Competence of Swine Oocytes Matured by Three-dimensional Gonadotropin-free Co-culture

Luvoni

Comizzoli

2016

Contents The objective of the study was to assess the efficacy of coculture with conspecific cumulus‐denuded oocytes (CDOs) during in vitro maturation in a three‐dimensional system of barium alginate microcapsules on the in vitro embryo development of domestic cat cumulus–oocyte complexes (COCs). In Experiment I, COCs were cocultured with conspecific CDOs or cultured separately in a 3D system for 24 hr of in vitro maturation, before assessing the meiotic progression. In Experiment II, the in vitro fertilization of COCs and CDOs was carried out with chilled epididymal spermatozoa and the presumptive zygotes were cultured in vitro separately for 7 days in 3D microcapsules before assesment of embryonic development. The results showed that the viability was maintained and that meiosis was resumed in the 3D culture system. The presence of CDOs during in vitro maturation improved the meiotic competence of the COCs, since the proportions of telophase I/metaphase II were higher than that in the groups cultured separately. The enrichment of the maturation system by companion oocytes also enhanced the ability of COCs to develop into embryos, and increased the percentages of morula and blastoycst stages. The COCs cocultured with CDOs developed at higher rates than the COCs cultured separately and the CDOs themselves. The beneficial effects of coculture with conspecific CDOs were presumably due to the paracrine action of some secreted factors that enhanced many molecular patterns related to the complex of cumulus oophorous cells. Further investigations to understand how the 3D microenvironment can influence the features of oocytes and embryos are required.

Section: Discussionmentioning

confidence: 99%

The nuclear and developmental competence of cumulus–oocyte complexes is enhanced by three‐dimensional coculture with conspecific denuded oocytes during in vitro maturation in the domestic cat model

Luvoni

Comizzoli

2016

“…Since the follicular environment is three-dimensionally organized, the encapsulation of somatic cells, as granulosa cells (GCs), in a 3D matrix might improve their self-organization, proliferation and endocrine functions (Kossowska-Tomaszczuk et al, 2010;Vigo et al, 2005). Interesting results have been obtained with follicle-like structures applied for the in vitro culture of fresh swine and human oocytes (Munari et al, 2007;Torre et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Granulosa cells in three‐dimensional culture: A follicle‐like structure for domestic cat vitrified oocytes

Colombo

Apparício

et al. 2020

Despite being valuable resources for fertility preservation purposes of wild and endangered felids, cat (Felis silvestris catus) vitrified oocytes (VOs) poorly achieve full maturation after warming because their intrinsic competence is severely impaired by unavoidable cryodamages that also involve their surrounding cumulus cells (Luvoni, 2006). Modifications to media composition or supplementation with supporting cells alone have not led to truly satisfactory results, and therefore, since physical factors can positively influence the chemical conditions (Luvoni, Colombo, & Morselli, 2018), three-dimensional (3D) follicle-like structures could enhance meiosis resumption and further embryo development in vitro of poorly competent oocytes.

“…the proliferation and the differentiation of theca and granulosa cells, the steroid secretion and markers expression) of murine and human follicles were enhanced after in vitro culture in 3D alginate microcapsules, and the achievement of the full competence of the inner oocytes was also obtained (Xu et al., ; Xu et al., ; Shikanov et al., ). In addition, the encapsulation of human or swine oocytes in a collagen gel or in a BA capsule helped the in vitro meiosis progression until MII stage (Combelles et al., ; Munari et al., ).…”

Section: Discussionmentioning

confidence: 99%

“…The 3D environment also resulted in cell behaviour, signalling and gene expression profiles that most resemble those observed in living cells (Cukierman et al., ). It has been demonstrated that the encapsulation of follicles and oocytes in biocompatible 3D systems allows the maintenance of their physiological structure and functional integrity in different species (mouse, Pangas et al., ; human, Combelles et al., ; pig, Munari et al., ).…”

Section: Introductionmentioning

confidence: 99%

A three‐dimensional alginate system for in vitro culture of cumulus‐denuded feline oocytes

Canziani

Vigo

et al. 2016

In the case of high valuable individuals with very precious genetic material, widening the genetic pool including gametes with poor morphological characteristics, as cumulus-denuded oocytes (CDOs), could be an option. To improve the in vitro culture of low-competence feline CDOs, an enriched three-dimensional (3D) system in association with competent cumulus-oocyte complexes (COCs) was developed. For this purpose, domestic cat CDOs were cultured with or without companion COCs in the 3D barium alginate microcapsules. The overall viability and the meiotic progression of feline CDOs cocultured with COCs or cultured separately in 3D or in 2D (traditional microdrops) system were compared. The 3D system was able to support viability and meiotic resumption of the feline oocytes, as well as the 2D microdrops. In 3D microcapsules, the presence of COCs resulted in a higher viability of CDOs (91.1%, p < .05), than that obtained without COCs or in 2D microdrops (71.2% and 67.3%, respectively), but the percentages of meiotic resumption were similar of those of CDOs cultured separately (55.4% vs. 40.4%, p > .05). It is notable that the presence of CDOs seemed to enhance the meiotic progression of the associated COCs. In conclusion, the 3D barium alginate microcapsules are a suitable system for feline oocytes in vitro culture, but more specific enriched conditions should be developed to improve the CDOs full competence in vitro.