BackgroundRadiation exposure is known to cause accelerated aging and damage to the ovary, but the contribution of indirect versus direct effects is not well understood. We used the Small Animal Radiation Research Platform (SARRP) (Xstrahl) to deliver radiation to precise fields equivalent to clinical practice, allowing us to investigate systemic versus targeted damage in a structure as small as the mouse ovary. The X-ray dose was kept constant at 1 Gy, but the field varied. Mice either received total body irradiation (TBI), radiation targeted to both ovaries (T2), or radiation targeted to one ovary (left) while the contralateral ovary (right) was spared (T1). Sham mice, handled similarly to the other cohorts but not exposed to radiation, served as controls. Two weeks post-exposure, ovaries were harvested and analyzed histologically to identify and count follicles within each ovary.ResultsRadiation significantly reduced primordial follicles in the TBI and T2 cohorts compared to the Sham cohort. There were no significant differences between these two irradiated groups. These findings suggest that at 1 Gy, the extent of damage to the ovary caused by radiation is similar despite the different delivery methods. When investigating the T1 cohort, targeted ovaries showed a significant decrease in primordial and growing follicles compared to non-targeted contralateral ovaries.ConclusionsThese findings demonstrate that the SARRP is an effective strategy for delivering precise ionizing radiation to small organs such as mouse ovaries. Such tools will facilitate identifying the relative risks to ovarian function associated with different radiation fields as well as screening the efficacy of emerging fertoprotective agents.Electronic supplementary materialThe online version of this article (10.1186/s13048-018-0442-8) contains supplementary material, which is available to authorized users.

Objective: Using a baboon model, we determined the changing expression of Retinoic Acid (RA) target genes during the menstrual cycle and during disease progression. This change could explain the cellular response and changes characteristic of endometriosis. In previous studies, we established that endometriosis affects the CRABP2:FABP5 ratio in an in vitro environment, shifting toward apoptosis and differentiation with higher CRABP2, and anti-apoptosis with higher levels of FABP5. Intervention(s): Endometriosis was induced in female baboons with intraperitoneal inoculation of menstrual endometrium ( n = 2–4). Tissue was harvested via endometrectomy during different stages of the menstrual cycle as well at 3, 6, and 12 month timepoints after inoculation with endometriosis. Main outcome measure(s): Real time PCR was used to quantify STRA6 (a gene responsible for retinol uptake), CRABP2 (a gene necessary for apoptotic and anti-apoptotic estrogenic RA effects), and FABP5 (a gene that mediates the anti-apoptotic actions of RA). Results: STRA6 and CRABP2 expression were highest in the proliferative phase and lowest in the late secretory phase. FABP5 expression remained stable throughout the 12 months following the induction of the disease, whereas STRA6 and CRABP2 continued to decrease during the same period. Conclusions: Our study confirms that a shift in the CRABP2:FABP5 ratio has similar in vivo effects as it does in vitro: changing RA expression with disease induction and progression. As CRABP2 may be important in determining cell fate in the endometrium, gene expression changes could contribute to the anti-apoptotic behavior of affected cells. As expression changes more during progression, earlier rather than later treatment becomes more critical in reducing the rate of disease progression.

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In vitro maturation (IVM) is the process whereby oocytes arrested in prophase of meiosis I are stimulated to resume meiosis and progress to metaphase of meiosis II (MII) ex vivo. Here we examined the cytoskeletal morphology of mature MII eggs obtained following IVM. Cumulus oocyte complexes were isolated from antral follicles of hyper-stimulated female mice, and cumulus cells were removed to induce spontaneous oocyte meiotic maturation. Resulting MII eggs were distinguished by extrusion of the fi rst polar body, and cells were fi xed and processed for fl uorescence microscopy with a fl uorescein isothiocyanate-conjugated anti-␣-tubulin antibody, rhodamine-phalloidin, and 4',6-diamidino-2-phenylindole to detect microtubules (green), actin (red), and chromatin (blue), respectively. Cells were imaged using confocal microscopy, and a representative projection of optical sections is shown.The dichotomy of two meiotic products can be seen in this image of an individual MII egg: the collapse of the polar body (arrow) and the creation of the egg. In fact, the most striking feature in this image is the difference in cytoskeletal organization between the egg and polar body. The mature egg possesses characteristic morphology, including: a bipolar spindle positioned in the animal hemisphere of the cell (asterisks), chromosomes tightly aligned on the metaphase plate of the spindle, and an actin-enriched cortical cap overlying the spindle. In contrast to the ordered actin and microtubule cytoskeletons in the egg, the fi rst polar body is fragmenting and exhibits a chaotic cytoskeleton, indicative of a degrading structure. These fi ndings suggest that the data related to egg quality, other than genetic ploidy, extracted from polar bodies should be interpreted with caution