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Updated: Jul 4, 2026

Whole Ovary Immunofluorescence, Clearing, and Multiphoton Microscopy for Quantitative 3D Analysis of the Developing Ovarian Reserve in Mouse
Published on: September 3, 2021
The developing human ovary: immunohistochemical analysis of germ-cell-specific VASA protein, BCL-2/BAX expression
Mirta S Albamonte1, Miguel A Willis, María I Albamonte
1Departamento de Estudios Biomédicos y Biotecnológicos, Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico, CEBBAD, Universidad Maimónides, Hidalgo 775, C1405BCK Buenos Aires, Argentina.
Background:
Germ cell number during ovarian organogenesis is regulated through programmed cell death. We investigated the expression of germ-cell-specific VASA protein, apoptosis-related proteins BAX and BCL-2 and DNA fragmentation in developing human ovaries from gestation week 12 to term.
Methods:
Human fetal ovaries from 13 women undergoing spontaneous abortion were fixed, paraffin-embedded and processed for immunohistochemistry to analyse temporal and cellular localization of VASA, BCL-2 and BAX, and to detect apoptosis by TUNEL assay.
Results:
VASA showed a differential pattern of expression throughout the differentiation and proliferative phase and prophase I to finally associate with Balbiani's body in primordial and primary follicles. BCL-2 was detected from week 12 to 17 and became undetectable thereafter. Strong BAX signal was detected in oogonia and oocytes from week 12 to term. Low levels (
Conclusions:
VASA was specifically expressed in germ cells and displayed a stage-specific intracellular localization enabling one to follow oogenesis throughout gestation. Apoptosis-inhibiting BCL-2 was associated with the germ cell proliferative phase and prophase I, whereas BAX remained positive throughout gestation. The highest incidence of apoptotic germ cells was coincident with the lack of detectable BCL-2 protein, and when primordial follicle formation became widespread.
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