33 research outputs found
The reduced ring of the -graded -equivariant stable stems
We describe in terms of generators and relations the ring structure of the
-graded -equivariant stable stems modulo the
ideal of all nilpotent elements. As a consequence, we also record the ring
structure of the homotopy groups of the rational -equivariant sphere
.Comment: 13 page
Histone Lysine Methyltransferase SDG8 Is Involved in Brassinosteroid-Regulated Gene Expression in Arabidopsis thaliana
Citation: Wang, X., Chen, J., Xie, Z., Liu, S., Nolan, T., Ye, H., et al. (2014). Histone lysine
methyltransferase SDG8 is involved in brassinosteroid- regulated gene expression in
arabidopsis thaliana.The plant steroid hormones, brassinosteroids (BRs), play important roles in plant growth, development and responses to environmental stresses. BRs signal through receptors localized to the plasma membrane and other signaling components to regulate the BES1/BZR1 family of transcription factors, which modulates the expression of 4,000-5,000 genes. How BES1/BZR1 and their interacting proteins function to regulate the large number of genes are not completely understood. Here we report that histone lysine methyltransferase SDG8, implicated in Histone 3 lysine 36 di- and tri-methylation (H3K36me2 and me3), is involved in BR-regulated gene expression. BES1 interacts with SDG8, directly or indirectly through IWS1, a transcription elongation factor involved in BR-regulated gene expression. The knockout mutant sdg8 displays a reduced growth phenotype with compromised BR responses. Global gene expression studies demonstrated that SDG8 plays a major role in BR-regulated gene expression as more than half of BR-regulated genes are differentially affected in sdg8 mutant. A Chromatin Immunoprecipitation (ChIP) experiment showed that H3K36me3 is reduced in BR-regulated genes in the sdg8 mutant. Based on these results, we propose that SDG8 plays an essential role in mediating BR-regulated gene expression. Our results thus reveal a major mechanism by which histone modifications dictate hormonal regulation of gene
expression
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The reduced ring of the R O ( C 2 ) RO(C_2) -graded C 2 C_2 -equivariant stable stems
We describe in terms of generators and relations the ring structure of the
R
O
(
C
2
)
RO(C_2)
-graded
C
2
C_2
-equivariant stable stems
π
⋆
C
2
\pi _\star ^{C_2}
modulo the ideal of all nilpotent elements. As a consequence, we also record the ring structure of the homotopy groups of the rational
C
2
C_2
-equivariant sphere
π
⋆
C
2
(
S
Q
)
\pi _\star ^{C_2}(\mathbb {S}_\mathbb {Q})
Genome-Wide Identification and Expression of the PIN Auxin Efflux Carrier Gene Family in Watermelon (Citrullus lanatus)
As one of the world’s most popular fruits, watermelon (Citrus lanatus) is cultivated in more than 3 million hectares across the globe, with a yearly yield of more than 100 million tons. According to ‘97103’ genome version 1, a previous study has shown that the watermelon genome consists of 11 PIN genes. However, the higher quality ‘97103’ genome version 2 was recently assembled by using PacBio long reads with the benefit of fast development sequencing technology. Using this new assembly, we conducted a new genome-wide search for PIN genes in watermelon and compared it with cucumber and melon genomes. We identified nine, nine, and eight PINs in watermelon, cucumber, and melon, respectively. Phylogenetic analysis revealed a distinct evolutionary history of PIN proteins in watermelon, which is shown by the orphan PIN6 in watermelon. We further conducted an expression analysis of the watermelon PIN genes in silico and by qRT-PCR. ClaPIN6 might not play an essential role during shoot regeneration, which is closely related to species-specific evolution. However, the up-regulated expression patterns of ClaPIN1-1 and ClaPIN1-3 indicated their important roles during shoot regeneration. The result of this research will benefit future studies to understand the regulating mechanisms of auxin in watermelon shoot regeneration
Assessment and optimization of electroporation-assisted tumoral nanoparticle uptake in a nude mouse model of pancreatic ductal adenocarcinoma.
Pancreatic ductal adenocarcinoma (PDAC) is a particularly lethal form of cancer. In 2012, the incidence of PDAC was 43,920. Five-year survival for patients with PDAC is around 6%, regardless of staging, making PDAC one of the deadliest forms of cancer. One reason for this dismal prognosis is chemoresistance to the current first-line therapy, gemcitabine. There are multiple factors that contribute to the chemoresistance observed in pancreatic cancer. Among them, desmoplasia has been increasingly seen as a significant contributor to chemoresistance. To overcome desmoplastic chemoresistance, several novel methods of treatment have been developed. Electroporation is one such novel treatment. High electrical fields are applied to cells to create pores that increase cell permeability. It has been previously demonstrated that electroporation enhances the therapeutic efficacy of anticancer drugs in pancreatic tumor models. Nanoparticle-based drug delivery systems constitute a second novel method to overcome desmoplastic chemoresistance. Due to their intrinsic design advantages, nanoparticles have been shown to increase the effectiveness of chemotherapeutic agents, while further reducing or even eliminating side effects. To date, there have been no studies evaluating the cumulative effect of combining both nanoparticle and electroporation strategies to overcome chemoresistance in PDAC. Our preliminary studies assessed the in vitro and in vivo uptake of doxorubicin-loaded iron oxide nanoparticles as a function of electroporation voltage and timing of administration in pancreatic adenocarcinoma cells. Our studies demonstrated that addition of electroporation to administration of nanoparticles significantly increased the amount of intracellular iron oxide nanoparticle uptake by a PANC-1 cell line in an athymic nude mouse model of PDAC. Further, electroporation-assisted nanoparticle uptake could be significantly altered by changing the timing of application of electroporation
Genome-Wide Analysis and Expression of Cyclic Nucleotide–Gated Ion Channel (CNGC) Family Genes under Cold Stress in Mango (Mangifera indica)
The ‘king of fruits’ mango (Mangifera indica) is widely cultivated in tropical areas and has been threatened by frequent extreme cold weather. Cyclic nucleotide–gated ion channel (CNGC) genes have an important function in the calcium-mediated development and cold response of plants. However, few CNGC-related studies are reported in mango, regardless of the mango cold stress response. In this study, we identified 43 CNGC genes in mango showing tissue-specific expression patterns. Five MiCNGCs display more than 3-fold gene expression induction in the fruit peel and leaf under cold stress. Among these, MiCNGC9 and MiCNGC13 are significantly upregulated below 6 °C, suggesting their candidate functions under cold stress. Furthermore, cell membrane integrity was damaged at 2 °C in the mango leaf, as shown by the content of malondialdehyde (MDA), and eight MiCNGCs are positively correlated with MDA contents. The high correlation between MiCNGCs and MDA implies MiCNGCs might regulate cell membrane integrity by regulating MDA content. Together, these findings provide a valuable guideline for the functional characterization of CNGC genes and will benefit future studies related to cold stress and calcium transport in mango
Hormesis Responses of Growth and Photosynthetic Characteristics in <i>Lonicera japonica</i> Thunb. to Cadmium Stress: Whether Electric Field Can Improve or Not?
“Hormesis” is considered a dose–response phenomenon mainly observed at hyperaccumulator plants under heavy metals stress. In this study, the effects of electric fields on hormesis responses in Lonicera japonica Thunb. under cadmium (Cd) treatments were investigated by assessing the plant growth and photosynthetic characteristics. Under Cd treatments without electric fields, the parameters of plant growth and photosynthetic characteristics increased significantly when exposed to 5 mg L−1 Cd, and decreased slightly when exposed to 25 mg L−1 Cd, showing an inverted U-shaped trend, which confirmed that low concentration Cd has a hormesis effect on L. japonica. Under electric fields, different voltages significantly promoted the inverted U-shaped trend of the hormesis effect on the plant, especially by 2 V cm−1 voltage. Under 2 V cm−1 voltage, the dry weight of the root and leaf biomass exposed to 5 mg L−1 Cd increased significantly by 38.38% and 42.14%, and the photosynthetic pigment contents and photosynthetic parameters were also increased significantly relative to the control, indicating that a suitable electric field provides better improvements for the hormesis responses of the plant under Cd treatments. The synergistic benefits of the 5 mg L−1 Cd and 2 V cm−1 electric field in terms of the enhanced hormesis responses of growth and photosynthetic characteristics could contribute to the promoted application of electro-phytotechnology
Cytogenetic maps of homoeologous chromosomes A h01 and D h01 and their integration with the genome assembly in Gossypium hirsutum
Volume: 11Start Page: 405End Page: 42