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This study examined caprine follicular development in different concentrations of alginate matrix to determine the optimal conditions for culture. Caprine preantral follicles were cultured in a two-dimensional system (control) or a three-dimensional encapsulated system in 0.25%, 0.5%, or 1% alginate (ALG 0.25, ALG 0.5, and ALG 1, respectively). A higher percentage of morphologically normal follicles developed in ALG 0.5 and ALG 1 than in ALG 0.25 or the control (P < 0.05). The rate of antrum formation, however, was higher in ALG 0.25 than in ALG 0.5 and ALG 1 conditions (P < 0.05), but similar to the control. Follicles cultured in ALG 0.25 had higher growth rates and meiotic resumption than those cultured in ALG 0.5, ALG 1, or the control (P < 0.05). Moreover, follicles cultured in ALG 0.25 had higher levels of estradiol and progesterone than those cultured in ALG 0.5, ALG 1, or the control, as well as higher levels of CYP19A1 and HSD3B mRNA. In conclusion, a three-dimensional system that uses ALG 0.25 fosters the in vitro development of caprine preantral follicles and increases the rate of meiotic resumption., (© 2014 Wiley Periodicals, Inc.)

This study verified the in vitro effects of IGF-1, FSH or both on caprine preantral follicle development and mRNA levels encoding IGF-1, IGFR-1 and FSHR. Secondary follicles were cultured for six days with FSH, IGF-1 or IGF-1+FSH. The results showed that IGF-1 and/or FSH addition did not influence follicular development for six days. The interaction between IGF-1 and FSH increased the mRNA levels of IGF-1 and FSHR, and FSH increased the expression of the IGFR-1 mRNA. Thus, IGF-1 and/or FSH increased IGF-1, IGFR-1 and FSHR mRNA levels in in vitro cultured caprine secondary follicles, but they did not influence their development after six days of in vitro culture., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

The aims of this study were to investigate the expression levels of mRNA for platelet-derived growth factor (PDGF) receptors (PDGFR-α and -β) in caprine follicles at different developmental stages and to evaluate the influence of PDGF on the in vitro development of pre-antral follicles. For this, goat primordial, primary and secondary follicles, as well as small (1-3 mm) and large (3-6 mm) antral follicles, were obtained, and PDGFR-α and -β mRNA levels were quantified by real-time PCR. Furthermore, pre-antral follicles (≥ 200 μm) were isolated from goat ovaries and cultured for 18 days in α- minimum essential medium supplemented with PDGF at 50 or 100 ng/ml, containing or not FSH. Real-time PCR showed highest PDGFR-α mRNA levels in secondary follicles, while PDGFR-β mRNA levels were highest in primary follicles onwards. Both receptors showed higher mRNA levels in granulosa/theca cells from small and large antral follicles than in their corresponding cumulus-oocyte complexes. In culture, the percentage of antrum formation was significantly higher in 100 ng/ml PDGF compared with the same PDGF concentration associated with FSH. After 18 days, PDGF in both concentrations associated with FSH promoted follicular growth significantly higher than the control. Moreover, the addition of FSH to 50 ng/ml PDGF positively influenced the follicular growth when compared with the same PDGF concentration in the absence of FSH. In conclusion, PDGF is important for early goat folliculogenesis, because the presence of PDGFR-α and -β mRNA was detected in all follicular categories, and PDGF associated with FSH stimulated the growth of goat pre-antral follicles isolated and cultured in vitro., (© 2011 Blackwell Verlag GmbH.)

The aim of this study was to evaluate the effects of a dynamic medium containing kit ligand (KL) and follicle-stimulating hormone (FSH) on the in vitro culture of caprine preantral follicles for 16 days. Ovarian fragments were cultured in α-MEM(+) containing or not containing KL (50 ng/ml) and/or FSH (50 ng/ml) added during the first (days 0-8) and/or second half (days 8-16) of the culture period. Noncultured (control) and cultured fragments were processed for histological and ultrastructural evaluation. After 1 day of culture, only the treatments performed with KL or FSH maintained a percentage of normal follicles similar to that of the control. After 16 days, all treatments using KL until day 8 (KL/KL, KL/FSH, and KL/FSH+KL) and only FSH during the entire culture period (FSH/FSH) showed higher rates of follicular survival compared to α-MEM(+) alone. After 1 and 8 days, the treatments initially cultured with KL increased the percentage of follicular activation in comparison to α-MEM(+) alone and other treatments. The highest follicular diameter after 16 days was observed in follicles cultured with KL until day 8 followed by FSH (KL/FSH). Furthermore, this treatment promoted, as early as after 1 day of culture, an increase in oocyte growth compared to α-MEM(+) alone. Ultrastructural analysis confirmed the integrity of follicles cultured in KL/FSH after 16 days. In conclusion, a dynamic medium containing KL and FSH maintained follicular integrity and promoted follicular activation and growth during the long-term in vitro culture of caprine preantral follicles., (Copyright © 2011 S. Karger AG, Basel.)

The aims of this study were to evaluate the expression of keratinocyte growth factor (KGF) in goat ovaries and to study its effects on preantral follicle survival and development. The ovaries were used for immunohistochemistry or for in vitro culture for 1 or 7 days with KGF (0, 1, 10, 50, 100, 150, or 200 ng/mL). Noncultured (fresh control) and cultured ovarian slices were processed for histological analysis and transmission electron microscopy (TEM). The results showed that after 7 days of in vitro culture, all treatments had a significant reduction in the percentage of normal follicles compared with the fresh control. After 7 days of culture, the highest KGF concentrations (150 and 200 ng/mL) induced a significant reduction in the percentage of normal follicles compared with the tissues cultured in the absence (α-MEM(+) alone) or presence of 1, 10, and 50 ng/mL KGF. Transmission electron microscopy confirmed follicular integrity after 7 days of culture in 1 ng/mL KGF. In addition, compared with the fresh control, the percentage of growing follicles was significantly increased in all treatments after 1 or 7 days of culture. Immunohistochemical analyses showed the expression of KGF in oocytes and granulosa cells in all follicle developmental stages as well as in thecal and stromal cells. In conclusion, this study demonstrated that, at the lowest concentration (1 ng/mL), KGF maintained the ultrastructure of goat preantral follicles cultured in vitro for up to 7 days. Furthermore, the KGF protein was widely distributed in goat ovaries, especially in ovarian follicles.

This study evaluated the levels of c-kit mRNA in goat follicles and the effects of kit ligand (KL) on the in vitro development of cultured preantral follicles. Preantral follicles isolated from goat ovarian cortex were cultured for 18 days in α-MEM(+) supplemented with KL (0, 50 or 100 ng/mL) in the absence or presence of follicle stimulating hormone (FSH). Real-time PCR showed that c-kit mRNA was higher in primordial and primary follicles than in secondary stage. Regarding the culture, KL addition in the absence of FSH improved the follicular survival, antrum formation, oocyte growth and meiotic resumption. KL-positive effects were not observed in the presence of FSH. In conclusion, c-kit mRNAs are detected in all follicular categories. KL promotes the survival and antral cavity formation of caprine preantral follicles after in vitro culture, as well as the growth and meiotic resumption of their oocytes in the absence of FSH., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

The objective was to evaluate the effects of growth hormone (GH) on the survival, growth, maturation, and fertilization of oocytes derived from caprine preantral ovarian follicles cultured in vitro. Preantral follicles were isolated from the cortex of caprine ovaries and individually cultured for 18 d in the absence (control) or presence of bovine GH at concentrations of 10 or 50 ng/mL (GH10 and GH50, respectively). Follicle development was evaluated on the basis of survival, antral cavity formation, diameter increase, and the presence of healthy cumulus-oocyte complexes and mature oocytes. After culture, oocytes were subjected to in vitro maturation (IVM) and in vitro fertilization (IVF). The rate of antrum formation after Day 6 of culture was higher in both GH10 and GH50 than in the control (81.0, 92.7, and 47.6%, respectively, P < 0.05). Percentages of grown oocytes that were acceptable for IVM were also higher (P < 0.05) in GH-treated groups than in the control (54.8, 48.8, and 11.9% for GH10, GH50, and Control). A higher percentage of oocytes in the GH50 treatment underwent meiotic resumption (50.0%), produced mature oocytes, and enabled production of an embryo after IVF than in the control group (0.0%; P < 0.05). In conclusion, GH promoted in vitro growth and maturation of goat preantral follicle oocytes and enabled production of an embryo. Furthermore, this study was apparently the first to produce a caprine embryo by in vitro fertilization of oocytes derived from preantral follicles grown in vitro., (Copyright © 2011 Elsevier Inc. All rights reserved.)