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The mammalian target of rapamycin, mTOR, is a serine-threonine protein kinase downstream of the phosphatidylinositol 3-kinase (PI3K)-AKT axis. The pathway can regulate cell growth, proliferation, and survival by activating ribosomal kinases. Recent studies have implicated the mTOR signaling pathway in ovarian neoplasms, polycystic ovary syndrome (PCOS) and premature ovarian failure (POF). Preclinical investigations have demonstrated that the PI3K/AKT/mTOR pathway is frequently activated in the control of various ovarian functions. mTOR allows cancer cells to escape the normal biochemical system and regulates the balance between apoptosis and survival. Some recent studies have suggested that involvement of the mTOR signaling system is an important pathophysiological basis of PCOS. Overexpression of the mTOR pathway can impair the interaction of cumulus cells, lead to insulin resistance, and affect the growth of follicles directly. The roles of mTOR signaling in follicular development have been extensively studied in recent years; abnormalities in this process lead to a series of pathologies such as POF and infertility. To improve understanding of the role of the mTOR signaling pathway in the pathogenesis and development of ovarian diseases, here we review the roles of mTOR signaling in such diseases and discuss the corresponding therapeutic strategies that target this pathway. Clin. Anat. 31:891-898, 2018. © 2018 Wiley Periodicals, Inc.

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Purpose By comparing the chromosomal constitution among the arrested cleavage-stage embryos, blastocysts and human embryonic stem cells (hESCs) which are all derived from monopronuclear (1PN) zygotes, it is aimed to determine whether chromosomally normal embryos can be reliably selected by blastocyst culture. Methods After 1PN zygotes are sequentially cultured for 5 days, the blastocysts and arrested cleavage-stage embryos were analyzed by fluorescence in situ hybridization (FISH) with probes for chromosomes 18, X and Y; G-banding analysis was adopted to analyze the karyotype of 1PN hESCs.Results The diploid rate of blastocysts was 74.6%, which was significantly (P<0.001) higher than that of arrested cleavage-stage embryos (31.6%), and the diploid rate of hESCs was 97.0%, which was significantly (P < 0.01) higher than that of blastocysts; the haploid embryos were excluded by blastocyst culture; nevertheless, there still existed such chromosomal abnormalities as mosaic and monosomic in blastocysts and trisomy in hESCs. Conclusions Blastocyst culture is an effective method to select against chromosomal abnormalities, especially the haploids in 1PN embryos; however, development to the blastocyst stage is not a reliable marker for mosaicism or aneuploidy.

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