Chromosome 5P of Agropyron cristatum induces chromosomal translocation by disturbing homologous chromosome pairing in a common wheat background

Wide hybridization is a strategy for broadening the genetic basis of wheat. Because an efficient method for inducing wheat–alien chromosome translocations will allow producing useful germplasm, it is desirable to discover new genes that induce chromosomal variation. In this study, chromosome 5P from A.cristatum was shown to induce many types of chromosomal structural variation in a common wheat background, including nonhomoeologous chromosome translocations, as revealed by genomic in situ hybridization, fluorescence in situ hybridization, and DNA marker analysis. Aberrant meiosis was associated with chromosomal structural variation, and aberrant meiotic behavior was observed in wheat–A.cristatum 5P monosomic and disomic addition lines, suggesting that the effect of chromosome 5P was independent of the number of chromosome 5P copies. Chromosome 5P disturbed homologous chromosome pairing at pachytene stage in a common wheat background, resulting in a high frequency of univalent formation and reduced crossing over. Thirteen genes involved in DNA repair or chromatin remodeling, including RAD52-like and MSH6 genes, were differentially expressed(upregulated) in wheat–A. cristatum 5P addition lines according to transcriptome analysis, implicating chromosome 5P in the process of meiotic double-strand break repair. These findings provide a new, efficient tool for inducing wheat–alien chromosome translocations and producing new germplasm.

MiR-93-5p in BM-MSCs-derived exosomes amelio­rates renal fibrosis by affecting macrophage polar­ization

MiRNAs and macrophages play important roles in renal fibrosis.The exosomes secreted by bone marrow mesenchymal stem cells(BM-MSCs)can alleviate renal fibrosis.What is not clear,however,is whether a type of miRNAs in the BM-MSCs exosomes can alleviate renal fibrosis by modulating macrophage polarization.First,we take a high-throughput sequencing of miRNAs in exo­somes of BM-MSCs from chronic kidney disease(CKD)and normal people.Then we used the UUO mouse model and injected exosomes into the tail vein.The macrophages were stimulated with lipopolysaccharide(LPS).MSC-Exo or exosomes from BM-MSCs transfected with miR-93-5p inhibitor(Inhi-Exo)were added to the culture medium.The macrophages were transfected with miR-93-5p inhibitor or miR-93-5p mimic alone.The expression of miR-93-5p in exosomes of CKD patients was significantly decreased compared with normal people and in the LPS-stimulated macrophages and UUO mice kidneys.After stimulation with LPS,the macrophages polarized toward M1 subtype.MSC-Exo or miR-93-5p mimic promoted macrophages from M1 to M2 sub­type.Inhi-Exo or miR-93-5p inhibitor blocked the differentiation from M1 to M2 subtype.Significant fibrotic changes occurred in the kidneys of UUO mice,and M1 macrophages were significantly increased.After injecting exosomes into the tail vein of UUO mice,the degree of renal fibrosis was alleviated,the expression of miR-93-5p in the kidney was significantly increased,and the renal macrophages differentiated from M1 to M2 subtype.These results demonstrated that miR-93-5p in the exosomes derived from BM-MSCs can improve renal fibrosis by inducing macrophage differentiation from M1 to M2 subtype.

A Corpus-Based Comparative Study on Lexical Bundles in Native and Chinese Scholars’ English Abstracts——Taking Linguistics and Chemistry as an Example

Based on self-established corpora,the study systematically explores structural and functional similarities and differences of four-word lexical bundles in native and Chinese writers’English abstracts both in chemistry and linguistics from the interdisciplinary and intradisciplinary viewpoint.The results show that disciplinary features are found in the use of lexical bundles.Besides,most bundle differences found in abstracts by English native writers are also found in those written by Chinese scholars,indicating that Chinese scholars have developed an awareness of their discipline.In addition,both structurally and functionally,the lexical bundles in Chinese writers’abstracts are similar to those of native writers in linguistics while divergent in chemistry.