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Abstract Background Histone acetylation, which is regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs), plays a crucial role in the control of gene expression. HDAC inhibitors (HDACi) have shown potential in cancer therapy; however, the specific roles of HDACs in early embryos remain unclear. Moreover, although some pan-HDACi have been used to maintain cellular undifferentiated states in early embryos, the specific mechanisms underlying their effects remain unknown. Thus, there remains a significant knowledge gap regarding the application of selective HDACi in early embryos. Results To address this gap, we treated early embryos with two selective HDACi (MGCD0103 and T247). Subsequently, we collected and analyzed their transcriptome data at different developmental stages. Our findings unveiled a significant effect of HDACi treatment during the crucial 2-cell stage of zygotes, leading to a delay in embryonic development after T247 and an arrest at 2-cell stage after MGCD0103 administration. Furthermore, we elucidated the regulatory targets underlying this arrested embryonic development, which pinpointed the G2/M phase as the potential period of embryonic development arrest caused by MGCD0103. Moreover, our investigation provided a comprehensive profile of the biological processes that are affected by HDACi, with their main effects being predominantly localized in four aspects of zygotic gene activation (ZGA): RNA splicing, cell cycle regulation, autophagy, and transcription factor regulation. By exploring the transcriptional regulation and epigenetic features of the genes affected by HDACi, we made inferences regarding the potential main pathways via which HDACs affect gene expression in early embryos. Notably, Hdac7 exhibited a distinct response, highlighting its potential as a key player in early embryonic development. Conclusions Our study conducted a comprehensive analysis of the effects of HDACi on early embryonic development at the transcriptional level. The results demonstrated that HDACi significantly affected ZGA in embryos, elucidated the distinct actions of various selective HDACi, and identified specific biological pathways and mechanisms via which these inhibitors modulated early embryonic development.

The lag in quantitative methods and detection techniques for geologic information has resulted in time-consuming and human-experienced geologic analysis in tunnels. Geochemical indicators of rocks can be used to identify adverse geology and to explain the intrinsic causes of damage to normal rocks. This study proposes a method to identify adverse geology by extracting and imaging the indicator elements. The mapping relationship between rock components and geologic bodies is quickly determined by indicator element extraction based on factor analysis, and then the data are gridded for image output. The location and size of the target adverse geology are visually identified through the distribution images of the indicator elements, thus reducing data dimensions and analysis time. A non-destructive, in-situ and fast element detection technique in tunnels was adopted to speed up the process of geology identification. The accuracy of the detection was validated by comparing field and laboratory test results. This study further confirms and refines the previous research, and the results provide references for geological, mining and underground projects.

Abstract Recent excavation of the elephant ivories at the Sanxingdui site of the Shang Dynasty in Sichuan, China brings attention to the burnt features of the ivories. However, burnt ivories cannot be assessed by the same criteria established for burnt bones because of the differences in the ways that the two materials respond to heat. This study examines differences in the phase transition characteristics of ivory and bone, and confirms that the threshold temperature of the alteration in ivories is lower than that in bones. In our analysis, elephant ivories and bovine bones burnt at the temperatures between 200 and 1000 °C in oxidizing or reducing atmosphere are prepared and comparatively investigated by attenuated total reflection Fourier transform infrared spectroscopy. The results show that the transformation from magnesium-substituted hydroxyapatite (Mg-HAp) to magnesium-substituted β-tricalcium phosphate in ivory dentin takes place at the temperature as low as 800 °C, while β-tricalcium phosphate is not observed in bovine bones burnt at 1000 °C or below mainly because of the different magnesium contents. Due to the destruction of Mg-HAp at 800 °C in ivories, cyanamidapatite that could form in bones burnt under reducing atmosphere is absent in burnt ivories. With reference to the experimental burnt ivories, archaeological burnt ivories from the Sanxingdui site can now be clearly determined to be burnt unevenly at temperatures up to around 800 °C. This study may provide further information for archaeological research on ivories from the Sanxingdui site and identification of burnt bioapatite materials in other archaeological findings.

Abstract In multicellular organisms, oocytes and sperm undergo fusion during fertilization and the resulting zygote gives rise to a new individual. The ability of zygotes to produce a fully formed individual from a single cell when placed in a supportive environment is known as totipotency. Given that totipotent cells are the source of all multicellular organisms, a better understanding of totipotency may have a wide-ranging impact on biology. The precise delineation of totipotent cells in mammals has remained elusive, however, although zygotes and single blastomeres of embryos at the two-cell stage have been thought to be the only totipotent cells in mice. We now show that a single blastomere of two- or four-cell mouse embryos can give rise to a fertile adult when placed in a uterus, even though blastomere isolation disturbs the transcriptome of derived embryos. Single blastomeres isolated from embryos at the eight-cell or morula stages and cultured in vitro manifested pronounced defects in the formation of epiblast and primitive endoderm by the inner cell mass and in the development of blastocysts, respectively. Our results thus indicate that totipotency of mouse zygotes extends to single blastomeres of embryos at the four-cell stage.