BioOne.org will be down briefly for maintenance on 17 December 2024 between 18:00-22:00 Pacific Time US. We apologize for any inconvenience.
How to translate text using browser tools
23 December 2021 The two-step process of ovarian follicular growth and maturation in mammals can be compared to a fruit ripening where quality depends on the second step
Marc-André Sirard
Author Affiliations +
Abstract

In human in vitro fertilization, the main uncertainty factor impacting on success is oocyte quality, which largely depends on the follicular status at the time of collection. Decades of debate ensued to find the perfect stimulation protocol demonstrated the complexity of the ovarian response to exogenous gonadotropins and the dynamic nature of late folliculogenesis. Although several follicular markers, proteins, RNA from granulosa cells or microRNA, and follicular fluid metabolites have been associated with outcome, the possibility to influence them during stimulation remains elusive. The heterogeneity of the follicle's maturity following control ovarian stimulation is also an important factor to explain average poor oocyte quality still observed today. In this review, the analogy between the apple ripening on the tree and follicular development is presented to focus the attention on a biphasic process: growth and differentiation. The molecular analysis of the progressive follicular differentiation indicates two competing phenomena: growth and differentiation, where a delicate balance must operate from one to the other to ensure proper maturity at ovulation. As long as follicle-stimulating hormone (FSH) stimulates growth, follicles remain green, and it is only when FSH is replaced by luteinizing hormone that the ripening process begins, and “apples” become red. Both fruits, follicles and apples, depend on a perfect timing of events to generate offspring.

Summary Sentence

The importance of the final differentiation process during follicular dominance in relation to the resulting oocyte quality.

Graphical Abstract

img-AEW_230.jpg
© The Author(s) 2021. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com
Marc-André Sirard "The two-step process of ovarian follicular growth and maturation in mammals can be compared to a fruit ripening where quality depends on the second step," Biology of Reproduction 106(2), 230-234, (23 December 2021). https://doi.org/10.1093/biolre/ioab236
Received: 29 September 2021; Accepted: 20 December 2021; Published: 23 December 2021
KEYWORDS
IVF
oocyte quality
Ovarian stimulation
review
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top