An integrated chromatin accessibility and transcriptome landscape of human pre-implantation embryos

Early human embryonic development involves extensive changes in chromatin structure and transcriptional activity. Here the authors present LiCAT-seq, a method enabling simultaneous profiling of chromatin accessibility and gene expression with ultra-low input of cells and map chromatin accessibility and transcriptome landscapes for human pre-implantation embryos

Plant Phenotypic Traits Eventually Shape Its Microbiota: A Common Garden Test

Plant genotype drives the development of plant phenotypes and the assembly of plant microbiota. The potential influence of the plant phenotypic characters on its microbiota is not well characterized and the co-occurrence interrelations for specific microbial taxa and plant phenotypic characters are poorly understood. We established a common garden experiment, which quantifies prokaryotic and fungal communities in the phyllosphere and rhizosphere of six spruce (Picea spp.) tree species, through Illumina amplicon sequencing. We tested for relationships between bacterial/archaeal and fungal communities and for the phenotypic characters of their plant hosts. Host phenotypic characters including leaf length, leaf water content, leaf water storage capacity, leaf dry mass per area, leaf nitrogen content, leaf phosphorous content, leaf potassium content, leaf δ13C values, stomatal conductance, net photosynthetic rate, intercellular carbon dioxide concentration, and transpiration rate were significantly correlated with the diversity and composition of the bacterial/archaeal and fungal communities. These correlations between plant microbiota and suites of host plant phenotypic characters suggest that plant genotype shape its microbiota by driving the development of plant phenotypes. This will advance our understanding of plant-microbe associations and the drivers of variation in plant and ecosystem function

Ferroelectricity driven by magnetism in quasi-one-dimensional Ba9Fe3Se15

The spin-induced ferroelectricity in quasi-1D spin chain system is little known, which could be fundamentally different from those in three-dimensional (3D) system. Here, we report the ferroelectricity driven by a tilted screw spin order and its exotic dynamic in the spin-chain compound Ba9Fe3Se15. It is found that the spin-induced polarization has already occurred and exhibits magnetoelectric coupling behavior far above the long-range spin order (LRSO) at TN = 14 K. The polarized entities grow and their dynamic responses slow down gradually with decreasing temperature and permeate the whole lattice to form 3D ferroelectricity at TN. Our results reveal that the short-range spin orders (SRSOs) in the decoupled chains play a key role for the exotic dynamic in this dimension reduced system. Ba9Fe3Se15 is the only example so far which exhibits electric polarization above LRSO temperature because of the formation of SRSOs

A trehalose biosynthetic enzyme doubles as an osmotic stress sensor to regulate bacterial morphogenesis

The dissacharide trehalose is an important intracellular osmoprotectant and the OtsA/B pathway is the principal pathway for trehalose biosynthesis in a wide range of bacterial species. Scaffolding proteins and other cytoskeletal elements play an essential role in morphogenetic processes in bacteria. Here we describe how OtsA, in addition to its role in trehalose biosynthesis, functions as an osmotic stress sensor to regulate cell morphology in Arthrobacter strain A3. In response to osmotic stress, this and other Arthrobacter species undergo a transition from bacillary to myceloid growth. An otsA null mutant exhibits constitutive myceloid growth. Osmotic stress leads to a depletion of trehalose-6-phosphate, the product of the OtsA enzyme, and experimental depletion of this metabolite also leads to constitutive myceloid growth independent of OtsA function. In vitro analyses indicate that OtsA can self-assemble into protein networks, promoted by trehalose-6-phosphate, a property that is not shared by the equivalent enzyme from E. coli, despite the latter's enzymatic activity when expressed in Arthrobacter. This, and the localization of the protein in non-stressed cells at the mid-cell and poles, indicates that OtsA from Arthrobacter likely functions as a cytoskeletal element regulating cell morphology. Recruiting a biosynthetic enzyme for this morphogenetic function represents an intriguing adaptation in bacteria that can survive in extreme environments

Clinical outcomes of multifetal pregnancy reduction in trichorionic and dichorionic triplet pregnancies: A retrospective observational study

Objective: To observe the pregnancy and perinatal outcomes of trichorionic triplet (TCT) and dichorionic triplet (DCT) pregnancies with or without multifetal pregnancy reduction (MFPR). Materials and methods: This was a retrospective study of 732 TCT and 118 DCT pregnancies after IVF/ICSI cycles between October 1999 and May 2014 at the Reproductive & Genetic Hospital of CITIC-Xiangya. The TCT and DCT groups were subdivided into three subgroups: MFPR to single fetus group, MFPR to twins group and expectant group. Pregnancy and perinatal outcomes were compared between different subgroups. Results: The resulting subgroups were TCT-Expectant (n = 40), TCT to twin (n = 610), TCT to single (n = 22), DCT-Expectant (n = 17), DCT to twin (n = 50), and DCT to single (n = 22). The groups with MFPR had the better pregnancy and perinatal outcomes. Meanwhile, the significantly higher abortion rates but lower live birth and take home baby rates were found in TCT-Expectant group and DCT-Expectant group (all P < 0.05). Besides, the abortion rate of DCT-Expectant group was much higher than TCT-Expectant group (41% verse 15%, P = 0.032). As for the perinatal outcomes, retaining single fetus group showed the advantage of higher birth weight, and elder gestational age in both DCT and TCT pregnancies (all P < 0.05). Conclusion: For DCT and TCT pregnancies, MFPR application could reduce the miscarriage rate, while improving live birth and take home baby rates compared to the expectant groups. Especially, when reduced to a single fetus, MFPR could provide the better perinatal outcomes. Keywords: Trichorionic triplet pregnancies, Dichorionic triplet pregnancies, MFPR, Pregnancy outcomes, Perinatal outcome

The complete genome sequence of the cold adapted crude-oil degrader: Pedobacter steynii DX4

Abstract Pedobacter steynii DX4 was isolated from the soil of Tibetan Plateau and it can use crude oil as sole carbon and energy source at 15 °C. The genome of Pedobacter steynii DX4 has been sequenced and served as basis for analysis its metabolic mechanism. It is the first genome of crude oil degrading strain in Pedobacter genus. The 6.58 Mb genome has an average G + C content of 41.31% and encodes 5464 genes. In addition, annotation revealed that Pedobacter steynii DX4 has cold shock proteins, abundant response regulators for cell motility, and enzymes involved in energy conversion and fatty acid metabolism. The genomic characteristics could provide information for further study of oil-degrading microbes for recovery of crude oil polluted environment