Yusuke Fukuda

Effects of assisted reproduction technology on placental imprinted gene expression.

We used placental tissue to compare the imprinted gene expression of IGF2, H19, KCNQ1OT1, and CDKN1C of singletons conceived via assisted reproduction technology (ART) with that of spontaneously conceived (SC) singletons. Of 989 singletons examined (ART n = 65; SC n = 924), neonatal weight was significantly lower (P < .001) in the ART group than in the SC group, but placental weight showed no significant difference. Gene expression analyzed by real-time PCR was similar for both groups with appropriate-for-date (AFD) birth weight. H19 expression was suppressed in fetal growth retardation (FGR) cases in the ART and SC groups compared with AFD cases (P < .02 and P < .05, resp.). In contrast, CDKN1C expression was suppressed in FGR cases in the ART group (P < .01), while KCNQ1OT1 expression was hyperexpressed in FGR cases in the SC group (P < .05). As imprinted gene expression patterns differed between the ART and SC groups, we speculate that ART modifies epigenetic status even though the possibilities always exist.

Characterization of S100A11, a suppressive factor of fertilization, in the mouse female reproductive tract

We recently found that Xenopus dicalcin, present in the extracellular egg‐coating envelope, suppresses the efficiency of fertilization in vitro through binding to envelope‐constituent glycoproteins. In the present study, we explored the mouse counterpart of Xenopus dicalcin, specifically its localization in the female reproductive tract and its action on mouse fertilization. Our homology and phylogenetic analyses using known S100 proteins showed that S100A11 is most closely related to Xenopus dicalcin. S100A11 was localized in the cytosol of luteal cells, but not in the follicle, in the mouse ovary, and also in the cytosol of the oviductal epithelial cells. In addition, our quantitative analyses revealed preferential expression of S100A11 in the ampullary region of the oviduct and at the estrus stage during the mouse estrous cycle. In the cumulus cell–oocyte complex dissected from the oviduct following ovulation, S100A11 was present in the plasma membrane of cumulus cells, but not in the zona pellucida, which is comparable with Ca2+‐dependent binding of exogenously applied S100A11 to the plasma membrane of cumulus cells. Pretreatment of the cumulus cell–oocyte complex with recombinant S100A11 substantially reduced the efficiency of in vitro fertilization, but S100A10, the next closest S100 protein to Xenopus dicalcin, had no effect. These results suggested that S100A11 is the mouse counterpart of Xenopus dicalcin, suppresses the fertilization process through its action on cumulus cells, and thereby plays a key role in fertilization success in the mouse. Mol. Reprod. Dev. 78:91–103, 2011.

Ultrasound-guided laparotomic oocyte retrieval during surgery for fertility preservation in a case of tumor recurrence after a unilateral salpingo-oophorectomy

A 28 year old unmarried woman underwent a unilateral salpingo‐oophorectomy and was suspected of having a malignant tumor in the remaining ovary. After consultation with the patient and her family, it was decided to cryopreserve the unfertilized oocytes. In order to reduce the risk of puncturing or rupturing the tumor when performing the oocyte retrieval from the ovary that was affected by the malignant tumor, it was chosen to use direct laparotomic oocyte retrieval during surgery, instead of conventional transvaginal retrieval. In order to further reduce the risk of tumor rupture, an ultrasound was used in the laparotomy field to precisely puncture only the follicle and thus avoid the tumor. A total of 11 oocytes was retrieved and 10 of them were cryopreserved in the MII phase.

Possibility of Clinical Application of Preimplantation Genetic Screening Following Blastomere Biopsy in Infertility Treatments

Abstract: Preimplantation diagnosis (PGD) has been performed for sex-linked inherited diseases since 1990, and it has also been utilised in Japan. In other countries, Preimplantation Genetic Screening (PGS) has been introduced to reduce pregnancies with aneuploidies. It is useful for diagnosing inherited diseases and reciprocal translocation of early embryos. However, its indication and effectiveness for cases of habitual abortion, advanced maternal age, and repetitive reproductive failure should continue to be a matter of concern.