Neonatal exposure to xenoestrogens impairs the ovarian response to gonadotropin treatment in lambs

Bisphenol A (BPA) and diethylstilbestrol (DES) are xenoestrogens which have been associated with altered effects on reproduction. We hypothesized that neonatal xenoestrogen exposure affects the ovarian functionality in lambs. Thus, we evaluated the ovarian response to exogenous ovine Follicle Stimulating Hormone (oFSH) administered from postnatal day 30 (PND30) to PND32 in female lambs previously exposed to low doses of DES or BPA (BPA50: 50 μg/kg.day, BPA0.5: 0.5 μg/kg.day) from PND1 to PND14. We determined: a) follicular growth, b) circulating levels of E2, c) steroid receptors (ERA, ERB, AR) and atresia, d) mRNA expression levels of the ovarian bone morphogenetic protein (BMPs) system (BMP6, BMP15, BMP receptor type 1B, GDF9) and FSH receptor (FSHR). Lambs neonatally exposed to DES or BPA showed an impaired ovarian response to oFSH with a lower number of follicles ≥2 mm together with a lower number of atretic follicles and no increase in E2 serum levels in response to oFSH treatment. In addition, AR induction by oFSH was disrupted in granulosa and theca cells of lambs exposed to DES or BPA. An increase in GDF9 mRNA expression levels was observed in oFSH-primed lambs previously treated with DES or BPA50. In contrast, a decrease in BMPR1B was observed in BPA0.5-postnatally exposed lambs. The modifications in AR, GDF9 and BMPR1B may be associated with the altered ovarian function due to neonatal xenoestrogen exposure in response to an exogenous gonadotropin stimulus. These alterations may be the pathophysiological basis of subfertility syndrome in adulthood.Fil: Rivera, Oscar E.. Universidad Nacional de Lomas de Zamora. Facultad de Ciencias Agrarias; ArgentinaFil: Varayoud, Jorgelina Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Rodriguez, Horacio Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Santamaría, Clarisa Guillermina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Bosquiazzo, Veronica Lis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Osti, Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Belmonte, Norberto Miguel. Universidad Nacional de Lomas de Zamora. Facultad de Ciencias Agrarias; ArgentinaFil: Muñoz de Toro, Monica Milagros. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Luque, Enrique Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; Argentin

Effects of perinatal exposure to endocrine disruptors on ovarian development and female fertility

Fil: Santamaría, Clarisa Guillermina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina.En esta tesis doctoral nuestra hipótesis general postula que la exposición a químicos clasificados como xenoestrógenos en períodos hormono-sensibles del desarrollo induce alteraciones en procesos críticos del desarrollo normal de las gónadas y el tracto reproductor femenino, impactando negativamente en la capacidad reproductiva en la vida adulta. Entre los xenoestrógenos más utilizados estudiamos al Bisfenol A (BPA) y al Dietilestilbestrol (DES). En el Capítulo 1: Disfunciones ováricas en ratas adultas nacidas de madres tratadas con bajas dosis de BPA por vía oral, nuestros resultados muestran que el BPA es capaz de afectar los estadíos tempranos del desarrollo ovárico con consecuencias en la edad adulta. En el Capítulo 2: Efectos del BPA sobre la respuesta ovárica al tratamiento con gonadotrofinas exógenas en ratas, demostramos que la exposición perinatal a BPA, condiciona la capacidad de respuesta del ovario a un tratamiento con gonadotrofinas exógenas. En el Capítulo 3: Acción del BPA en el ensamblado folicular en cultivos de ovarios enteros, demostramos que tanto en ratas como en ratones OCT4-GFP, el BPA es capaz de impactar de forma directa sobre el ensamblado folicular. Finalmente en el Capítulo 4: demostramos que la exposición neonatal a xenoestrógenos altera la respuesta ovárica al tratamiento con gonadotrofina en corderas. Los resultados detallados en esta tesis doctoral fundamentan la preocupación mundial por la creciente exposición a estrógenos ambientales, y demuestran que el desarrollo folicular y la síntesis esteroidogénica ováricas son un blanco de acción constante de los mismos.In this doctoral thesis our general hypothesis postulates that exposure to chemicals classified as xenoestrogens in hormone-sensitive developmental periods induces alterations in critical processes of the normal development of the gonads and the female reproductive tract, negatively impacting reproductive capacity in adulthood. We studied two of the most used xenoestrogens, Bisphenol A (BPA) and Diethylstilbestrol (DES). In Chapter 1: Ovarian dysfunctions in adult rats born to mothers treated with low doses of oral BPA, our results show that BPA is able to affect the early stages of ovarian development with consequences in adulthood. In Chapter 2: Effects of BPA on ovarian response to treatment with exogenous gonadotrophins in rats, we demonstrated that perinatal exposure to BPA, conditions the ovary's responsiveness to treatment with exogenous gonadotrophins. In Chapter 3: Action of BPA on follicular assembly in whole ovary cultures, we demonstrated that in both rats and OCT4-GFP mice, BPA is able to directly impact the follicular assembly. Finally in Chapter 4: we demonstrate that neonatal exposure to xenoestrogens alters the ovarian response to treatment with gonadotrophin in lambs. The results detailed in this doctoral thesis are based on the worldwide concern about the increasing exposure to environmental estrogens, and demonstrate that the follicular development and steroidogenic ovarian synthesis are a constant target of the xenoestrogens.Consejo Nacional de Investigaciones Científicas y Técnica

Development of a quantitative immuno-polymerase chain reaction assay to detect and quantify low levels of human thyroid stimulating hormone

In the present study, we developed both a conventional enzyme-linked immunosorbent assay (ELISA) and a highly sensitive immuno-polymerase chain reaction (IPCR) assay specific for detection of human thyroid stimulating hormone (hTSH). Several anti-hTSH monoclonal antibodies (MAbs) were generated using hybridoma technology. Two pairs of MAbs (B-4 and B-9) were rationally selected and the optimal assay conditions of sandwich ELISAs were established. The ELISA prototypes were evaluated with standards calibrated with WHO 2nd International Reference Preparation for hTSH and in comparison with a commercial ELISA Kit. Although the limit of detection (LOD) was 0.1 μIU/ml in all cases, B-9-ELISA showed an analytical performance similar to commercial ELISA Kit. Therefore, we selected the B-9 ELISA to develop a hTSH-IPCR assay applying an “Universal-IPCR” format in standard PCR tubes without pretreatment. The signal amplification was achieved through the interaction between the biotinylated detection MAb and mono-biotinylated DNA probe pre-self-assembled with neutravidin. The hTSH-IPCR assay showed a significant increase in terms of the slope definition of sensitivity in low levels range. Our results support the potential of IPCR technique for being applied in clinical diagnosis of thyroid states.Fil: Abud, Julián Elías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Santamaría, Clarisa Guillermina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Luque, Enrique Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Rodriguez, Horacio Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; Argentin

Methodological aspects of Universal immuno-PCR on standard tubes

One of the most used formats in inmuno-polymerase chain reaction (IPCR) is known as "Universal" IPCR (signal-generating complexes is based on conjugates of biotinylated DNA, biotinylated IgG and avidin). In the present study, we evaluated the utility of using mono- and bi-biotinylated DNA probes, pre-self-assembled DNA-neutravidin complex, blocking step and glutaraldehyde pretreatment of standard PCR tubes to improve the analytical performance of the hTSH-IPCR assay. The use of pre-self-assembled mono-biotinylated DNA-neutravidin complex enhances both the sensitivity and the reproducibility of the hTSH-IPCR assay, even without blocking step: hTSH-IPCR assay showed an improved limit of detection (LOD: 0.01 μIU/ml), calibration sensitivity (SEN: 2.4) and analytic sensitivity (γ: 9 μIU/ml −1 ) in comparison with both a self-made ELISA and a commercial one.Fil: Abud, Julián Elías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Santamaría, Clarisa Guillermina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Oggero Eberhardt, Marcos Rafael. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Cultivos Celulares; ArgentinaFil: Rodriguez, Horacio Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; Argentin

Culturing rat whole ovary for UV filter benzophenone 3 treatment

Here, we described a detailed protocol to establish a newborn rat whole ovary culture, able to study direct effects (independent of hypothalamic-pituitary-gonadal axis) of Endocrine Disrupting Chemicals (EDC), such as Benzophenone 3 (BP-3). This method is useful to understand changes in follicle formation, primordial to primary transition and expression of regulatory molecules linked to these processes as also provides an alternative to animal models. Basic protocols described here are the following:BASIC PROTOCOL 1: RAT OVARIAN SURGERYBASIC PROTOCOL 2: WHOLE ORGAN/OVARIAN CULTUREBASIC PROTOCOL 3: RNA ISOLATION AND QUANTITATIVE REAL TIME-PCRBASIC PROTOCOL 4: HISTOLOGICAL PROCESSING AND STAININGFil: Santamaría, Clarisa Guillermina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Abud, Julián Elías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Luque, Enrique Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Kass, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Rodriguez, Horacio Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; Argentin

Determination of 2-hydroxy-4-methoxybenzophenone in mice serum and human plasma by ultra-high-performance liquid chromatography enhanced by chemometrics

This work presents the development of a strategy for the quantitation of 2-hydroxy-4-methoxybenzophenone (BP-3) in mice serum and human plasma. The instrumental determination only lasts 2 min and is based on ultra-high-performance liquid chromatography (UHPLC) coupled to second-order data modeling with multivariate curve resolution-alternating least-squares (MCR-ALS). Coelution of BP-3 with the matrix components was resolved by exploiting the second-order advantage of multi-way calibration. The validation study led to the following results: linear range from 0.002 to 1.509 μg mL−1; in the case of mice serum samples: recoveries from 95 to 98%, with intra and inter day precision of 2.7 and 5.7, respectively; and in the case of human plasma samples: recoveries from 94 to 99% with intra and inter day precision of 2.3 and 4.6%, respectively. Special emphasis was put on the determination of the LOD and LOQ by utilizing several approaches for their calculation and making focus on the experimental verification of the figures provided by the multivariate methodology. Following the mentioned approach, the LOD and LOQ of the method were estimated as 0.66 and 2.00 ng mL−1, respectively. Eventually, the method was successfully applied to the determination of BP-3 in mice serum.Fil: Teglia, Carla Mariela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral; ArgentinaFil: Santamaría, Clarisa Guillermina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodriguez, Horacio Adolfo. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Culzoni, Maria Julia. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Goicoechea, Hector Casimiro. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Neonatal exposure to bisphenol A reduces the pool of primordial follicles in the rat ovary

We evaluated whether exposure to bisphenol A (BPA) disrupts neonatal follicle development in rats. From postnatal day 1 (PND1) to PND7, pups received corn oil (control), diethylstilbestrol (DES20: 20 μg/kg-d, DES0.2: 0.2 μg/kg-d), or BPA (BPA20: 20. mg/kg-d, BPA0.05: 0.05. mg/kg-d). We examined follicular dynamics, multioocyte follicles (MOFs) incidence, proliferation and apoptosis rates, expression of steroid receptors (ERα, ERβ, PR, AR) and cyclin-dependent kinase inhibitor 1B (p27) in PND8 ovaries. DES20, DES0.2 and BPA20-ovaries showed fewer primordial follicles and increased growing follicles. DES20-ovaries exhibited increased incidence of MOFs. Oocyte survival, AR, PR and apoptosis were not changed. Primordial and recruited follicles from BPA20-ovaries showed higher p27, whereas ERβ and proliferation were both increased in recruited follicles. ERα positive primary follicles increased in BPA 20-ovaries. Results show that BPA reduces the primordial follicle pool by stimulating the neonatal initial recruitment, associated with an increased proliferation rate likely mediated by an estrogenic pathway.Fil: Rodriguez, Horacio Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Departamento de Fisiología. Laboratorio de Endocrinología y Tumores Hormonodependientes; ArgentinaFil: Santambrosio, Noelia. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Departamento de Fisiología. Laboratorio de Endocrinología y Tumores Hormonodependientes; ArgentinaFil: Santamaría, Clarisa Guillermina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Departamento de Fisiología. Laboratorio de Endocrinología y Tumores Hormonodependientes; ArgentinaFil: Muñoz de Toro, Monica Milagros. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Departamento de Fisiología. Laboratorio de Endocrinología y Tumores Hormonodependientes; ArgentinaFil: Luque, Enrique Hugo. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Departamento de Fisiología. Laboratorio de Endocrinología y Tumores Hormonodependientes; Argentin

Exposure to 17alfa-ethynil estradiol during early pregnancy affects fetal development and survival

17α-ethinyl estradiol (EE2) is a synthetic compound widely used in the generation of contraceptive pills. EE2 is present in the urine of women taking contraceptives and its presence has been confirmed at increasing concentrations contaminating rivers all over the world. Because of this cycle, it can entry the human food chain when watering plants. A negative influence of EE2 on fertility and reproductive capacity of wildlife was already suggested. The short-term impact of exposure to contaminating EE2 on pregnancy outcome has not been addressed. Pregnant mice were exposed to either 0.005 μg (concentrations found in water) or 5 μg EE2/kg (contraceptive dose) body weight/day from gestation day 1-7 by oral gavage. Control mice received a 0.1% ethanol solution. High frequency ultrasound imaging was used to follow-up fetal and placental growth in vivo. Doppler measurements were utilized to analyze blood flow parameters in uterine and umbilical arteries. Mice were sacrificed at gd5, 10, and 14. We show that most fetuses of mothers exposed to the high EE2 dose die intrauterine at gd10, with implantation sizes beginning to be smaller already at gd8. Mothers exposed to the low EE2 dose show an impaired remodeling of the spiral arteries, a higher placental weight and pups that are large for gestational age. The insulin-like growth factor system that regulates fetal and placental growth and development is affected by the EE2 treatment. Our results show that a short-term exposure to EE2 during early pregnancy has severe consequences for fetal growth and survival depending on the dose. Exposition to synthetic estrogens affects placenta growth and angiogenesis. These findings urge to the study of mechanisms dysregulated upon environmental exposition to estrogens.Fil: Meyer, N.. Experimental Obstetrics And Gynecology;Fil: Santamaría, Clarisa Guillermina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Muller, J. E.. Experimental Obstetrics And Gynecology;Fil: Schumacher, A.. Experimental Obstetrics And Gynecology;Fil: Rodriguez, Horacio Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Zenclussen, A. C.. Experimental Obstetrics And Gynecology

Ovarian dysfunctions in adult female rat offspring born to mothers perinatally exposed to low doses of bisphenol A

The study of oral exposure to the environmental estrogen bisphenol A (BPA) during the perinatal periodand its effects on ovarian functionality in adulthood has generated special interest. Thus, our objectivewas to investigate ovarian folliculogenesis and steroidogenesis in adult female rat offspring born tomothers exposed to low doses of BPA (BPA50: 50 mg/kg day; BPA0.5: 0.5 mg/kg day) by the oral routeduring gestation and breastfeeding. Ovaries from both BPA-treated groups showed reduced primordialfollicle recruitment and a greater number of corpora lutea, indicating an increased number of ovulatedoocytes, coupled with higher levels of mRNA expression of 3b-hydroxysteroid dehydrogenase and serumprogesterone. BPA50-treated animals had lower expression of androgen receptor (AR) at different stagesof the growing follicle population. BPA0.5-treated rats evidenced an imbalance of AR expression betweenprimordial/primary follicles, with higher mRNA-follicle-stimulating hormone receptor expression. Theseresults add to the growing evidence that folliculogenesis and steroidogenesis are targets of BPA withinthe ovary.Fil: Santamaría, Clarisa Guillermina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Durando, Milena de Lourdes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Muñoz de Toro, Monica Milagros. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Luque, Enrique Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Rodriguez, Horacio Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; Argentin

The UV filter benzophenone 3, alters early follicular assembly in rat whole ovary cultures

Our goalwas to study the effect of BP3 (benzophenone 3) in the follicular assembly and thepotential involvement of Foxl2 pathway using whole ovary cultures. Ovaries werecollected from Wistar rats at birth, treated in vitro with vehicle (0.01 %DMSO), BP3 (5.8 nM, 276 nM, 576 nM and 876 nM) or ESR2 inhibitor (0.1 nM), andcultured for 7 days. Nest breakdown, follicular assembly and the expression ofseveral regulators of these processes (p27, Foxl2, Sox9, Bmp2, Cyp19 and Fst)were evaluated. In vitro exposure to BP3 (5.8 nM) decreased the population oftotal oocytes, the number of nests per ovary and early primary folliclespopulation. In addition, BP3 (5.8 nM) induced overexpression of Foxl2 mRNAlevels through ESR2 but increased Fst mRNA levels independently from ESR2 orFoxl2. We also observed that the number of p27-positive oocytes was decreasedafter BP3 (5.8 nM). On the other hand, exposure to BP3-276 increased totaloocytes, the number of nests per ovary and decreased primary follicles. Inaddition, BP3-276 induced no changes of Foxl2 mRNA levels through ESR2 but increasedFst mRNA levels independently from ESR2 or Foxl2. In conclusion, our studyclearly shows that exposure to BP3 is to perturb the early events of germ cell developmentas showed here in whole ovary cultures.Fil: Santamaría, Clarisa Guillermina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Abud, Julián Elías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Porporato, Melina Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Meyer, N.. Otto-von-guericke University; AlemaniaFil: Zenclussen, A. C.. Otto-von-guericke University; AlemaniaFil: Kass, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Rodriguez, Horacio Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; Argentin