Med12 regulates ovarian steroidogenesis, uterine development and maternal effects in the mammalian egg.

The transcriptional factor MED12 is part of the essential mediator transcriptional complex that acts as a transcriptional coactivator in all eukaryotes. Missense gain of function mutations in human MED12 are associated with uterine leiomyomas, yet the role of MED12 deficiency in tumorigenesis and reproductive biology has not been fully explored. We generated a Med12 reproductive conditional knockout mouse model to evaluate its role in uterine mesenchyme, granulosa cells, and oocytes. Mice heterozygous for Med12 deficiency in granulosa cells and uterus (Med12fl/+ Amhr2-Cre) were subfertile, while mice homozygous for Med12 deficiency in granulosa cells and uterus (Med12fl/fl Amhr2-Cre) were infertile. Morphological and histological analysis of the Med12fl/fl Amhr2-Cre reproductive tract revealed atrophic uteri and hyperchromatic granulosa cells with disrupted expression of Lhcgr, Esr1, and Esr2. Med12fl/fl Amhr2-Cre mice estrous cycle was disrupted and serum analysis showed blunted rise in estradiol in response to PMSG. Uterine atrophy was partially rescued by exogenous steroid supplementation with dysregulation of Notch1 and Smo expression in steroid supplemented Med12fl/fl Amhr2-Cre uteri, indicating intrinsic uterine defects. Oocyte specific ablation of Med12 caused infertility without disrupting normal folliculogenesis and ovulation, consistent with maternal effects of Med12 in early embryo development. These results show the critical importance of Med12 in reproductive tract development and that Med12 loss of function does not cause tumorigenesis in reproductive tissues. © The Authors 2017. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Citation

Xinye Wang, Priya Mittal, Carlos A Castro, Gabriel Rajkovic, Aleksandar Rajkovic. Med12 regulates ovarian steroidogenesis, uterine development and maternal effects in the mammalian egg. Biology of reproduction. 2017 Nov 08

PMID: 29126187

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