Abstract
The use of gonadotropins to trigger oocyte maturation both
in vivo
and
in vitro
has provided precious and powerful knowledge that has significantly increased our understanding of the ovarian function. Moreover, the efficacy of most assisted reproductive technologies (ART) used in both humans and livestock species relies on gonadotropin input, mainly FSH and LH. Despite the significant progress achieved and the huge impact of gonadotropins, the exact molecular pathways of the two pituitary hormones, FSH and LH, still remain poorly understood. Moreover, these pathways may not be the same when moving from the
in vivo
to the
in vitro
context. This misunderstanding of the intricate synergy between these two hormones leads to a lack of consensus about their use mainly
in vitro
or in ovulation induction schedules
in vivo
. In order to optimize their use, additional work is thus required with a special focus on comparing the
in vitro
versus the
in vivo
effects. In this context, this overview will briefly summarize the downstream gene expression pathways induced by both FSH
in vitro
and LH
in vivo
in the cumulus compartment. Based on recent microarray comparative analysis, we are reporting that
in vitro
FSH stimulation on cumulus cells appears to achieve at least part of the gene expression activity after
in vivo
LH stimulation. We are then proposing that the in vitro FSH-response of cumulus cells have similitudes with the in vivo LH-response.