Molecular evidence that follicle development is accelerated in vitro compared to in vivo

Abstract

In this study, we systematically compared the morphological, functional and molecular characteristics of granulosa cells and oocytes obtained by a three-dimensional model of ovine ovarian follicular growth with those of follicles recovered Preantral follicles of 200 µm diameter were recovered and cultured up to 950 µm over a 20-day period. Compared with follicles, the culture conditions maintained follicle survival, with no difference in the rate of atresia. However, the conditions induced a slight decrease in oocyte growth rate, delayed antrum formation and increased granulosa cell proliferation rate, accompanied by an increase and decrease in and mRNA expression respectively. These changes were associated with advanced granulosa cell differentiation in early antral follicles larger than 400 µm diameter, regardless of the presence or absence of FSH, as indicated by an increase in estradiol secretion, together with decreased AMH secretion and expression, as well as increased expression of, ,, ,, ,, and There was a decrease in the expression of oocyte-specific molecular markers ,, , and compared to that Moreover, a higher percentage of the oocytes recovered from cultured follicles 550 to 950 µm in diameter was able to reach the metaphase II meiosis stage. Overall, this model of ovarian follicle development is characterized by accelerated follicular maturation, associated with improved developmental competence of the oocyte, compared to follicles recovered.

Analysis of expression of genes responsible for regulation of cellular proliferation and migration – microarray approach based on porcine oocyte model

“…In the case of ovarian follicles, it is responsible for the transition from preantral to antral follicle [25]. The Cadoret et al study showed a decreased KIT expression in in vitro culture of ovarian follicle cells, which was explained by the reduced oocyte growth rate in vitro relative to in vivo [26]. In the case of our studies, we showed a decrease in the expression of the KIT gene after IVM which confirms its role of the proliferation and differentiation of oocytes.…”

Interaction between PI3K/AKT and Hippo pathways during in vitro follicular activation and response to fragmentation and chemotherapy exposure using a mouse immature ovary model

“…This redundancy in pathways might explain the moderate impact of 4HC on their expression levels. As folliculogenesis is accelerated in vitro in several species [55], slowing down the activation events by acting on the PI3K pathway appears to be an interesting approach to improving culture yields. Furthermore, it has been reported in mice that mTORC1 inhibition using Everolimus (EVE) prevents follicular activation and protects the ovarian reserve against chemotherapeutic treatment [53].…”

Genome-Wide Association Analyses Highlight the Potential for Different Genetic Mechanisms for Litter Size Among Sheep Breeds

“…In Icelandic sheep, the gene NCOA1 can alter the expression of multiple key genes PBP, AIB3 , and FGFR2 , which are important for aberrant labyrinth morphogenesis of the placenta and embryonic lethality ( Chen et al, 2010 ; Huang et al, 2011 ). In Finnsheep, the five candidate genes INHBB, NF1, FLT1, PTGS2 , and PLCB3 played important roles in the development of folliculogenesis and LH signaling ( Ding et al, 2006 ; Tal et al, 2014 ; De Cesaro et al, 2015 ; Ben Sassi et al, 2016 ; Cadoret et al, 2017 ). For example, the INHBB gene encodes an inhibitor of apoptosis, which regulates porcine ovarian follicular atresia ( Terenina et al, 2017 ).…”