scholarly journals Phase separation during mouse early embryonic development and underlying genetic and epigenetic correlations

2019 ◽  
Author(s):  
Hui Quan ◽  
Sirui Liu ◽  
Yu Zhang ◽  
Wei Xie ◽  
Yi Qin Gao

ABSTRACTChromatin undergoes drastic organization and epigenetic reprogramming during embryonic development in mammals. However, the relationship among global structural change, epigenetic reprogramming, and functional implementation is largely unknown. Based on the analysis of latest published Hi-C data of post-implantation stages, we present a consistent view of the chromatin structural change and the corresponding sequence dependence. Two types of sequentially, genetically and transcriptionally distinct domains, forests and prairies, show systematic and overall increase of spatial segregation during embryonic development, but with notable mixing occurring at two stages, ZGA and implantation. The segregation level change largely coincides with the change of genetic and epigenetic properties. Detailed gene functions in specific phase-changing domains during implantation were analyzed, based on which a possible mechanism of functional realization during implantation was proposed. Interestingly, body temperature changes coincide with the change in chromatin segregation, implying that temperature is a possible factor influencing global chromatin structure.

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2521
Author(s):  
Hui Quan ◽  
Hao Tian ◽  
Sirui Liu ◽  
Yue Xue ◽  
Yu Zhang ◽  
...  

Chromatin undergoes drastic structural organization and epigenetic reprogramming during embryonic development. We present here a consistent view of the chromatin structural change, epigenetic reprogramming, and the corresponding sequence-dependence in both mouse and human embryo development. The two types of domains, identified earlier as forests (CGI-rich domains) and prairies (CGI-poor domains) based on the uneven distribution of CGI in the genome, become spatially segregated during embryonic development, with the exception of zygotic genome activation (ZGA) and implantation, at which point significant domain mixing occurs. Structural segregation largely coincides with DNA methylation and gene expression changes. Genes located in mixed prairie domains show proliferation and ectoderm differentiation-related function in ZGA and implantation, respectively. The chromatin of the ectoderm shows the weakest and the endoderm the strongest domain segregation in germ layers. This chromatin structure difference between different germ layers generally enlarges upon further differentiation. The systematic chromatin structure establishment and its sequence-based segregation strongly suggest the DNA sequence as a possible driving force for the establishment of chromatin 3D structures that profoundly affect the expression profile. Other possible factors correlated with or influencing chromatin structures, including transcription, the germ layers, and the cell cycle, are discussed for an understanding of concerted chromatin structure and epigenetic changes in development.


2021 ◽  
Author(s):  
Hui Quan ◽  
Hao Tian ◽  
Sirui Liu ◽  
Yue Xue ◽  
Yu Zhang ◽  
...  

AbstractChromatin undergoes drastic structural organization and epigenetic reprogramming during embryonic development. We present here a consistent view of the chromatin structural change, epigenetic reprogramming and the corresponding sequence dependence in both mouse and human embryo development. The two types of domains, identified earlier as forests and prairies, become spatially segregated during embryonic development, with the exception of zygotic genome activation (ZGA) and implantation, at which notable domain mixing occurs. Structural segregation largely coincides with DNA methylation and gene expression changes. Genes located in mixed prairie domains show proliferation and ectoderm differentiation-related function in ZGA and implantation, respectively. Chromatin of ectoderm shows the weakest and endoderm the strongest domain segregation in germ layers. This chromatin structure difference between different germ layers generally enlarges in further differentiation. The systematic chromatin structure establishment and its sequence-based segregation strongly suggest DNA sequence as a possible driving force for the establishment of chromatin 3D structures which affect profoundly the expression profile. Other possible factors correlated with/influencing chromatin structures, including temperature, germ layers, and cell cycle, are discussed for an understanding of concerted chromatin structure and epigenetic changes in development.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3464
Author(s):  
Xuan Zou ◽  
Jingyuan Zhou ◽  
Xianwen Ran ◽  
Yiting Wu ◽  
Ping Liu ◽  
...  

Recent studies have shown that the energy release capacity of Polytetrafluoroethylene (PTFE)/Al with Si, and CuO, respectively, is higher than that of PTFE/Al. PTFE/Al/Si/CuO reactive materials with four proportions of PTFE/Si were designed by the molding–sintering process to study the influence of different PTFE/Si mass ratios on energy release. A drop hammer was selected for igniting the specimens, and the high-speed camera and spectrometer systems were used to record the energy release process and the flame spectrum, respectively. The ignition height of the reactive material was obtained by fitting the relationship between the flame duration and the drop height. It was found that the ignition height of PTFE/Al/Si/CuO containing 20% PTFE/Si is 48.27 cm, which is the lowest compared to the ignition height of other Si/PTFE ratios of PTFE/Al/Si/CuO; the flame temperature was calculated from the flame spectrum. It was found that flame temperature changes little for the same reactive material at different drop heights. Compared with the flame temperature of PTFE/Al/Si/CuO with four mass ratios, it was found that the flame temperature of PTFE/Al/Si/CuO with 20% PTFE/Si is the highest, which is 2589 K. The results show that PTFE/Al/Si/CuO containing 20% PTFE/Si is easier to be ignited and has a stronger temperature destruction effect.


2011 ◽  
Vol 10 (2) ◽  
pp. 52-76 ◽  
Author(s):  
Yang Yao

China's export-led growth is rooted in China's double transition of demographic transition and structural change from industrialization. Accession to the WTO has allowed China to fully integrate into the world system and capture the gains of its comparative advantage in abundant labor supply. Structural change has a dampening effect on the Balassa–Samuelson effect so as to sustain China's competiveness in the world market. The double transition will take 10 to 15 years to finish; in this time period, China will likely continue its fast export-led growth. Along the way, export-led growth has also created serious structural imbalances highlighted by underutilized savings, slow growth of residential income and domestic consumption, and a heavy reliance on investment. This linkage requires new thinking when global imbalances are to be tackled.


1989 ◽  
Vol 69 (3) ◽  
pp. 749-761 ◽  
Author(s):  
ULRICH HERTER ◽  
JOSEPH S. BURRIS

Mechanical drying has frequently caused injury in corn seed. Changes in seed moisture, temperature, and quality were determined for inbred lines A632, B73 and Mo17 to define the relationship between these variables. Ears harvested at ca. 48 and 38% seed moisture could be dried at 50 °C for 4–15 h and 18–24 h, respectively, before germination started to decline linearly with prolonged 50 °C drying. Drying time at 50 °C, seed moisture, or embryo moisture after 50 °C drying could be used equally well for prediction of seed quality. Seedling dry weights often declined even when seed was dried for only a few hours at 50 °C. Temperature measurements within seeds indicated that evaporation cooled the seed no more than 5 °C. Drying susceptibility of seed parents varied greatly between years.Key words: Moisture, temperature changes, seed corn, drying


2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Sarah Wyck ◽  
Carolina Herrera ◽  
Cristina E. Requena ◽  
Lilli Bittner ◽  
Petra Hajkova ◽  
...  

2014 ◽  
Vol 18 (1) ◽  
pp. 22-35 ◽  
Author(s):  
Domenico Celenza ◽  
Fabrizio Rossi

Purpose – The aim of this paper is to investigate the relationship between corporate performance and Value Added Intellectual Coefficient (VAICTM) on the one hand, and the relationship between the variations in market value and the variations in VAIC on the other hand. Design/methodology/approach – Starting from the VAIC model, 23 Italian listed companies were examined with the aim of investigating the relationship between VAIC and the performance of the firms in the sample. The analysis was divided into two stages. In the first stage, eight models of linear regression were estimated to verify the presence of a positive and statistically significant relationship between M/BV and VAIC and between accounting performance indicators (ROE, ROI, ROS) and the VAIC. In the second stage, six other models were tested, considering as an independent variable the variations in VAIC and the variations in profitability indicators. Findings – The outcomes of the application stress the importance of VAIC in the explanation of the variations in MV and its role as “additional coefficient” in the analysis of equity performance. Originality/value – This methodology highlights some very interesting aspects. In particular, whereas the relationship between M/BV and VAIC and between profitability indicators (ROI, ROE, ROS) and VAIC is statistically insignificant, the subsequent analysis highlights the importance of VAIC as a variable capable of increasing the explanatory power of the regression in a cross-sectional perspective.


2001 ◽  
Vol 47 (156) ◽  
pp. 147-151 ◽  
Author(s):  
He Yuanqing ◽  
Wilfred H. Theakstone ◽  
Yao Tandong ◽  
Shi Yafeng

AbstractStratigraphic variations of oxygen isotopes in the snow which accumulates during the winter at the Norwegian glacier Austre Okstindbreen are not entirely eliminated after 1–2 months of ablation in the following summer. The relationship between regional temperature changes and δ18O values in the snowpack is affected by many natural factors, but 1989/90 winter air temperatures were reflected in the snow which remained on Austre Okstindbreen at 1350 m a.s.l. in July 1990. There were many variations of δ18O values in the 4.1m of snow above the 1989 summer surface, but variations in the underlying firn were relatively small. Meltwater percolation modifies the initial variations of δ18O values in the snowpack. At a site below the mean equilibrium-line altitude on Austre Okstindbreen, increased isotopic homogenization within a 10 day period in July accompanied an increase of the mean δ18O value. Although the isotopic record at a temperate glacier is likely to be influenced by more factors than is that at polar glaciers, it can provide an estimate of the approximate trend of local temperature variations.


2019 ◽  
Author(s):  
Hua Xu ◽  
Xin Wang ◽  
Zhikai Wang ◽  
Jianhui Li ◽  
Zhiming Xu ◽  
...  

Abstract Background: MicroRNAs (miRNAs) are a class of noncoding small RNAs that play important roles in many physiological processes by regulating gene expression. Previous studies have shown that the expression levels of total miRNAs increase during mouse embryonic development, and some miRNAs control the regulatory network in development progression. However, few studies have focused on the effects of miRNAs on early human embryonic development. The relationship between miRNAs and early human embryogenesis is still unknown. Results:In this study, RNA-seq data collected from sperm samples from 102 patients with a normal sperm index but treated with assisted reproductive technology (ART) were analyzed for the relationships between differentially expressed small RNAs and the fertilization rate (FR), blastocyst rate and high-quality embryo rate (HQER). The sperm samples with high hsa-mir-191 expression had a higher FR, effective embryo rate (EER) and HQER. hsa-mir-191 was used as a single indicator to predict the HQER. The receiver operating characteristic (ROC) curve had an area under the ROC curve (AUC) of 0.686. We also found that hsa-mir-191 expression is correlated with an abnormal sperm rate (cor = 0.29, p< 0.01). We also evaluated the relationship between hsa-mir-34c and early human embryo development in these 102 sperm samples and obtained negative results. Conclusions: These findings suggest that high hsa-mir-191-5p expression in sperm is associated with early human embryonic quality and that hsa-mir-191-5p could be used as a potential marker to screen high-quality sperm to improve the success rates of in vitro fertilization (IVF).


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