ABSTRACT
In this study, the fatty acid desaturase gene FAD2 was cloned from Coix lacryma-jobi L. and its molecular structure and function were studied. The results showed that the full-length cDNA sequence of FAD2 gene was 936 bp encoding 311 amino acid residues. Bioinformatics prediction results showed that the protein encoded by the FAD2 gene was an alkaline hydrophilic unstable protein with a molecular weight of 34.87 kDa. It contained three transmembrane helix domain, and did not contain the signal peptide splicing site, and was most likely to be located in plasmid membrane. Compared with other similar genes in plants, it has only a histidine conserved site, His Box Ⅲ histidine site (HXXHH), suggesting its activity may be reduced. Phylogenetic tree analysis showed that FAD2 was closely related to monocotyledonous plants, especially Maize and Oryza sativa japonica Group, but farther from dicotyledonous plants. Therefore, it was inferred that FAD2 might have similar functions with similar genes in Maize and Oryza sativa japonica Group. In addition, the expression of FAD2 gene could be detected in Coix lacryma-jobi L. with high oil content, but not in low oil content of Coix lacryma-jobi L. In order to clarify the function of FAD2, the gene was heterologously expressed in sporomyces cerevisiae. The results showed that the protein encoded by FAD2 gene did not catalyze the formation of C18∶1 unsaturated fatty acid into C18∶2 unsaturated fatty acid. Therefore, it was speculated that the deletion of histidinine conserved site of FAD2 gene might lead to the decrease of protein activity or even inactivation. This study provides reference value for further understanding the molecular structure characteristics of fatty acid desaturase. At the same time, it laid a foundation for elucidating the biosynthetic pathway of Coix lacryma-jobi L.
ABSTRACT
As a key gene in the regulation of long-chain fatty acid biosynthesis, 3-ketoacyl-CoA synthase (KCS) plays an important role in the growth and development of Coix lacryma-jobi L. In this study, the KCS gene was cloned from cDNA of Coix lachryma-Jobi L. and bioinformatics analysis was performed. Results showed that the full length KCS gene was 1 548 bp encoding 515 amino acids. Bioinformatics analysis indicated that the gene encoded a 58 608.12 Da protein with an isoelectric point of 9.20 containing two transmembrane helical structure domains and lacking a signal peptide, with a likely subcellular localization in main plastid membranes. The results of multiple sequence comparisons and evolutionary tree analysis revealed that KCS had three identical conserved sequences and was closely related to KCS from monocotyledons such as Sorghum bicolor, Zea mays, Setaria italica, Panicum miliaceum, Oryza brachyantha, Hordeum vulgare, Aegilops tauschii subsp. Tauschii. We speculated that the evolution of the gene was similar among these plants of the same family. In addition, gene expression analysis showed that the KCS gene was significantly different in Coix lacryma-jobi L. isolates having different lipid content. This work will facilitate further study of the regulatory mechanism of this enzyme in fatty acid synthesis.
ABSTRACT
The pre-Bötzinger complex (pre-BötC) residing in the ventrolateral medulla oblongata, is thought to be the kernel of respiratory rhythmogenesis. Episodic hypoxia exerts respiratory long-term facilitation, being recognized as electrophysiological characteristic of respiratory motor neuroplasticity. Our previous study demonstrated up-regulated expression of phospho-protein kinase C θ (P-PKCθ) in the pre-BötC of rats receiving chronic intermittent hypoxic (CIH) challenge. The present study was aimed to examine subcellular distribution of P-PKC substrates (P-PKCsub) and explore PKC down-stream targeting proteins in the pre-BötC in normoxic and CIH rats. Using neurokinin-1 receptor (NK1R) as a marker of the pre-BötC, P-PKCsub immunoreactivity was revealed by immunofluorescence and immuno-electron microscopic double-labeling in the pre-BötC. Western blot was applied to analyze P-PKCsub proteins in ventrolateral medulla, containing the pre-BötC. The results showed that NK1R immunoreactivity (NK1R-ir) was expressed mainly along plasma membranes of somata and processes, outlining pre-BötC neurons under the light microscope. P-PKCsub immunoreactive (P-PKCsub-ir) fluorophores in dot-like appearance appeared in somata and processes. Some were in close apposition to plasma membranes. A majority of P-PKCsub-ir neurons was found with NK1R-ir. CIH challenge up-regulated the expression of P-PKCsub proteins in the ventrolateral medulla. Under the electron microscope, NK1R-ir product was found to distribute along the inner membrane surfaces of somata and dendrites. P-PKCsub-ir gold particles were located in somata and dendrites, and some were distributed along the inner membrane surfaces, as well as in the endoplasmic reticulum and postsynaptic dense body. These results suggest that CIH challenge up-regulates the expression of P-PKCsub proteins, probably including some receptor proteins in the postsynaptic membrane, which may contribute to respiratory neuroplasticity via activation of PKCθ in the pre-BötC.
Subject(s)
Animals , Rats , Hypoxia , Medulla Oblongata/metabolism , Neurons/metabolism , Rats, Sprague-Dawley , Receptors, Neurokinin-1/metabolismABSTRACT
The paper dilates upon epileptic EEG data treatment and analysis methods based on machine learning,including supervised learning,unsupervised learning,semi-supervised learning,reinforcement learning and machine learning methods of other types,and evaluates the application effects of the methods on inspection of epileptic EEG data.
ABSTRACT
<p><b>OBJECTIVE</b>To develop an HPLC method for content determination of dehydroabietic acid and abietic acid in aqueous alkali extract of Liquidambaris Resina.</p><p><b>METHOD</b>The determination was carried out on a DIONEX C18 column (4.6 mm x 250 mm, 5 microm) eluted with acetonitrile and water containing 0.1% acetic acid. The flow rate was 1 mL x min(-1), and the detected wavelength was set at 210, 240 nm.</p><p><b>RESULT</b>The peak areas and the sample quantity of the two components had good linear relationship in the range of 0.4-3.4 microg for dehydroabietic acid, and 0.6-4.8 microg for abietic acid. The average recoveries were 99.53%, 101.9%, respectively.</p><p><b>CONCLUSION</b>The method was proved to be simple, accurate and used for the quality evaluation of Liquidambaris Resina.</p>