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Highlights d A forward genetic screen identifies Zfp281 as a factor for ESto-TS-like conversion d Zfp281 shapes the transcriptome of TS cells and regulates early placental development d Zfp281 interacts with MLL or COMPASS subunits and binds to the promoters of target genes d ZNF281 stabilizes the transcriptome in undifferentiated human TS cells

Establishment of the DNA methylation landscape of mammalian oocytes, mediated by the DNMT3A-DNMT3L complex, is crucial for reproduction and development. In mouse oocytes, high levels of DNA methylation occur exclusively in the transcriptionally active regions, with moderate to low levels of methylation in other regions. Histone H3K36me3 mediates the high levels of methylation in the transcribed regions; however, it is unknown which histone mark guides the methylation in the other regions. Here, we show that, in mouse oocytes, H3K36me2 is highly enriched in the X chromosome and is broadly distributed across all autosomes. Upon H3K36me2 depletion, DNA methylation in moderately methylated regions is selectively affected, and a methylation pattern unique to the X chromosome is switched to an autosome-like pattern. Furthermore, we find that simultaneous depletion of H3K36me2 and H3K36me3 results in global hypomethylation, comparable to that of DNMT3A depletion. Therefore, the two histone marks jointly provide the chromatin platform essential for guiding DNMT3A-dependent DNA methylation in mouse oocytes.

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The Nikon Corporation was able to further improve the surface characteristic of titanium by developing a hydroxyapatite (HA) film on an anodic oxide layer of pure titanium implant (SA treatment). The HA film was composed of an electolytic solution containing Ca and P that underwent anodic oxidation followed by hydrothermal treatment in high pressure steam. This study was conducted to investigate how SA treated implants affect the surrounding bone tissue by analyzing them under an electron probe X-ray microanalyzer (EPMA). HA plasma sprayed pure titanium implants, titanium plasma sprayed pure titanium implants, and SA treated titanium plasma sprayed pure titanium implants were implanted in the mandibles of beagles. After four weeks, the surrounding bone tissues were analyzed according to the distribution of Ca and P by EPMA. The results showed that newly-formed bone had a relatively lower density of Ca and P than the existing bone for all dogs. Titanium plasma sprayed pure titanium implants without SA treatment were found to have less geographical distribution for both Ca and P. The Ca/P ratio showed no significant differences among them, indicating that SA treatment increased the biocompatibility of titanium implants by allowing them to induce more newly-formed bone quantity.

Nucleosome positioning can alter the accessibility of DNA-binding proteins to their cognate DNA elements, and thus its precise control is essential for cell identity and function. Mammalian preimplantation embryos undergo temporal changes in gene expression and cell potency, suggesting the involvement of dynamic epigenetic control during this developmental phase. However, the dynamics of nucleosome organization during early development are poorly understood. In this study, using a low-input MNase-seq method, we show that nucleosome positioning is globally obscure in zygotes but becomes well defined during subsequent development. Down-regulation of the chromatin assembly in embryonic stem cells can partially reverse nucleosome organization into a zygote-like pattern, suggesting a possible link between the chromatin assembly pathway and fuzzy nucleosomes in zygotes. We also reveal that YY1, a zinc finger-containing transcription factor expressed upon zygotic genome activation, regulates the de novo formation of well-positioned nucleosome arrays at the regulatory elements through identifying YY1-binding sites in eight-cell embryos. The YY1-binding regions acquire H3K27ac enrichment around the eight-cell and morula stages, and YY1 depletion impairs the morula-to-blastocyst transition. Thus, our study delineates the remodeling of nucleosome organization and its underlying mechanism during early mouse development.