane and granulosa cell and reached the oocytes. In general, the rate of intact follicles was higher and the rate of antrum formation was lower in transfected follicles compared with control follicles. In conclusion, ovine secondary follicles can be successfully transfected during in vitro culture, and siRNA-mediated attenuation of AQP3 gene reduced antrum formation of secondary follicles.