Polyacrylamide gel as a culture substrate improves in vitro oocyte growth from porcine early antral follicles

Abstract

A major difference between in vivo and in vitro follicle culture is the stiffness of the substrate in which the follicles grow. In this study, we examined the effect of polyacrylamide gel (PAG), as a culture substrate, on the development of porcine oocytes derived from early antral follicles. Oocyte-granulosa cell complexes (OGCs) were collected from the early antral follicles of gilts, and incubated individually for 14 days in a 96-well culture plate without or with PAG. We then evaluated the number of granulosa cells present in OGCs as well as the abundance of ATP, lipid, and acetylated lysine in oocytes. OGCs cultured on PAG showed significantly greater antrum formation and granulosa cell proliferation than controls cultured on standard plastic. Oocytes grown on PAG also possessed significantly larger diameter, ATP and lipid content, and lysine acetylation, as well as competence to develop to the blastocyst stage. Transcriptome analysis of the granulosa cells revealed that genes involved in follicular development and mechanosensing are up-regulated under PAG culturing conditions. Thus, in vitro culturing OGCs on PAG profoundly induced granulosa cell proliferation, resulting in improved developmental competence of the oocytes. Mol. Reprod. Dev. 84: 44-54, 2017. © 2016 Wiley Periodicals, Inc.

The effect of bpV(HOpic) on in vitro activation of primordial follicles in cultured swine ovarian cortical strips

“…The present study is limited to primordial follicle activation, and implications for later stages of follicle development have not been assessed. Several groups have conducted in vitro growth experiments with porcine oocytes obtained from pre‐antral (Tasaki, Iwata, Sato, Monji, & Kuwayama, ; Telfer, Binnie, McCaffery, & Campbell, ; Wu et al, ; Wu, Xu, & Wang, ) and early antral follicles (Cayo‐Colca, Yamagami, Phan, & Miyano, ; Itami, Shirasuna, Kuwayama, & Iwata, ; Kubo, Cayo‐Colca, & Miyano, ; Munakata, Kawahara‐Miki, Shirasuna, Kuwayama, & Iwata, ; Oi et al, ). In many cases, the meiotic competence of oocytes following in vitro growth was extremely low (Yamochi, Hashimoto, Yamanaka, Nakaoka, & Morimoto, ) and systems to support the development of porcine oocytes were described as more advanced than those of other large animal species (Telfer et al, ).…”

Age-associated changes in granulosa cells and follicular fluid in cows

“…3: Effects of modifying culture conditions for the proliferation of granulosa cells on the energy status of oocytes grown in vitro . OGCs of EAFs were cultured on acrylamide gels, which enhanced granulosa cell proliferation; after which, ATP and lipid contents as well as the acetylation levels of proteins and histones were compared to those cultured without acrylamide gels [ 57 ]. ): 1) Does artificially increasing the number of granulosa cells result in the high-energy status of oocytes grown in vitro ?…”

Addition of granulosa cells collected from differential follicle stages supports development of oocytes derived from porcine early antral follicles

“…Many factors have been reported to affect lipid content in oocytes; for example, higher lipid content in culture medium increased lipid content in oocyte and GCs . In addition, a greater number of GCs increased lipid content of oocytes grown in vitro, suggesting that high energy conditions are associated with lipid accumulation in oocytes. In the present study, we did not find any difference in GC numbers between GC‐added OGCs and natural OGCs.…”