Cell proliferation and apoptosis in the fetal and neonatal ovary of guinea pigs

Abstract

ABSTRACT. The guinea pig is an excellent animal model for studying reproductive biology of adult humans and most domestic animals. Yet, whether this animal might serve as a good model for embryonic stage investigations and determinations of signals affecting or directing ovary development remains unknown. These questions were addressed by examining morphological evolution and the expression of biomarkers of cell proliferation and apoptosis in the ovaries of fetal and neonatal guinea pigs in the present study. Embryonic and neonatal guinea pigs at 30, 40, 50, 60, and 68 days postcoitum (dpc) and at 1 day postpartum (dpp) were evaluated, and the dynamic changes in follicles between 30 dpc and 1 dpp were observed. Results also showed that a critical period of follicular development in guinea pig embryos occurred at 40 to 50 dpc. Moreover, the proliferating-cell nuclear antigen, a cell proliferation marker, immunohistochemically stained healthy follicles, while caspase-3, an apoptosis marker, was mainly observed in atretic follicles. Together, these results demonstrate that cell proliferation and apoptosis contribute to follicular formation, development, and atresia in fetal and neonatal guinea pig ovaries. Furthermore, this study Cell proliferation and apoptosis in the ovary of guinea pigs confirmed that the guinea pig is also an excellent animal model for studying reproductive biology in human and domestic animal embryos.

Expression characteristics of MMP-2 and MMP-9 in guinea pig ovaries during the estrous cycle

“…The ovary follicular period of guinea pigs is very similar to that of humans (van Kan et al, 2009), and they are therefore very good animal models for research on human propagation (Kulduk et al, 2014;Sun et al, 2014).…”

Induction of follicular luteinization by equine chorionic gonadotropin in cyclic guinea pigs

“…It was confirmed that a CL-like structure has a significantly lower number of luteinized cells and higher proportion of apoptotic luteinized cells. Cell differentiation and proliferation contribute to follicular formation (Sun et al, 2014). However, the source of differentiated cells is unclear: they may rapidly differentiate from basal membrane cells after apoptosis of granulosa cells, or they may differentiate and proliferate from theca and granulosa cells.…”

“…Guinea pigs are a more reliable reproductive model as compared with mice or rats (Silva et al, 1998;Shi et al, 1999;Kulduk et al, 2014;Sun et al, 2014), because they share similarities with humans and large domestic animals in estrous cycles and prolonged pregnancy (van Kan et al, 2009). Guinea pigs, only ovulate a few oocytes (3.6±0.1) in one typical estrous cycle (Suzuki et al, 1993), and the majority of follicles are lost by atresia (Hermreck and Greenwald, 1964) in the four continuous stages (Wang et al, 2010b).…”

Effects of Echinomycin on Follicular Development in the Ovary of Postnatal Rats

“…At present, the proliferation of granulosa cells has been believed as a vital regulatory factor during the development of ovarian follicles and proliferation cell nuclear antigen (PCNA) was widely used as cell proliferation marker in many lectures [5]. Therefore, the present study used a HIF1alpha small-molecule inhibitor echinomycin (Ech) and a follicular development model of postnatal rats to investigate the contribution of HIF-1alpha to ovarian follicular development through examining the changes of HIF-1alpha and PCNA during the follicular development based on the follicular development characteristics of the model animals in order to further understanding the regulatory mechanism of the follicular development in mammalian ovary.…”