Expression Patterns of a Vernalization-related Genes Responding to Jasmonate

利用RNA原位杂交技术分析了春化相关基因ver2 0 3F在冬小麦 (TriticumaestivumL .cv .JingdongNo .1 )胚芽组织内的表达模式。结果表明 ,ver2 0 3F基因的转录本在春化处理的冬小麦胚芽幼叶中有明显的积累 ,而在胚芽鞘以及生长点处却未见杂交信号。茉莉酸诱导冬小麦胚芽后的基因表达模式与春化处理后的模式相似。实验结果暗示感受春化作用的信号部位可能是胚芽的幼叶 ,细胞对春化的应答与茉莉酸介导的信号转导途径有关。

Loss of micro RNA-124 expression in neurons in the peri-lesion area in mice with spinal cord injury

Micro RNA-124（mi R-124） is abundantly expressed in neurons in the mammalian central nervous system, and plays critical roles in the regulation of gene expression during embryonic neurogenesis and postnatal neural differentiation. However, the expression profile of mi R-124 after spinal cord injury and the underlying regulatory mechanisms are not well understood. In the present study, we examined the expression of mi R-124 in mouse brain and spinal cord after spinal cord injury using in situ hybridization. Furthermore, the expression of mi R-124 was examined with quantitative RT-PCR at 1, 3 and 7 days after spinal cord injury. The mi R-124 expression in neurons at the site of injury was evaluated by in situ hybridization combined with Neu N immunohistochemical staining. The mi R-124 was mainly expressed in neurons throughout the brain and spinal cord. The expression of mi R-124 in neurons significantly decreased within 7 days after spinal cord injury. Some of the neurons in the peri-lesion area were Neu N＋/mi R-124-. Moreover, the neurons distal to the peri-lesion site were Neu N＋/mi R-124＋. These findings indicate that mi R-124 expression in neurons is reduced after spinal cord injury, and may reflect the severity of spinal cord injury.

A novel therapeutic target for peripheral nerve injury-related diseases: aminoacyl-tRNA synthetases

Aminoacyl-t RNA synthetases（Amino ARSs） are essential enzymes that perform the first step of protein synthesis. Beyond their original roles, Amino ARSs possess non-canonical functions, such as cell cycle regulation and signal transduction. Therefore, Amino ARSs represent a powerful pharmaceutical target if their non-canonical functions can be controlled. Using Amino ARSs-specific primers, we screened m RNA expression in the spinal cord dorsal horn of rats with peripheral nerve injury created by sciatic nerve axotomy. Of 20 Amino ARSs, we found that phenylalanyl-t RNA synthetase beta chain（FARSB）, isoleucyl-t RNA synthetase（IARS） and methionyl-t RNA synthetase（MARS） m RNA expression was increased in spinal dorsal horn neurons on the injured side, but not in glial cells. These findings suggest the possibility that FARSB, IARS and MARS, as a neurotransmitter, may transfer abnormal sensory signals after peripheral nerve damage and become a new target for drug treatment.

Single-nucleus RNA and ATAC sequencing analyses provide molecular insights into early pod development of peanut fruit

Peanut(Arachis hypogaea L.)is an important leguminous oil and economic crop that produces flowers aboveground and fruits belowground.Subterranean fruit-pod development,which significantly affects peanut production,involves complex molecular mechanisms that likely require the coordinated regulation of multiple genes in different tissues.To investigate the molecular mechanisms that underlie peanut fruitpod development,we characterized the anatomical features of early fruit-pod development and integrated single-nucleus RNA-sequencing(snRNA-seq)and single-nucleus assay for transposase-accessible chromatin with sequencing(snATAC-seq)data at the single-cell level.We identified distinct cell types,such as meristem,embryo,vascular tissue,cuticular layer,and stele cells within the shell wall.These specific cell types were used to examine potential molecular changes unique to each cell type during pivotal stages of fruit-pod development.snRNA-seq analyses of differentially expressed genes revealed cell-type-specific insights that were not previously obtainable from transcriptome analyses of bulk RNA.For instance,we identified MADS-box genes that contributes to the formation of parenchyma cells and gravity-related genes that are present in the vascular cells,indicating an essential role for the vascular cells in peg gravitropism.Overall,our single-nucleus analysis provides comprehensive and novel information on specific cell types,gene expression,and chromatin accessibility during the early stages of fruit-pod development.This information will enhance our understanding of the mechanisms that underlie fruit-pod development in peanut and contribute to efforts aimed at improving peanut production.

Tissue array for Tp53,C-myc,CCND1 gene over-expression in different tumors

AIM:To rapidly detect molecular alterations in different malignancies and investigate the possible role of Tp53,C-myc,and CCND1 genes in development of tumors in human organs and their adjacent normal tissues,as well as the possible relation between well-and poorly-differentiated tumors.METHODS:A tissue array consisting of seven different tumors was generated.The tissue array included 120 points of esophagus,120 points of stomach,80 points of rectum,60 points of thyroid gland,100 points of mammary gland,80 points of liver,and 80 points of colon.Expressions of Tp53,C-myc,and CCND1 were determined by RNA in situ hybridization.3' terminal digoxin-labeled anti-sense single stranded oligonucleotide and locked nucleic acid modifying probe were used.RESULTS:The expression level of Tp53 gene was higher in six different carcinoma tissue samples than in paracancerous tissue samples with the exception in colon carcinoma tissue samples(P < 0.05).The expression level of CCND1 gene was significantly different in different carcinoma tissue samples with the exception in esophagus and colon carcinoma tissue samples.The expression level of C-myc gene was different in esophagus carcinoma tissue samples(c2 = 18.495,P = 0.000),stomach carcinoma tissue samples(c2 = 23.750,P = 0.000),and thyroid gland tissue samples(c2 = 10.999,P = 0.004).The intensity of signals was also different in different carcinoma tissue samples and paracancerous tissue samples.CONCLUSION:Over-expression of the Tp53,CCND1,and C-myc genes appears to play a role in development of human cancer by regulating the expression of mRNA.Tp53,CCND1 and C-myc genes are significantly correlated with the development of different carcinomas.

用DNA过量核酸分子杂交法对大鼠肝和大鼠肝癌细胞核RNA的比较研究

用DNA过量核酸分子杂交法观察到,大鼠肝癌细胞中重复频率在10~4以上的Poly(A)-核RNA的频率和种类,均比大鼠正常肝细胞有所增加。大鼠肝癌细胞中重复频率在1—4×10~2的Poly(A)-核RNA和Poly(A)^+核RNA的重复频率,比大鼠正常肝细胞减少,而RNA种类则增加。大鼠肝癌细胞中,接近单拷贝的Poly(A)-核RNA和Poly(A)^+核RNA,其频率比大鼠正常肝细胞略有增加,而种类则减少。用总细胞核RNA得类似结果。

Linking circular intronic RNA degradation and function in transcription by RNase H1

Circular intronic RNAs(ci RNAs) escaping from DBR1 debranching of intron lariats are co-transcriptionally produced from prem RNA splicing, but their turnover and mechanism of action have remained elusive. We report that RNase H1 degrades a subgroup of ci RNAs in human cells. Many ci RNAs contain high GC% and tend to form DNA:RNA hybrids(R-loops) for RNase H1 cleavage, a process that appears to promote Pol II transcriptional elongation at ci RNA-producing loci. One ci RNA, ciankrd52, shows a stronger ability of R-loop formation than that of its cognate pre-m RNA by maintaining a locally open RNA structure in vitro. This allows the release of pre-m RNA from R-loops by ci-ankrd52 replacement and subsequent ci RNA removal via RNase H1 for efficient transcriptional elongation. We propose that such an R-loop dependent ci RNA degradation likely represents a mechanism that on one hand limits ci RNA accumulation by recruiting RNase H1 and on the other hand resolves Rloops for transcriptional elongation at some GC-rich ci RNA-producing loci.

ILF3 safeguards telomeres from aberrant homologous recombination as a telomeric R-loop reader

Telomeres are specialized structures at the ends of linear chromosomes that protect genome stability.The telomeric repeat-containing RNA(TERRA)that is transcribed from subtelomeric regions can invade into double-stranded DNA regions and form RNA:DNA hybrid-containing structure called R-loop.In tumor cells,R-loop formation is closely linked to gene expression and the alternative lengthening of telomeres(ALT)pathway.Dysregulated R-loops can cause stalled replication forks and telomere instability.However,how R-loops are recognized and regulated,particularly at telomeres,is not well understood.We discovered that ILF3 selectively associates with telomeric R-loops and safeguards telomeres from abnormal homologous recombination.Knocking out ILF3 results in excessive R-loops at telomeres and triggers telomeric DNA damage responses.In addition,ILF3 deficiency disrupts telomere homeostasis and causes abnormalities in the ALT pathway.Using the proximity-dependent biotin identification(BioID)technology,we mapped the ILF3 interactome and discovered that ILF3 could interact with several DNA/RNA helicases,including DHX9.Importantly,ILF3 may aid in the resolution of telomeric R-loops through its interaction with DHX9.Our findings suggest that ILF3 may function as a reader of telomeric R-loops,helping to prevent abnormal homologous recombination and maintain telomere homeostasis.

Cell-wall Invertases from Rice are Differentially Expressed in Caryopsis during the Grain Filling Stage

Cell-wall invertase plays an important role in sucrose partitioning between source and sink organs in higher plants. To investigate the role of cell-wall invertases for seed development in rice （Oryza sativa L.）, cDNAs of three putative cell- wall invertase genes OsCIN1, OsCIN2 and OsCIN3 were isolated. Semi-quantitative reverse transcription-polymerase chain reaction analysis revealed different expression patterns of the three genes in various rice tissues/organs. In developing caryopses, they exhibited similar temporal expression patterns, expressed highly at the early and middle grain filling stages and gradually declined to low levels afterward. However, the spatial expression patterns of them were very different, with OsCIN1 primarily expressed in the caryopsis coat, OsCIN2 in embryo and endosperm, and OsCIN3 in embryo. Further RNA in situ hybridization analysis revealed that a strong signal of OsCIN2 mRNA was detected in the vascular parenchyma surrounding the xylem of the chalazal vein and the aleurone layer, whereas OsCIN3 transcript was strongly detected in the vascular parenchyma surrounding the phloem of the chalazal vein, cross-cells, the aleurone layer and the nuceUar tissue. These data indicate that the three cell-wall invertase genes play complementary/synergetic roles in assimilate unloading during the grain filling stage. In addition, the cell type-specific expression patterns of OsCIN3 in source leaf blades and anthers were also investigated, and its corresponding physiological roles were discussed.

OIP5-AS1 specifies p53-driven POX transcription regulated by TRPC6 in glioma

Transcription factors(TFs)control an array of expressed genes.However,the specifics of how a gene is expressed in time and space as controlled by a TF remain largely unknown.Here,in TRPC6-regulated proline oxidase 1(POX)transcription in human glioma,we report that OIP5-AS1,a long noncoding RNA,determines the specificity of p53-driven POX expression.The OIP5-AS1/p53 complex via its 24 nucleotides binds to the POX promoter and is necessary for POX expression but not for p21 transcription.An O-site in the POX promoter to which OIP5-AS1 binds was identified that is required for OIP5-AS1/p53 binding and POX transcription.Blocking OIP5-AS1 binding to the O-site inhibits POX transcription and promotes glioma development.Thus,the OIP5-AS1/O-site module decides p53-controlled POX expression as regulated by TRPC6 and affects glioma development.