Over-expression of glutamine synthetase genes Gln1-3/Gln1-4 improved nitrogen assimilation and maize yields

In agriculture, certain fertilizers that contain nitrogen generally tend to provide the most macronutrients for plant growth and development. The cDNAs of Gln1-3 and Gln1-4 genes, encoding glutamine synthetase isoenzymes (GS1), were fused to the rice actin1 promoter and over-expressed in the inbred maize line DH9632 by Agrobacte¬rium-mediated genetic transformation. PCR assays demonstrated the integration of these genes in six transgenic lines. Transcription of Gln1-3 or Gln1-4 in the transformants was also confirmed by semi-quantitative RT-PCR and qRT-PCR; the transgenic lines had significantly higher expression compared with wild type. Transgenic lines L2 and L7 expressed the most Gln1-3 and Gln1-4 mRNA, respectively, and had the most enzyme activity in leaves below the ear after pollination for 14 days. Over-expression of these two genes led to increased chlorophyll con¬tent and improved photosynthesis after 14 days. In addition, yield-related traits such as ear length, ear diameter, ear weight, grain weight per ear, and hundred-kernel weight were improved in the transgenic lines. The plot yield of transgenic L2 was increased by approximately 20%. These results suggest that overexpression of Gln1-3 and Gln1-4 in maize improves yields and enhances nitrogen using efficiency. Thus, transgenic lines overexpressing Gln1-3 or Gln1-4 in maize could potentially be used in maize breeding

Structural variation and introgression from wild populations in East Asian cattle genomes confer adaptation to local environment

BACKGROUND: Structural variations (SVs) in individual genomes are major determinants of complex traits, including adaptability to environmental variables. The Mongolian and Hainan cattle breeds in East Asia are of taurine and indicine origins that have evolved to adapt to cold and hot environments, respectively. However, few studies have investigated SVs in East Asian cattle genomes and their roles in environmental adaptation, and little is known about adaptively introgressed SVs in East Asian cattle. RESULTS: In this study, we examine the roles of SVs in the climate adaptation of these two cattle lineages by generating highly contiguous chromosome-scale genome assemblies. Comparison of the two assemblies along with 18 Mongolian and Hainan cattle genomes obtained by long-read sequencing data provides a catalog of 123,898 nonredundant SVs. Several SVs detected from long reads are in exons of genes associated with epidermal differentiation, skin barrier, and bovine tuberculosis resistance. Functional investigations show that a 108-bp exonic insertion in SPN may affect the uptake of Mycobacterium tuberculosis by macrophages, which might contribute to the low susceptibility of Hainan cattle to bovine tuberculosis. Genotyping of 373 whole genomes from 39 breeds identifies 2610 SVs that are differentiated along a "north-south" gradient in China and overlap with 862 related genes that are enriched in pathways related to environmental adaptation. We identify 1457 Chinese indicine-stratified SVs that possibly originate from banteng and are frequent in Chinese indicine cattle. CONCLUSIONS: Our findings highlight the unique contribution of SVs in East Asian cattle to environmental adaptation and disease resistance

Effects of cancer-testis antigen, TFDP3, on cell cycle regulation and its mechanism in L-02 and HepG2 cell lines <i>in vitro</i>

<div><p>TFDP3, also be known as HCA661, was one of the cancer-testis antigens, which only expressed in human tissues. The recent researches about TFDP3 mostly focused on its ability to control the drug resistance and apoptosis of tumor cells. However, the role of TFDP3 in the progress of the cell cycle is rarely involved. In this study, we examined the expression of TFDP3 in human liver tissues firstly. After that, we detect the expression of TFDP3 at the RNA level and protein level in L-02 cell line and HepG2 cell line, and the location of TFDP3 was defined by immunofluorescence technique. Furthermore, we synchronized the cells to G1 phase, S phase and G2 phase, and arrested cell mitosis. The localization of TFDP3 and co-localization with E2F1 molecules in different phases of hepatocyte lines. Finally, TFDP3 gene knockout was performed on L-02 and HepG2 cell lines, and detected the new cell cycles by flow cytometry. The result showed that the expression of TFDP3 molecule is negative in normal liver tissue, but positive in immortalized human hepatocyte cell line, and the expression level is lower than in hepatocellular carcinoma cell line. The expression level of TFDP3 was in the dynamic change of L-02 and HepG2 cell lines, and was related to the phase transition. TFDP3 can bind to E2F1 molecule to form E2F/TFDP3 complex; and the localizations of TFDP3 and E2F1 molecules and the co-localization were different in different phases of cell cycle in the nucleus and cytoplasm, which indicated that the E2F/TFDP3 complex involved in the process of regulating the cell cycle. By knocking down the TFDP3 expression level in L-02 and HepG2 cell lines, the cell cycle would be arrested in S phase, which confirmed that TFDP3 can be a potential target for tumor therapy.</p></div

Expression of TFDP3 in L-02 and HepG2 cell lines in different phases of cell cycle.

<p>(A) L-02 and HepG2 cell lines were synchronized to G1, S, G2 and M phases through TdR method and nocodazole, and synchronization effect was measured by flow cytometry. The proportion of each phase was shown in the figure (Red number = G1 phase, Blue number = S phase, Green number = G2 phase). This experiment was repeated 5 times to count the proportion of cells in each cell after synchronized. It can be seen that the proportion of cells that are synchronized is about 50% or so. (B) The expression of TFDP3 protein in each phase of cell cycle in L-02 and HepG2 cell lines was detected by Western Blot. The result showed that in L-02 and HepG2 cell lines, TFDP3 was expressed in every phase of cell cycle, and the expression level is various in different phases. Moreover, the expression level in S phase was higher than the other phases (p_L-02 = 0.003<0.01; p_HepG2 = 0.007<0.01; n = 5). The results of immunofluorescence staining showed the localization of TFDP3 and E2F1 in different phases of cell cycle in L-02 cell line (C) and HepG2 cell line (D), which were examined by laser confocal scanning microscopy. In the figures, the images from the top to the bottom in turn showed the distribution of E2F1 and TFDP3 in normal untreated cells (8000×), G1 phase, S phase, G2 phase and late stage cells (20000×); from left to right in turn showed nucleus staining (DAPI), E2F1 (FITC tag), TFDP3 (Cy3 tag) and merge images. The red arrows indicate that the location of the E2F1 expressed in nucleus in telophase and G1 phase. The yellow arrows indicate that the E2F1 mainly expressed in cytoplasm in the G2 phase. The blue arrows indicate the expression of TFDP3 in nucleus in telophase. The green arrows indicate that TFDP3 mainly expressed in cytoplasm in S and G2 phase. The co-localization of TFDP3 and E2F1 was indicated by the white arrows.</p

Expression of TFDP3 on L-02 cells and HepG2 cells.

<p>(A) The expression of TFDP3 in SK-BR-3, L-02 and HepG2 cell lines in mRNA level was detected by quantitative RT-PCR. TFDP3 and GAPDH primer sequences were shown before. L-02 and HepG2 cell lines expressed TFDP3 at the RNA level, and the expression level of TFDP3 in L-02 cell line was lower than in HepG2 cell line. The expression of TFDP3 in SK-BR-3 cell line was negative. (B) The expression of TFDP3 in SK-BR-3 cells, L-02 cells and HepG2 cells detected by Western Blot, and the expression level of TFDP3 in L-02 cell line was lower than in HepG2 cell line. (C) Immunofluorescence staining was used to detect the localization and expression of TFDP3 in L-02 cells and HepG2 cells. TFDP3 molecules could locate only in cytoplasm (as in the cells in mitotic indicated by red arrow), or also locate in the nucleus (as in indicated by white arrow).</p

TFDP3 in human normal liver and hepatocellular carcinoma tissue expression.

<p>The figure shows the results of immunohistochemical staining of human normal liver (a,b), human hepatocellular carcinoma (c,d) and human testis tissue sections (e,f). Tissue sections were stained with anti-TFDP3 antibody and subjected to hematoxylin staining (a,c,e ×200 and b,d,f ×400). The expression of TFDP3 in human normal liver tissue was negative, while in human hepatocellular carcinoma tissue and testicular tissue TFDP3 molecule was stained in nucleus (as indicated by black arrow in the figure) into brown (high expression), and cytoplasm (indicated by blue arrow) into light brown (low expression).</p

Cell cycle changes of L-02 cell line and HepG2 cell line after TFDP3 knockdown.

<p>(A) The expression of TFDP3 in L-02 and HepG2 cell lines transfected with TFDP3-siRNA2 and TFDP3-siRNA3 was detected by Western Blot. (B) Flow cytometry was used to detect cell cycle changes in L-02 and HepG2 cell lines after TFDP3 knockdown (Red number = G1 phase, Blue number = S phase, Green number = G2 phase). It is clearly that the proportion of cells in G1 phase declined, and inclined in S phase.</p

Parkin promotes proteasomal degradation of p62: implication of selective vulnerability of neuronal cells in the pathogenesis of Parkinson's disease

Mutations or inactivation of parkin, an E3 ubiquitin ligase, are associated with familial form or sporadic Parkinson&#39;s disease (PD), respectively, which manifested with the selective vulnerability of neuronal cells in substantia nigra (SN) and striatum (STR) regions. However, the underlying molecular mechanism linking parkin with the etiology of PD remains elusive. Here we report that p62, a critical regulator for protein quality control, inclusion body formation, selective autophagy and diverse signaling pathways, is a new substrate of parkin. P62 levels were increased in the SN and STR regions, but not in other brain regions in parkin knockout mice. Parkin directly interacts with and ubiquitinates p62 at the K13 to promote proteasomal degradation of p62 even in the absence of ATG5. Pathogenic mutations, knockdown of parkin or mutation of p62 at K13 prevented the degradation of p62. We further showed that parkin deficiency mice have pronounced loss of tyrosine hydroxylase positive neurons and have worse performance in motor test when treated with 6-hydroxydopamine hydrochloride in aged mice. These results suggest that, in addition to their critical role in regulating autophagy, p62 are subjected to parkin mediated proteasomal degradation and implicate that the dysregulation of parkin/p62 axis may involve in the selective vulnerability of neuronal cells during the onset of PD pathogenesis