40 research outputs found
Improving Image Captioning with Conditional Generative Adversarial Nets
In this paper, we propose a novel
conditional-generative-adversarial-nets-based image captioning framework as an
extension of traditional reinforcement-learning (RL)-based encoder-decoder
architecture. To deal with the inconsistent evaluation problem among different
objective language metrics, we are motivated to design some "discriminator"
networks to automatically and progressively determine whether generated caption
is human described or machine generated. Two kinds of discriminator
architectures (CNN and RNN-based structures) are introduced since each has its
own advantages. The proposed algorithm is generic so that it can enhance any
existing RL-based image captioning framework and we show that the conventional
RL training method is just a special case of our approach. Empirically, we show
consistent improvements over all language evaluation metrics for different
state-of-the-art image captioning models. In addition, the well-trained
discriminators can also be viewed as objective image captioning evaluatorsComment: 12 pages; 33 figures; 36 refenences; Accepted by AAAI201
Physiological Responses and Tolerance Evaluation of Five Poplar Varieties to Waterlogging
Waterlogging resistance of five poplar varieties, âDanhongyangâ (DHY), âJuba-261â (JB-261), âZongqiansanhaoâ (ZQ-3), âZhonglin-2025â (ZL-2025), and âNanlin-895â (NL-895), was evaluated under the simulated waterlogging conditions. Data on changes in leaf color and morphology as well as in biochemical indices, such as chlorophyll, malonaldehyde, soluble protein, soluble sugar content, superoxide dismutase (SOD), peroxidases (POD), ascorbate peroxidase (APX), glutathione reductase (GR), and glutathione peroxidase (GSH-PX) activities, relevant to submergence stress, were analyzed. The principal component analysis of the data identified the waterlogging resistance coefficient of the indices, which showed that waterflooding brought about different degrees of damage in the five poplar varieties, with DHY having the lowest waterlogging index. The leaf pigment content of the poplar was remarkably decreased by waterlogging, whereas malondialdehyde (MDA) and proline contents were enhanced, but in different extents among the poplar varieties. Nearly all other poplar varieties showed a tendency of decline in JB-261, ZQ-3, ZL-2025, NL-895, except for SOD activity in DHY, which increased under submergence stress. Poplar varieties had varying degree of changes in POD activity, and APX activity tended to increase upon waterlogging. GR also displayed increasing tendency in JB-261, ZL-2025 and NL-895, except for in ZQ-3, which declined under waterlogging stress. GSH-PX except for ZQ-3 displayed no significant change, which showed a tendency of decline in DHY, JB-261, ZL-2025, and NL895. Principal component analysis allowed us to reduce16 indices to four independent indices. The subordinate function analysis identified that the DHY variety had the highest waterlogging tolerance, whereas the NL-895 variety had the lowest waterlogging tolerance among tested varieties
Advance in mechanism of plant leaf colour mutation
As a common mutation trait in plants, leaf colour mutation is related to the degree of chlorophyll and anthocyanin changes and the destruction of chloroplast structure. This study summarizes the latest research progress in leaf colour mutation mechanism, including the metabolic basis of plant leaf colour mutation, leaf colour mutation caused by gene mutation in the chlorophyll metabolism pathway, leaf colour mutation caused by blocked chloroplast development, leaf colour mutation controlled by key transcription factors and non-coding RNAs, leaf colour mutation caused by environmental factors, and leaf colour mutation due to the involvement of the mevalonate pathway. These results will lay a theoretical foundation for leaf colour development, leaf colour improvement, and molecular breeding for leaf colour among tree species
Fluoxetine improves behavioural deficits induced by chronic alcohol treatment by alleviating RNA editing of 5-HT2C receptors
Deep functional analysis of synII, a 770-kilobase synthetic yeast chromosome
INTRODUCTION
Although much effort has been devoted to studying yeast in the past few decades, our understanding of this model organism is still limited. Rapidly developing DNA synthesis techniques have made a âbuild-to-understandâ approach feasible to reengineer on the genome scale. Here, we report on the completion of a 770-kilobase synthetic yeast chromosome II (synII). SynII was characterized using extensive Trans-Omics tests. Despite considerable sequence alterations, synII is virtually indistinguishable from wild type. However, an up-regulation of translational machinery was observed and can be reversed by restoring the transfer RNA (tRNA) gene copy number.
RATIONALE
Following the âdesign-build-test-debugâ working loop, synII was successfully designed and constructed in vivo. Extensive Trans-Omics tests were conducted, including phenomics, transcriptomics, proteomics, metabolomics, chromosome segregation, and replication analyses. By both complementation assays and SCRaMbLE (synthetic chromosome rearrangement and modification by
loxP
-mediated evolution), we targeted and debugged the origin of a growth defect at 37°C in glycerol medium.
RESULTS
To efficiently construct megabase-long chromosomes, we developed an I-
Sce
Iâmediated strategy, which enables parallel integration of synthetic chromosome arms and reduced the overall integration time by 50% for synII. An I-
Sce
I site is introduced for generating a double-strand break to promote targeted homologous recombination during mitotic growth. Despite hundreds of modifications introduced, there are still regions sharing substantial sequence similarity that might lead to undesirable meiotic recombinations when intercrossing the two semisynthetic chromosome arm strains. Induction of the I-
Sce
Iâmediated double-strand break is otherwise lethal and thus introduced a strong selective pressure for targeted homologous recombination. Since our strategy is designed to generate a markerless synII and leave the
URA3
marker on the wild-type chromosome, we observed a tenfold increase in
URA3
-deficient colonies upon I-
Sce
I induction, meaning that our strategy can greatly bias the crossover events toward the designated regions.
By incorporating comprehensive phenotyping approaches at multiple levels, we demonstrated that synII was capable of powering the growth of yeast indistinguishably from wild-type cells (see the figure), showing highly consistent biological processes comparable to the native strain. Meanwhile, we also noticed modest but potentially significant up-regulation of the translational machinery. The main alteration underlying this change in expression is the deletion of 13 tRNA genes.
A growth defect was observed in one very specific conditionâhigh temperature (37°C) in medium with glycerol as a carbon sourceâwhere colony size was reduced significantly. We targeted and debugged this defect by two distinct approaches. The first approach involved phenotype screening of all intermediate strains followed by a complementation assay with wild-type sequences in the synthetic strain. By doing so, we identified a modification resulting from PCRTag recoding in
TSC10
, which is involved in regulation of the yeast high-osmolarity glycerol (HOG) response pathway. After replacement with wild-type
TSC10
, the defect was greatly mitigated. The other approach, debugging by SCRaMbLE, showed rearrangements in regions containing HOG regulation genes. Both approaches indicated that the defect is related to HOG response dysregulation. Thus, the phenotypic defect can be pinpointed and debugged through multiple alternative routes in the complex cellular interactome network.
CONCLUSION
We have demonstrated that synII segregates, replicates, and functions in a highly similar fashion compared with its wild-type counterpart. Furthermore, we believe that the iterative âdesign-build-test-debugâ cycle methodology, established here, will facilitate progression of the Sc2.0 project in the face of the increasing synthetic genome complexity.
SynII characterization.
(
A
) Cell cycle comparison between synII and BY4741 revealed by the percentage of cells with separated CEN2-GFP dots, metaphase spindles, and anaphase spindles. (
B
) Replication profiling of synII (red) and BY4741 (black) expressed as relative copy number by deep sequencing. (
C
) RNA sequencing analysis revealed that the significant up-regulation of translational machinery in synII is induced by the deletion of tRNA genes in synII.
</jats:sec
Identification and expression of the trehalose-6-phosphate synthase gene family members in tomato exposed to different light spectra
Identification and expression of the trehalose-6-phosphate synthase gene family members in tomato exposed to different light spectra
Light is the source of energy for plants. Light wavelengths, densities and
irradiation periods act as signals directing morphological and physiological
characteristics during plant growth and development. To evaluate the effects
of light wavelengths on tomato growth and development, Solanum lycopersicum
(cv. micro-Tom) seedlings were exposed to different light-quality
environments, including white light and red light supplemented with blue
light (at ratios of 3:1 and 8;1, respectively). Tomatoes grown under red
light supplemented with blue light displayed significantly shorter stem
length, a higher number of flower buds and rate of fruit set, but an
extremely late flowering compared to white-light-grown plants. To illustrate
the mechanism underlying the inhibition of stem growth and floral transition
mediated by red/blue light, 10 trehalose-6-phosphate synthase (TPS) genes
were identified in tomato, and bioinformatics analysis was performed. qRT-PCR
analysis showed that SlTPSs were expressed widely throughout plant
development and SlTPS1 was expressed at extremely high levels in stems and
buds. Further analysis of several flowering-associated genes and microRNAs
showed that the expressions of SlTPS1, SlFT and miR172 were significantly
downregulated in tomato grown under red and blue light compared with those
grown under white light, whereas miR156 transcript levels were increased. A
regulatory model underlying vegetative growth and floral transition regulated
by light qualities is presented. Our data provide evidence that light quality
strongly affects plant growth and phase transition, most likely via the
TPS1-T6P signaling pathway
Transcriptome Analysis Reveals Molecular Signatures of Luteoloside Accumulation in Senescing Leaves of Lonicera macranthoides
Lonicera macranthoides is an important medicinal plant widely used in traditional Chinese medicine. Luteoloside is a critical bioactive compound in L. macranthoides. To date, the molecular mechanisms underlying luteoloside biosynthesis are still largely unknown. In this work, high performance liquid chromatography (HPLC) was employed to determine the luteoloside contents in leaves, stems, and flowers at different developmental stages. Results showed that senescing leaves can accumulate large amounts of luteoloside, extremely higher than that in young and semi-lignified leaves and other tissues. RNA-Seq analysis identified that twenty-four differentially expressed unigenes (DEGs) associated with luteoloside biosynthesis were significantly up-regulated in senescing leaves, which are positively correlated with luteoloside accumulation. These DEGs include phenylalanine ammonia lyase 2, cinnamate 4-hydroxylase 2, thirteen 4-coumarate-CoA ligases, chalcone synthase 2, six flavonoid 3â˛-monooxygenase (F3â˛H) and two flavone 7-O-β-glucosyltransferase (UFGT) genes. Further analysis demonstrated that two F3â˛Hs (CL11828.Contig1 and CL11828.Contig2) and two UFGTs (Unigene2918 and Unigene97915) might play vital roles in luteoloside generation. Furthermore, several transcription factors (TFs) related to flavonoid biosynthesis including MYB, bHLH and WD40, were differentially expressed during leaf senescence. Among these TFs, MYB12, MYB75, bHLH113 and TTG1 were considered to be key factors involved in the regulation of luteoloside biosynthesis. These findings provide insights for elucidating the molecular signatures of luteoloside accumulation in L. macranthoides
The complete chloroplast genome of Zanthoxylum piasezkii Maxim. (Rutaceae) and its phylogenetic analysis
Zanthoxylum piasezkii Maxim. is a widely distributed species of edible medicinal plant in China. It has been used for traditional spicy condiment and medicinal ingredients for quite a long time. In this study, the complete chloroplast genome sequence of Z. piasezkii was first reported and characterized from sequencing data. The complete chloroplast genome was determined to be 158,728âbp in length, consisting of a large single-copy (LSC) region (85,918âbp) and a small single copy (SSC) region (17,612âbp), which were separated by a pair of 27,599âbp inverted repeat (IR) regions. The chloroplast genome is predicted to contain 132 genes, including 87 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The overall GC content of cpDNA is 38.4%. The phylogenetic analysis of 12 complete chloroplast genomes reveals that Z. piasezkii is mostly related to the congeneric Z. bungeanum
Constructing the Logical Regression Model to Predict the Target of Jianpi Jiedu Decoction in the Treatment of Hepatocellular Carcinoma
Objectives. The purpose of this study was to identify the molecular mechanism and prognosis-related genes of Jianpi Jiedu decoction in the treatment of hepatocellular carcinoma. Methods. The gene expression data of hepatocellular carcinoma samples and normal tissue samples were downloaded from TCGA database, and the potential targets of drug composition of Jianpi Jiedu decoction were obtained from TCMSP database. The genes were screened out in order to obtain the expression of these target genes in patients with hepatocellular carcinoma. The differential expression of target genes was analyzed by R software, and the genes related to prognosis were screened by univariate Cox regression analysis. Then, the LASSO model was constructed for risk assessment and survival analysis between different risk groups. At the same time, independent prognostic analysis, GSEA analysis, and prognostic analysis of single gene in patients with hepatocellular carcinoma were performed. Results. 174 compounds of traditional Chinese medicine were screened by TCMSP database, corresponding to 122 potential targets. 39 upregulated genes and 9 downregulated genes were screened out. A total of 20 candidate prognostic related genes were screened out by univariate Cox analysis, of which 12 prognostic genes were involved in the construction of the LASSO regression model. There was a significant difference in survival time between the high-risk group and low-risk group (p<0.05). Among the genes related to prognosis, the expression levels of CCNB1, NQO1, NUF2, and CHEK1 were high in tumor tissues (p<0.05). Survival analysis showed that the high expression levels of these four genes were significantly correlated with poor prognosis of HCC (p<0.05). GSEA analysis showed that the main KEGG enrichment pathways were lysine degradation, folate carbon pool, citrate cycle, and transcription factors. Conclusions. In the study, we found that therapy target genes of Jianpi Jiedu decoction were mainly involved in metabolism and apoptosis in hepatocellular carcinoma, and there was a close relationship between the prognosis of hepatocellular carcinoma and the genes of CCNB1, NQO1, NUF2, and CHEK1