Isolation and Culture of Ovine and Bubaline Small and Large Pre-antral Follicles: Effect of Cyclicity and Presence of a Dominant Follicle

Influence of phenolic flavonols (Kaempferol, Querectin and Myricetin) on the survival and growth of ovine preantral follicles and granulosa cells cultured in vitro

Study was carried out to examine the influence of plant bioactive compounds [Kaempferol (KAE), Querectin (QUE) and Myricetin (MYR)] on the survival and growth parameters of cultured ovine preantral follicles (PFs) granulosa cells (GCs) and expression of some key developmental genes. Ovine PFs were isolated from slaughterhouse derived ovaries and KAE, QUE and MYR were supplemented to the standard culture medium of GCs and PFs at concentrations of 0, 5, 10, 25, 50 and 100 μM and cultured for 5 and 7 days respectively. PFs morphological and functional parameters [follicle and enclosed oocyte growth rate, viability of follicles, antrum formation rate, oocyte maturation rate, estradiol concentration, reactive oxygen species (ROS) production] and GC growth parameters (metabolic activity, viability rate, cell number increment, ROS production) were measured after culture. Significantly higher PF growth, viability rate and estradiol concentration was observed at 10 μM, 25 μM and 10 μM concentration of KAE, MYR and QUE respectively compared to the control. ROS production was significantly decreased in the PF culture media treated with 10 μM KAE or MYR 25 μM or 10 μM QUE compared to those observed in the control group. Likewise, metabolic activity of GCs, viability rate and cell number increment cultured with KAE, MYR and QUE was significantly higher at 10, 25 and 10 μM concentrations respectively compared to those observed in control group. ROS production was significantly lower in the GC cultured with KAE, MYR and QUE at 10, 25 and 10 μM concentrations respectively compared to the control. Based on the results of the growth parameters, gene expression of PFs and GCs were studied by qPCR at selected concentrations (KAE, MYR and QUE at 10, 25 and 10 μM concentrations respectively) in the cultured PFs and GCs. Gene expression of GDF9, FGF2, CYP19A1 was significantly higher and Bax, Bcl2 expression was significantly lower in the PFs and GCs cultured with the KAE or QUE at 10 μM concentration. KAE, MYR and QUE have dose dependant responses on PFs and GCs morphological and functional parameters; however, KAE is more potent amongst the three in augmenting the ovarian functions.

Optimization and Comparison of Three-Dimensional Culture Conditions in Different Media of Coculture and Encapsulation System for In Vitro Follicular Development in Bubalus bubalis

The establishment of an in vitro culture system for complete oocyte maturation from the early stages of ovarian follicles is still a challenge. The aim of the present study was to assess the effect of different matrix with different culture media on the developmental growth of ovarian follicles in vitro. An ovarian histoarchitectural study was carried out to identify the primordial (0.027-0.039 mm), primary (0.041-0.079 mm), small preantral (0.085-0.131 mm), large preantral (0.132-0.294 mm), small antral (0.387-0.589 mm), and large antral (1.188-1.366 mm) follicles. Thus, large preantral follicles (0.2-0.3 mm) were mechanically isolated and cultured subsequently in different microconditions such as Dulbecco's modified Eagle's medium, Tissue Culture Medium-199 (TCM-199) and Opti-minimum essential medium, with same supplements where control (without matrix) was compared with matrix (coculture and encapsulation), which includes (1) buffalo fetal fibroblast cells, (2) cumulus cells, (3) ovarian mesenchymal cells, (4) collagen, (5) gelatin, and (6) Matrigel, cultured for 7 days in CO₂ incubator at 38.5°C (5% CO₂ in air). Cultured follicles were evaluated for growth rate (107.88% ± 10.24%), maturation rate (51.06% ± 6.53%), survivability rate (56.52% ± 3.42%), and antioxidant (catalase; CAT [1.58 ± 0.04 U/mg], superoxide dismutase; SOD [4.63 ± 0.05 U/mg], lactate dehydrogenase; LDH [1.48 ± 0.01 U/mg]) enzymatic activities, which showed significantly (p < 0.05) positive results in growth model with media TCM-199 than other studied groups. Furthermore, the development of large preantral follicles augmented significantly (p < 0.05) for growth rate (248.54% ± 9.51%), maturation rate (75.81% ± 7.07%), survivability rate (81.82% ± 3.02%), antioxidant (CAT [2.05 ± 0.03 U/mg], SOD [3.13 ± 0.12 U/mg], LDH [2.55 ± 0.51 U/mg]), and estradiol (175.83 ± 5.92 pg/mL) activities when they were encapsulated in Matrigel with nutritional requirements fulfilled by media TCM-199. These results provide better insight for the optimization of culture conditions for in vitro follicular development in the water buffalo, which will eventually assist in resolving the limitation of obtaining fewer competent oocytes for the embryo production in the species.

Effects of ovarian disaggregation on adult murine follicle yield and viability

Follicles are isolated from ovaries for numerous reasons, including IVM, but adult murine yields are <2 follicles mg−1. The aim of the present study was to optimise ovarian disaggregation and develop methods applicable to the rapid screening of follicle viability. Ovaries from adult mice (n = 7) were halved and disaggregated mechanically, or by using collagenase IV (Col-IV; 590 U mL−1) or animal origin-free collagenase IV (AOF) at 590 or 1180 U mL−1. Isolated follicles were stained with 4′,6′-diamidino-2-phenylindole (DAPI; nuclei), chloromethyl-X-rosamine (CMXRos; mitochondria) or fluorescein isothiocyanate-conjugated anti-α-tubulin antibody. Follicle diameters and staining were measured and analysed using ImageJ, and data analysed using GraphPad Prism. Col-IV disaggregation yielded the highest number of follicles (17 ± 10 follicles mg−1 ovarian tissue). All disaggregation methods released more secondary follicles (86 ± 20 per ovary; P < 0.05) than any other size cohort. Mechanical and Col-IV disaggregation yielded similar numbers of morphologically intact follicles, whereas AOF disaggregation caused more damage (P < 0.01). As the morphological disruption increased, DAPI and CMXRos staining decreased (P < 0.05), and tubulin localisation became more heterogeneous. Col-IV disaggregation gave the best yield of morphologically intact follicles containing viable granulosa cells. In conclusion, we improved adult murine follicle yields and applied molecular markers to assess follicle morphology, cellular cytoskeleton and mitochondrial function.

Isolation and culture of preantral follicles for retrieving oocytes for the embryo production: present status in domestic animals

The development of efficient ovarian preantral follicle (PF) isolation and culture systems provide a large number of oocytes for the manipulation and embryo production. It also helps for understanding the mechanisms of follicle and oocyte development. Isolation and culture protocols for PFs were developed for many domestic species like cattle, buffalo, sheep, goat, pig, horse, camel, dog and cats; however, embryo production from oocytes derived from in vitro grown PFs was reported only in pigs, buffalo, sheep and goat. The rate of oocyte maturation from PFs grown in vitro is low and requires considerable research. This paper presents an overview of isolation and culture systems of PFs that have been developed for domestic species (cattle, buffalo, sheep, goat, pigs, horse, camel, dog and cat) along with the current status of progress achieved in the direction of producing embryos using PFs as the source of oocyte in these species.