Natural variation at qHd1 affects heading date acceleration at high temperatures with pleiotropism for yield traits in rice.

BACKGROUND: Rice is highly sensitive to temperature fluctuations. Recently, the frequent occurrence of high temperature stress has heavily influenced rice production. Proper heading date in specific environmental conditions could ensure high grain yield. Rice heading greatly depends on the accurate measurement of environmental changes, particularly in day length and temperature. In contrary to the detailed understanding of the photoperiod pathway, little has been known about how temperature regulates the genetic control of rice heading. RESULTS: Near isogenic lines that were segregated for qHd1, were developed from a cross between indica rice varieties Zhenshan 97 (ZS97) and Milyang 46 (MY46). Using a five sowing-date experiment in the paddy field, we observed the involvement of qHd1 in temperature responses. With the gradual increase of temperature from Trial I to V, heading date of MY46 homozygotes continued to decrease for about 5 d per trial from 76 to 58 d, while that of ZS97 homozygotes was promoted at the same rate from Trial I to III and then stabilized at 69 d. This thermal response was confirmed in a temperature-gradient experiment conducted in the phytotron. It is also found that tolerance of the ZS97 allele to heading acceleration at high temperature was associated with higher grain weight that resulted in higher grain yield. Then, by qRT-PCR and RNA-seq, we found the pathway OsMADS51-Ehd1-RFT1/Hd3a underlying the qHd1-mediated floral response to temperature. By sequence comparison, OsMADS51 for qHd1 displayed a 9.5-kb insertion in the 1st intron of the ZS97 allele compared to the MY46 allele. Furthermore, this large insertion is commonly found in major early-season indica rice varieties, but not in the middle- and late-season ones, which corresponds to the requirement for high-temperature tolerance during the heading and grain-filling stages of early-season rice. CONCLUSIONS: Beneficial alleles at qHd1 confer tolerance to high temperatures at the heading and grain-filling stages, playing a significant role in the eco-geographical adaptation of early-season indica rice during modern breeding. These results, together with the underlying OsMADS51-Ehd1-RFT1/Hd3a floral pathway, provide valuable information for better understanding the molecular mechanism of temperature responsive regulation of heading date and yield traits in rice.

Identification and characterization of 43 novel polymorphic EST-SSR markers for arum lily, Zantedeschia aethiopica (Araceae).

PREMISE OF THE STUDY: A new set of microsatellite or simple sequence repeat (SSR) markers from expressed sequence tags (ESTs) was developed for arum lily (Zantedeschia aethiopica), which is one of the most iconic and widely recognized ornamental plants in the world. • METHODS AND RESULTS: Using 2175 unigenes derived from 4283 random ESTs in arum lily, 166 primer pairs were designed and tested for amplification in 24 accessions from Asia, Europe, and Africa. A total of 43 loci were polymorphic, with the number of alleles per locus ranging from two to 10. The observed heterozygosity, expected heterozygosity, and polymorphism information content ranged from 0.2313 to 0.8480, 0.3034 to 0.8648, and 0.1015 to 0.7364, respectively. • CONCLUSIONS: These novel polymorphic EST-SSR markers will facilitate future studies of genetic variation and molecular-assisted breeding systems in arum lily.

[Optimum extraction technology of total triterpenoids from Hypodematium sinense].

OBJECTIVE: To optimize the extraction technology of total triterpenoids from Hypodematium sinense. METHODS: With 5% vanillin-glacial acetic acid solution and 72% sulfuric acid as chromogenic agent and the content of total tripenoids as index,using single factor experiment and orthogonal test,the optimal extraction condition was determined. RESULTS: The optimal conditions were solid-liquid ratio 1:12, 60% ethanol concentration, and ultrasonic extraction time of 60 min at 60 degrees C. CONCLUSION: The extraction technology is feasible and can be used as extraction process of total triterpenoids from Hypodematium sinense.

Growth, electronic structure and superconductivity of ultrathin epitaxial CoSi2films.

We report growth, electronic structure and superconductivity of ultrathin epitaxial CoSi2films on Si (111). At low coverages, preferred islands with 2, 5 and 6 monolayers height develop, which agrees well with the surface energy calculation. We observe clear quantum well states as a result of electronic confinement and their dispersion agrees well with density functional theory calculations, indicating weak correlation effect despite strong contributions from Co 3delectrons.Ex situtransport measurements show that superconductivity persists down to at least 10 monolayers, with reducedTcbut largely enhanced upper critical field. Our study opens up the opportunity to study the interplay between quantum confinement, interfacial symmetry breaking and superconductivity in an epitaxial silicide film, which is technologically relevant in microelectronics.

The role of PSGL-1 in pathogenesis of systemic inflammatory response and coagulopathy in endotoxemic mice.

INTRODUCTION: Endotoxemia often results in systemic inflammatory response syndrome (SIRS), coagulation disturbance and acute lung injury (ALI), and such a condition is associated with the activation of platelets, leukocytes and vascular endothelial cells (VECs). P-selectin glycoprotein ligand 1 (PSGL-1) is a key regulatory molecule in the activation of platelets, leukocytes and VECs. However, it still remains largely unexplored whether PSGL-1 plays an important role in SIRS, coagulation dysfunction and ALI of endotoxemia. In the present study, we aimed to study the role of PSGL-1 in above-mentioned situations using endotoxemic mice. MATERIALS AND METHODS: An endotoxemia model was established in BALB/c mice via lipopolysaccharide (LPS) administration. Moreover, the mice were simultaneously injected with PSGL-1 antibody for intervention. The survival rate, morphologic changes of lung tissues, platelet-leukocyte adhesion, tissue factor expression on leukocytes, fibrinogen deposition in lung tissues, serum levels of inflammatory factors and the activation of VECs were determined. RESULTS: The results showed that the aggregation and recruitment of platelets and leukocytes in lung tissues, the expression of tissue factor on leukocytes, the serum levels of inflammatory factors, the activation of VECs, and the fibrinogen deposition in lung tissues were increased in endotoxemic mice, which were significantly alleviated by administration of PSGL-1 antibody. Moreover, blockade of PSGL-1 markedly increased survival rate, and alleviated coagulation disturbance and lung injury in endotoxemic mice. CONCLUSIONS: Taken together, PSGL-1 played an important role in pathogenesis of SIRS and coagulation dysfunction and ALI in endotoxemic mice.

The decapeptide CMS001 enhances swimming endurance in mice.

Now peptides achieve distinct advantages over protein in biological application because of its quick and easy absorption, low power, and high activity. Some bioactive peptides had been developed to be used in the management of exercise-related disorders. In this study, we investigated whether the decapeptide CMS001 (Pro-Thr-Thr-Lys-Thr-Tyr-Phe-Pro-His-Phe) isolated from pig spleen had anti-fatigue effects. Male Balb/c mice were administered CMS001 (20 microg/(kgd)(-1) or 5 microg/(kgd)(-1) for 30 d, intraperitoneal injections) and tested in an exhaustive swim time task. In order to examine the mechanisms of CMS001 anti-fatigue effects, we analyzed liver glycogen stores, blood urea nitrogen (BUN) levels, lactic acid levels, ultrastructural integrity, and levels of both a free radical metabolite and an anti-oxidant enzyme. CMS001 treatment prolonged exhaustive swim time, increased liver glycogen levels, reduced BUN levels, and decreased accumulation of lactic acid in the blood, relative to mice injected with only saline. Examination of the ultrastructure of mitochondria and sarcoplasmic reticulum in skeletal and cardiac muscle of CMS001-treated and control mice revealed that CMS001 can reduce the damage to cardiac and skeletal muscle caused by an exhaustive swim challenge, such that the structure of most tissue specimens were normal in the peptide-treated group. Furthermore the free radical analysis after acute exercise indicated that CMS001 treatment decreased malondialdehyde (MDA) and increased superoxide dismutase (SOD) levels. The present findings indicate that the spleen-derived peptide CMS001 has anti-fatigue effects in mice, and further suggest that the mechanism may involve reduction of tissue damaging free radicals in muscle tissues.

[Evaluation of the inhibitory effect of tripeptide tyroservatide on growth of human hepatocellular carcinoma using a hollow fiber assay].

OBJECTIVE: To investigate the inhibitory effect of tyroservatide (YSV) on growth of hepatocellular carcinoma cells. METHODS: In vitro effects of YSV on five human hepatocellular carcinoma cell lines were assayed by MTS. In vivo effects of YSV on 5 human hepatocellular carcinoma cell lines were assayed by hollow fiber tumor model. RESULTS: After treatment with YSV at a dose of 0.1 approximately 1.6 mg/ml, the growth of the five cell lines was significantly inhibited in vitro compared with that of the control group (P < 0.05). Especially, YSL remarkably inhibited the growth of human hepatocellular carcinoma BEL-7402 cells, i.e. the cell growth was inhibited by 63.3% after treatment with YSL at 1.6 mg/ml. The hollow fiber tumor model demonstrated that YSL (320 microg x kg(-1) x d(-1) and 640 microg x kg(-1) x d(-1)) treatment significantly inhibited the in vivo growth of the five cancer cell lines compared with that in the saline control (P < 0.05). YSL showed the highest level of inhibition of human BEL-7402 hepatocellular carcinoma cells, with an inhibitory index of 53.1% at 320 microg x kg(-1) x d(-1). CONCLUSION: As a new method, hollow fiber assay may be used to evaluate the inhibitory effect of drugs on different tumor cells in vivo, rapidly, accurately and economically. Our results provide an instruction and evidence for clinical use of YSV.

[Effect of Krüppel-like factor 4 overexpression on heat stress-induced apoptosis of Raw264.7 macrophages].

OBJECTIVE: To observe the effect of Krüppel-like factor 4 (KLF4) overexpression on heat stress-induced apoptosis of Raw264.7 macrophages. METHODS: The fragment containing full length mouse KLF4 cDNA coding sequence was inserted into the pcDNA3.1 vector and Raw264.7 macrophages were transfected with pcDNA3.1-KLF4 plasmids using lipofectamine.The expression of KLF4 was examined by Western blot in the Raw264.7 macrophages stably transfected with pcDNA3.1- KLF4 plasmids. Raw264.7 cells transfected with pcDNA3.1 and pcDNA3.1-KLF4 were exposed to heat stress (42 degrees C) for 1h and recovered at 37 degrees C for 12h. Flow cytometry, Hoechest 33258 staining assay, and DNA ladder assays were performed to assess the apoptosis. RESULTS: The KLF4 overexpressed Raw264.7 macrophages were established. After the heat stress, flow cytometry showed that apoptotic cells increased significantly in KLF4 overexpressed cells compared with the vector control; Hoechest 33258 staining was characterized with classical changes including apoptotic body, and nuclear condensation. Agarose gel electrophoresis showed that "DNA ladder" could be observed clearly. CONCLUSION: KLF4 overexpression can increase heat stress-induced apoptosis of Raw264.7 macrophages.

Solubility of silybin in aqueous poly(ethylene glycol) solution.

Silybin is a main component in silymarin, which is an antihepatotoxic polyphenolic substance isolated from the milk thistle plant, Silybum marianum. A major problem in the development of an oral solid dosage form of this drug is the extremely poor aqueous solubility. In present work, the solubility of silybin in aqueous poly(ethylene glycol) 6,000 (PEG 6,000) solution at the temperature range from 293.15 to 313.15K was measured by a solid liquid equilibrium method. The aim of this study is to investigate the possible effect of poly(ethylene glycol) concentration and temperature on the solubility of the drug, and to reveal the solubilization capacity of the polymer for the drug. Experimental results reveal that the solubility of silybin increases with the increase both in PEG's concentration and temperature. With the increase in PEG's concentration, the transfer enthalpy and entropy for silybin from water to aqueous PEG solution increases first in a positive region, and then decreases to a negative region. The transfer enthalpy is lower than the entropy term. A modified Universal Quasi Chemical (UNIQUAC) model was used to correlate solubility data.

[CoCl2-induced chemotherapy resistance in SW480 cells and its mechanism].

OBJECTIVE: To observe the proliferation of SW480 cells exposed to different concentrations of CoCl2, and to examine the expression of hypoxiainducible factor-1 alpha (HIF-1alpha) and heme oxygenase-1 (HO-1) during hypoxia to explore the chemotherapy resistance effect and role of HIF-1alpha and HO-1. METHODS: Methyl thiazolyl tetrazolium (MTF) method was used to detect the proliferation of SW480 cells in the presence of fluorouracil (FU). RT-PCR was applied to examine the expression of HIF-1alpha and HO-1 mRNA in hypoxia. RESULTS: SW480 cells were proliferated at a slow rate, and had a strong resistance to FU with the increase of CoCl2. RT-PCR showed that the up-regulated expression of HIF-1alpha and HO-1 mRNA was consistent with the dose-effect curve and time-effect curve. CONCLUSION: The hypoxia induced by CoCl2 can inhibit the proliferation of SW480, and it can also decrease the sensitivity of the cell to FU. The mechanism is probably related to the up-regulated expression of HIF-1alpha and HO-1 mRNA.

[Screen of inflammatory genes regulated by heat shock factor 1 and corroboration with SOCS3 gene].

OBJECTIVE: To screen the inflammatory mediators genes regulated by HSF1, and explore the mechanism of downstream genes regulated by HSF1. METHODS: HSF-/- and HSF1+/+ mice were injected with 15 mg/kg LPS intraperitoneally (ip), respectively, and were treated as previous after HSR. The total RNA of lung tissues were extracted and filtrated by SuperArray gene Microarry. The promoter of candidate genes were analyzed by transcription element search software to search for heat shock element (HSE). Select the suppressor of cytokine signaling 3 (SOCS3) with HSE. Macrophage cells were stimulated with 400 ng/mL LPS, and were treated as previous after HSR, then the total RNA was extracted respectively. RT-PCR and northern blot assay were performed to detect the expression levels of SOCS3 mRNA. RESULTS: Fifteen genes were repressed by HSF1, including 9 genes with complete HSE. Eleven genes were accelerated by HSF1 possibly, including 8 genes with complete HSE. The promoter of SOCS3 gene contained one complete HSE. LPS stimulation obviously increased the levels of SOCS3 mRNA in macrophages of RAW264.7 mice, which was inhibited by HSR and over-expression of HSF1. CONCLUSION: HSR or HSF1 inhibits LPS induced expression of SOCS3 mRNA; HSF1 might inhibit LPS-induced expression of SOCS3 mRNA by binding to HSE in the promoter of SOCS3 gene.

[Immortalization of embryonic fibroblasts in heat shock transcription factor 1 knockout mouse].

OBJECTIVE: To establish immortalized embryonic fibroblast lines in heat shock transcription factor 1 (HSF1) HSF1-/- and HSF1+/+ mice and to provide experimental models to study the function of HSF1. METHODS: A mammalian expression vector (pSV3neo) containing the SV40 large T antigen was used to transfect the HSF1-/- and HSF1+/+ mouse embryonic fibroblast using Lipofectamine 2000. Colonies were screened by G418 and expanded to immortalized cell lines. PCR was used to detect the integration of the large T antigen with genome in the mouse embryonic fibroblast. Expression of SV40 large T antigen gene in expanded cells was identified by RT-PCR. HSP70 expression was examined by Western blot in the embryonic fibroblast lines. RESULTS: The stable growth and serial propagation were observed in the HSF1-/- and HSF1+/+ cell lines for six months. The mRNA of SV40 T antigen gene expressed in the two cell lines. HSP70 expression could not be induced in the heat-treated HSF1-/- mouse embryo fibroblasts. CONCLUSION: The immortalized cells of HSF1+/+ and HSF1-/- mouse embryo fibroblasts are successfully established.

[Characteristics and expression of Mip5, a novel gene associated with myocardial ischemia/reperfusion in rats].

OBJECTIVE: To determine the characteristics of a novel gene Mip5 (GenBank accession number AY553870) and its expression under physiological and pathological conditions. METHODS: The characteristics of Mip5 were analyzed by bioinformatic programs including BLAST, spidey, psort, ClustalW and so on. RT-PCR was performed to detect Mip5 expression. RESULTS: Bioinformatic analysis showed that Mip5 gene lied in the 13th chromosome and contained 8 exons and 7 introns, its open reading frame contained 909 bp and its protein production was 302 amino acid residues including 6 kelth domains. Under normal conditions, MIP5 expressed abundantly in the heart, brain and kidney, but its expression could not be detected in the liver and muscle. Expression of Mip5 gene was increased significantly after ischemia-reperfusion compared with the sham groups, and reached its peak at 3 h and recovered at 12 h after the reperfusion. Conclusion Mip5 gene is a novel gene containing a putative open reading frame of 302 amino acids residues and may play an important role in rat cardiomyocytes suffering ischemia processing.

Cloning of Human Myelin Protein Zero-like Genes by Bioinformatics Strategy.

To clone novel myelin protein related genes, two human ESTs, which shared significant similarity with the human myelin protein zero gene, were found by the comparison of homologue between the cDNA coding region sequences of MPZ gene and the EST database of NCBI. An 801 bp EST contig was assembled, which was 100% identical with a 128 kb genomic sequence, mapped to 1q24. A 435 bp open reading frame (ORF) within the 801 bp contig was shown by computer analysis. Two primers designed according to the sequence of the contig, were coupled with the primers(lambdagt10-5 and gt10-5) on the sequences flanking cloning site of the cDNA library vector to amplify the cDNA library sequences by nested PCR. New primers, designed based on novel cDNA sequences, were used for the PCR amplification with lambdagt10-5 and gt10-5 in the same way as above. Finally, the human myelin protein zero like gene isoform I and II (MPZL1a, MPZL1b GenBank AF095727, AF092424) were cloned. Comparison of gene and protein structures between MPZL1 and MPZ revealed that MPZL1 is the second member of MPZ family. Mutation analysis of MPZL1 gene was performed in 24 Charcot-Marie-Tooth disease (CMT) families and 26 nonsyndrome deafness families, but no mutation was found.

[In silicon cloning of the human TECTB gene].

The coding sequence of the mouse Tectb and chick Tectb gene were subjected to Blastn searching against the human dbEST and Htgs in NCBI. One BAC clone sequence(GenBank: AL157786) was obtained, which shows high homology to the two genes. We predicted the exons and introns in the homologous region of AL157786 using GENSCAN, MZEF and Blast 2 sequence program, and then assembled the predicted exons into the coding sequence of the human TECTB. The open reading frame of human TECTB gene is 990 bp composed of ten exons, which encodes a protein of 329 amino acids. Human TECTB gene shows 88.1% identity in 990 bp overlap with that of the mouse Tectb gene and the predicted polypeptide shows 94.2% identity in 329 as with the mouse beta-tectorin. The TECTB gene was mapped to human chromosome 10q25 by electronic-PCR.

[Screen selection of target genes regulated by HSF1 in heat shock response from myocardium of gene knockout mice].

OBJECTIVE: To screen select target genes regulated by heat shock transcription factor 1 (HSF1 ) in heat shock response from myocardium of HSF1 gene knockout mice using cDNA chip. METHODS: HSF1 knockout mice were subjected to heat shock treatment (42 degrees C for 15 minutes, and recovered for 3 hours), and cDNA chip containing 15 000 mouse cDNAs were employed to investigate the expression of genes regulated by HSF1 in the myocardium. Then 4 of the differentially expressed genes in the myocardium of HSF1 knockout mice were further confirmed by RT-PCR. The promoter regions of the differentially expressed genes were analysed by TESS software to find HSE. RESULTS: Three hundred and ninety-eight genes were down - regulated in the myocardium of HSF1 knockout mice in heat shock response,with 173 known. Whereas 641 genes were up-regulated in the myocardium, with 235 known. The 5 down-regulated genes and 6 up-regulated ones were shown to contain HSE in their promoter regions. CONCLUSION: In heat shock response, expression of multiple genes is regulated directly or indirectly by HSF1.

Research progress of MSCs-derived exosomes carrying miRNAs in the repair of cartilage degeneration / 医学研究生学报

The incidence of cartilage degeneration (osteoarthritis, etc.) is increasing year by year, putting heavy pressure on families and society. It has become a consensus that mesenchymal stem cells can repair damaged cartilage. As the research progresses, more and more evidence indicates that its effects are attributed to the paracrine system, especially the exosomes. Exosomes are a lipid bilayer cystic structure encapsulating biologically active factors such as proteins, lipids, mRNA, and microRNAs (miRNAs/miRs), which can regulate the biological functions of cells. As a signal and carrier for transmitting important information between cells, it plays a very important role in the repair of cartilage degeneration damage. This paper reviews the research of mesenchymal stem cell-derived exosomes carrying miRNAs in the repair of cartilage injury.

Recent advancements in optofluidics-based single-cell analysis: optical on-chip cellular manipulation, treatment, and property detection.

Cellular analysis plays important roles in various biological applications, such as cell biology, drug development, and disease diagnosis. Conventional cellular analysis usually measures the average response from a whole cell group. However, bulk measurements may cause misleading interpretations due to cell heterogeneity. Another problem is that current cellular analysis may not be able to differentiate various subsets of cell populations, each exhibiting a different behavior than the others. Single-cell analysis techniques are developed to analyze cellular properties, conditions, or functional responses in a large cell population at the individual cell level. Integrating optics with microfluidic platforms provides a well-controlled microenvironment to precisely control single cell conditions and perform non-invasive high-throughput analysis. This paper reviews recent developments in optofluidic technologies for various optics-based single-cell analyses, which involve single cell manipulation, treatment, and property detection. Finally, we provide our views on the future development of integrated optics with microfluidics for single-cell analysis and discuss potential challenges and opportunities of this emerging research field in biological applications.

Competitive ability and fitness differences between two introduced populations of the invasive whitefly Bemisia tabaci Q in China.

BACKGROUND: Our long-term field survey revealed that the Cardinium infection rate in Bemisia tabaci Q (also known as biotype Q) population was low in Shandong, China over the past few years. We hypothesize that (1) the Cardinium-infected (C+) B. tabaci Q population cannot efficiently compete with the Cardinium-uninfected (C-) B. tabaci Q population; (2) no reproductive isolation may have occurred between C+ and C-; and (3) the C- population has higher fitness than the C+ population. METHODOLOGY AND RESULTS: To reveal the differences in competitive ability and fitness between the two introduced populations (C+ and C-), competition between C+ and C- was examined over several generations. Subsequently, the reproductive isolation between C+ and C- was studied by crossing C+ with C- individuals, and the fitnesses of C+ and C- populations were compared using a two-sex life table method. Our results demonstrate that the competitive ability of the C+ whiteflies was weaker than that of C-. There is that no reproductive isolation occurred between the two populations and the C- population had higher fitness than the C+ population. CONCLUSION: The competitive ability and fitness differences of two populations may explain why C- whitefly populations have been dominant during the past few years in Shandong, China. However, the potential role Cardinium plays in whitefly should be further explored.

Workable male sterility systems for hybrid rice: Genetics, biochemistry, molecular biology, and utilization.

The exploitation of male sterility systems has enabled the commercialization of heterosis in rice, with greatly increased yield and total production of this major staple food crop. Hybrid rice, which was adopted in the 1970s, now covers nearly 13.6 million hectares each year in China alone. Various types of cytoplasmic male sterility (CMS) and environment-conditioned genic male sterility (EGMS) systems have been applied in hybrid rice production. In this paper, recent advances in genetics, biochemistry, and molecular biology are reviewed with an emphasis on major male sterility systems in rice: five CMS systems, i.e., BT-, HL-, WA-, LD- and CW- CMS, and two EGMS systems, i.e., photoperiod- and temperature-sensitive genic male sterility (P/TGMS). The interaction of chimeric mitochondrial genes with nuclear genes causes CMS, which may be restored by restorer of fertility (Rf) genes. The PGMS, on the other hand, is conditioned by a non-coding RNA gene. A survey of the various CMS and EGMS lines used in hybrid rice production over the past three decades shows that the two-line system utilizing EGMS lines is playing a steadily larger role and TGMS lines predominate the current two-line system for hybrid rice production. The findings and experience gained during development and application of, and research on male sterility in rice not only advanced our understanding but also shed light on applications to other crops.