M-current plays an important role in the regulation of neuronal excitability and stabilizing the membrane potential. KCNQ2 and KCNQ3 potassium ion channels are proposed to underlie the neuronal M-current. In this paper, we studied the permeable properties and the selective properties of the KCNQ2/3 potassium channel with molecular biology and electrophysiology methods, respectively. Then, based on the first principle and the structure of the KCNQ2/3 potassium ion channel, the potential curve is calculated by the density functional theory. And forced by the potential, the dynamical properties of KCNQ2/3 channels are also studied. Our results, not only from electrophysiology study but also stochastic dynamics simulations, indicate that heteromeric KCNQ2/3 channels all showed a permeation sequence of K+ >Rb+>>Na+. The aim of this research is looking for a possible physical basis for the permeation of ion channel and opens an avenue for further research.

Further dissection of physiological molecular mechanisms is indispensable to alleviate rice yield losses resulting from cold injury. By using 105 near-isogenic lines (NILs) derived from a backcross between cv. Lijiangxintuanheigu (LTH) and cv. Towada, we detected quantitative trait loci (QTLs) for physiological traits of the rice flag leaf, based on polymorphic simple sequence repeat (SSR) markers, inclusive composite interval mapping (ICIM), mixed composite interval mapping (MCIM) approaches and phenotypic value subjected to combine with cold-water stress and three nitrogen application rates. By using ICIM, a total of 34 QTLs with additive effects (A-QTLs) were identified on chromosomes 1, 3, 4, 5, 6, 7 and 10, and the phenotypic variation (R²) explained by each QTL ranged from 8.46 to 29.14%. By using MCIM, 20 A-QTLs and 14 pairs of QTLs with epistatic × environment interaction effects (Epistatic QTLs) were detected, the contribution of environment interaction (H²AE) was 0.87 to 7.36%, while the contribution rates of E-QTL were from 0.97 to 3.58%. Fourteen A-QTLs were detected by ICIM and MCIM, which may serve as a basis for fine-mapping and candidate gene studies, and providing strategies for the development of cold-tolerant rice cultivars and nitrogen application to alleviate chilling stress.

Chilling damage significantly reduces grain yield in rice, while exploring major quantitative trait loci (QTLs) has the potential to improve rice production. Mapping of QTLs for 5 cold tolerance-related traits at the booting stage was conducted with SSR markers and inclusive composite interval mapping (ICIM) approach, based on 105 near-isogenic lines derived from a backcross between Lijiangxintuanheigu (LTH, cold-tolerant landrace) and Towada (cold-sensitive cultivar). Phenotype values were investigated under five cold-stress environments and analysed by the best linear unbiased prediction (BLUP). Twenty-one QTLs were identified on chromosomes 1, 2, 3, 4, 6, 7, 10 and 11, and the amount of variation (R²) explained by each QTL ranged from 7.71 to 29.66%, with five co-located QTL regions. Eight novel major loci (qSF-2, qSF-6a, qSF-7, qGW-6, qDGWP-4, qDSWPP-4, qDWPP-1 and qDWPP-4b) were detected in several environments and BLUP, and their alleles were contributed by LTH with R²variance from 12.24 to 29.66%. These favourable QTLs would facilitate elucidation of the genetic mechanism of cold tolerance and provide strategies for breeding high-productive rice.

Hyperhomocysteinemia (HHcy) causes cardiovascular dysfunction during pregnancy. We have previously shown that HHcy disrupts the regulation of O2 consumption in the heart by lowering NO bioavailability through the generation of superoxide. Presently, we explored the molecular effects of HHcy during pregnancy. Pregnant SD rats were fed with 10g/L methionine in drinking water for 20 days to increase plasma homocysteine (Hcy) (3.0±1.2 to 14.6±8.9 uM). mRNA microarray analysis of left ventricle tissue revealed significant changes in 242 genes (p<0.05, > ±1.5). We grouped differentially expressed genes into different functional categories, and the results showed a wide range of distribution of expression patterns within the functional groups. For example, some cell structure/motility genes were upregulated, including Kruppel‐like factor, histone deacetylase 1, myosin 1b, and ARP2 actin‐related protein 2. We have also seen several oxidative stress‐related genes, such as hypoxia up‐regulated 1 and ischemia related factor up‐regulated. Metabolism genes such as pyruvate dehydrogenase phosphatase isoenzyme 2 and fatty acid transporter 4 were differentially regulated.ConclusionHHcy triggers cardiac gene expression changes during pregnancy, suggesting an underlying mechanism behind the effects of HHcy.