Comparison Between Flat and Round Peaches, Genomic Evidences of Heterozygosity Events

Bud sports occur in many plant species, including fruit trees. Although they are correlated with genetic variance in somatic cells, the mechanisms responsible for bud sports are mostly unknown. In this study, a peach bud sport whose fruit shape was transformed to round from flat was identified by next generation sequencing (NGS), and we provide evidence that a long loss of heterozygosity (LOH) event may be responsible for this alteration in fruit shape. Moreover, compared to the reference genome, we identified 237,476 high quality single nucleotide polymorphisms (SNPs) in the wild-type and bud sport genomes. Using this SNP set, a long LOH event was identified at the distal end of scaffold Pp06 of the bud sport genome. Haplotypes from 155 additional peach accessions were phased, suggesting that the homozygous distal end of scaffold Pp06 of the bud sport was likely derived from only one haplotype of the wild-type flat peach. A genome-wide association study (GWAS) of 127 peach accessions was conducted to associate a SNP found at 26,924,482 bp of scaffold Pp06 to differences in fruit shape. All accessions with round-shaped fruit were found to have an A/A genotype, while those with A/T, or T/T genotypes had flat-shaped fruits. Finally, we also found that 236 peach accessions and 141 Prunus species with round-type fruit were found to have an A/A genotype at this SNP, while 22 flat peach accessions had an A/T genotype. Taken together, our results suggest that genes flanking this A/T polymorphism, and haplotyped carrying the T allele may determine flat fruit shape in this population. Furthermore, the LOH event resulting in the loss of the haplotype carrying the T allele may therefore be responsible for fruit shape alteration in wild-type flat peach

Chromatin Remodeling of Colorectal Cancer Liver Metastasis is Mediated by an HGF‐PU.1‐DPP4 Axis

Colorectal cancer (CRC) metastasizes mainly to the liver, which accounts for the majority of CRC-related deaths. Here it is shown that metastatic cells undergo specific chromatin remodeling in the liver. Hepatic growth factor (HGF) induces phosphorylation of PU.1, a pioneer factor, which in turn binds and opens chromatin regions of downstream effector genes. PU.1 increases histone acetylation at the DPP4 locus. Precise epigenetic silencing by CRISPR/dCas9KRAB or CRISPR/dCas9HDAC revealed that individual PU.1-remodeled regulatory elements collectively modulate DPP4 expression and liver metastasis growth. Genetic silencing or pharmacological inhibition of each factor along this chromatin remodeling axis strongly suppressed liver metastasis. Therefore, microenvironment-induced epimutation is an important mechanism for metastatic tumor cells to grow in their new niche. This study presents a potential strategy to target chromatin remodeling in metastatic cancer and the promise of repurposing drugs to treat metastasis

Draft genome sequence of the mulberry tree Morus notabilis

Human utilization of the mulberry–silkworm interaction started at least 5,000 years ago and greatly influenced world history through the Silk Road. Complementing the silkworm genome sequence, here we describe the genome of a mulberry species Morus notabilis. In the 330-Mb genome assembly, we identify 128 Mb of repetitive sequences and 29,338 genes, 60.8% of which are supported by transcriptome sequencing. Mulberry gene sequences appear to evolve ~3 times faster than other Rosales, perhaps facilitating the species’ spread worldwide. The mulberry tree is among a few eudicots but several Rosales that have not preserved genome duplications in more than 100 million years; however, a neopolyploid series found in the mulberry tree and several others suggest that new duplications may confer benefits. Five predicted mulberry miRNAs are found in the haemolymph and silk glands of the silkworm, suggesting interactions at molecular levels in the plant–herbivore relationship. The identification and analyses of mulberry genes involved in diversifying selection, resistance and protease inhibitor expressed in the laticifers will accelerate the improvement of mulberry plants

The Potential and Approach of Flue Gas Waste Heat Utilization of Natural Gas for Space Heating

AbstractAfter the combustion of natural gas, the flue gas contains large amounts of water vapor. The latent heat of the water vapor in the flue gas account for 10%-11% of the lower heating value of natural gas, that is, if the condensing heat of the flue gas were recovered, the energy efficiency could be improved greatly. In order to improve the efficiency of the space heating system by natural gas, the potential of waste heat of the flue gas were analyzed, and the problems of the conventional space heating system were proposed. A new approach was proposed, which could decrease the temperature of the flue gas, and recover the waste heat of the flue gas simultaneously. The flue gas outlet temperature could be reduced to below 25°C. The different processes were proposed for gas boiler, distributed energy system, and natural gas cogeneration systems. The energy saving analysis and economic evaluation were investigated. A remarkable economic advantage can be achieved in this technology. The payback year is within 4 years. It provides the important reference for reasonable application of the technique

Thermal Fatigue Damage and Residual Mechanical Properties of WCu45/FeCr18Ni9 Steel Brazed Joint with NiCrSiBFe Filler Metal

Thermal fatigue properties of WCu45/ FeCr18Ni9 steel brazed joint with Ni-Cr-Si-B filler metal were investigated. Results indicated that the fatigue damage of Ni-based joint was aggravated with the increased of thermal fatigue cycles times. Moreover, the fatigue cracks appeared in the brazing seam and FeCr18Ni9 steel side near the brazing seam, and the bending strength of the brazed joint decreased from 333 MPa of original joint to 160 MPa of having experienced 200 thermal fatigue cycles. The fracture characteristic of Ni-based joint underwent 200 cycles was identified as mixed ductile-brittle fracture under the combined effect of external bending load and internal fatigue damage

Time Course Transcriptome Changes in <i>Shewanella algae</i> in Response to Salt Stress

<div><p><i>Shewanella algae</i>, which produces tetrodotoxin and exists in various seafoods, can cause human diseases, such as spondylodiscitis and bloody diarrhea. In the present study, we focused on the temporal, dynamic process in salt-stressed <i>S. algae</i> by monitoring the gene transcript levels at different time points after high salt exposure. Transcript changes in amino acid metabolism, carbohydrate metabolism, energy metabolism, membrane transport, regulatory functions, and cellular signaling were found to be important for the high salt response in <i>S. alga</i>e. The most common strategies used by bacteria to survive and grow in high salt environments, such as Na⁺ efflux, K⁺ uptake, glutamate transport and biosynthesis, and the accumulation of compatible solutes, were also observed in <i>S. algae.</i> In particular, genes involved in peptidoglycan biosynthesis and DNA repair were highly and steadily up-regulated, accompanied by rapid and instantaneous enhancement of the transcription of large- and small-ribosome subunits, which suggested that the structural changes in the cell wall and some stressful responses occurred in <i>S. algae</i>. Furthermore, the transcription of genes involved in the tricarboxylic acid (TCA) cycle and the glycolytic pathway was decreased, whereas the transcription of genes involved in anaerobic respiration was increased. These results, demonstrating the multi-pathway reactions of <i>S. algae</i> in response to salt stress, increase our understanding of the microbial stress response mechanisms.</p></div