Biotechnology Letters - The transport of citrate from the mitochondria to the cytoplasm is essential during lipid accumulation. This study aimed to explore the role of mitochondrial... 相似文献
<正>Plasmids are useful tools for studying genetic information in living cells,as well as heterologous expression of genes and pathways in cells (Lauritsen et al.,2018).Various methods have been developed for plasmid manipulation both in vivo and in vitro(Aslanidis and de Jong,1990;Li and Elledge,2007;Xia et al.,2018).However,large plasmids,such as P1-based artificial chromosomes (PACs),bacterial artificial chromosomes (BACs),and fosmids, 相似文献
Osteoporosis is one of the leading disorders among aged people. Bone loss results from a number of physiological alterations, such as estrogen decline and aging. Meanwhile, iron overload has been recognized as a risk factor for bone loss. Systemic iron homeostasis is fundamentally governed by the hepcidin–ferroportin regulatory axis, where hepcidin is the key regulator. Hepcidin deficiency could induce a few disorders, of which iron overload is the most representative phenotype. However, there was little investigation of the effects of hepcidin deficiency on bone metabolism. To this end, hepcidin-deficient (Hamp1−/−) mice were employed to address this issue. Our results revealed that significant iron overload was induced in Hamp1−/− mice. Importantly, significant decreases of maximal loading and maximal bending stress were found in Hamp1−/− mice relative to wildtype (WT) mice. Moreover, the levels of the C-telopeptide of type I collagen (CTX-1) increased in Hamp1−/− mice. Therefore, hepcidin deficiency resulted in a marked reduction of bone load-bearing capacity likely through enhancing bone resorption, suggesting a direct correlation between hepcidin deficiency and bone loss. Targeting hepcidin or the pathway it modulates may thus represent a therapeutic for osteopenia or osteoporosis. 相似文献
Centromeres are composed of long arrays of satellite repeats in most multicellular eukaryotes investigated to date. The satellite repeat–based centromeres are believed to have evolved from “neocentromeres” that originally contained only single- or low-copy sequences. However, the emergence and evolution of the satellite repeats in centromeres has been elusive. Potato (Solanum tuberosum) provides a model system for studying centromere evolution because each of its 12 centromeres contains distinct DNA sequences, allowing comparative analysis of homoeologous centromeres from related species. We conducted genome-wide analysis of the centromeric sequences in Solanum verrucosum, a wild species closely related to potato. Unambiguous homoeologous centromeric sequences were detected in only a single centromere (Cen9) between the two species. Four centromeres (Cen2, Cen4, Cen7, and Cen10) in S. verrucosum contained distinct satellite repeats that were amplified from retrotransposon-related sequences. Strikingly, the same four centromeres in potato contain either different satellite repeats (Cen2 and Cen7) or exclusively single- and low-copy sequences (Cen4 and Cen10). Our sequence comparison of five homoeologous centromeres in two Solanum species reveals rapid divergence of centromeric sequences among closely related species. We propose that centromeric satellite repeats undergo boom-bust cycles before a favorable repeat is fixed in the population. 相似文献
The effect of Mn and NaCl on growth, mineral nutrients and antioxidative enzymes in two tetroploid wheat genotypes differing in salt tolerance was investigated in this study. 100 mM NaCl and Mn stress significantly inhibited plant growth, photosynthesis and Ca uptake, while stimulated ROS accumulation, MDA and proline content in wheat plants, Mn stress also increased SOD, APX, GR and DHAR activities. Durum wheat (AS780) was less affected by 100 mM NaCl and Mn stress than emmer wheat (AS847) due to more proline production, higher antioxidative enzymes activities and less-affected mineral nutrients. Application of 10 mM NaCl to Mn-stressed durum wheat alleviated Mn-induced damage by reducing Mn accumulation and translocation, while promoting proline accumulation and SOD, APX and GR activities. Irrespective of NaCl level, the combined stress of Mn and NaCl caused more severe oxidative stress, result in further reduction of photosynthetic rate and plant growth in emmer wheat as compared to Mn stress alone. The additively negative effects of NaCl and Mn stress on growth of emmer wheat results from reduced SOD and APX activities as well as Ca, Cu and Fe accumulation in both shoots and roots. These results suggest that salt-tolerant durum wheat is superior to emmer in adapting to Mn stress and the combined stress of salinity and Mn.
For the specificity of prostate cancer markers, prostate specific antigen (PSA) has been widely used in prostate cancer screening, diagnosis, and treatment after monitoring. In normal male serum, PSA can only be detected in traces of 0-4 ng mL(-1). In this paper, we constructed an electrochemical immunosensor for PSA detection using a nanocomposite film of graphene sheets-methylene blue-chitosan (GS-MB-CS) as electrode material. The nanocomposite film showed high binding affinity to the electrode and was used to immobilize the antibody of PSA. The modification procedure was monitored by cyclic voltammetry (CV). An amperometric biosensor was easily developed based on the response of peak current to the capture of PSA induced by specific antigen-antibody reactions. Under optimum conditions, the amperometric signal decreased linearly with PSA concentration (0.05-5.00 ng mL(-1)). A low limit of detection (13 pg mL(-1)) and a high selectivity are obtained. Moreover, the prepared immunosensor was applied for the analysis of PSA in serum samples with satisfactory results. The proposed method may have a promising future in biochemical assays for high selectivity, good reproducibility, and stability. 相似文献
A codon optimized mature human β-defensin-3 gene (smHBD3) was synthesized and fused with TrxA to construct pET32-smHBD3 vector, which was transformed into
E. coli BL21(DE3) and cultured in MBL medium. The volumetric productivity of fusion protein reached 0.99 g fusion protein l−1, i.e. 0.21 g mature HBD3 l−1. Ninety-six percentage of the fusion protein was in a soluble form and constituted about 45% of the total soluble protein.
After cell disruption, the soluble fusion protein was separated by affinity chromatography and cleaved by enterokinase, and
then the mature HBD3 was purified by cationic ion exchange chromatography. The overall recovery ratio of HBD3 was 43%. The
purified mature HBD3 demonstrated antimicrobial activity against E. coli.
Revisions requested 13 December 2005; Revisions received 24 January 2006 相似文献