[Correlation of lifelong premature ejaculation with 5-HT system gene polymorphism].

Premature ejaculation is one of the common male sexual dysfunction diseases. Lifelong premature ejaculation (LPE), characterized by an early onset and a long course of disease, has a variety of negative effects on men. The pathogenesis of LPE has not been clarified, but it is believed to be related to the regulation of 5-HT and the 5-HT1a and 5-HT2c receptors from the perspective of the theory of 5-HT system neurotransmitter disorder. Current studies indicate that the 5-HT transporter gene-linked polymorphic region (5-HTTLPR), 5-HT1a receptor gene polymorphism and 5-HT2c receptor gene polymorphism may be associated with the development of and drug effect on LPE. This article reviews the current studies on the development of LPE, effects of medication and 5-HT system gene polymorphism, and discusses the correlation of 5-HT system gene polymorphism with the development of LPE and effects of medication.

Arabidopsis cyclic nucleotide-gated channel 6 is negatively modulated by multiple calmodulin isoforms during heat shock.

An increased concentration of cytosolic Ca2+ is an early response of plant cells to heat shock. Arabidopsis cyclic nucleotide-gated ion channel 6 (CNGC6) mediates heat-induced Ca2+ influx and is activated by cAMP. However, it remains unclear how the Ca2+ conductivity of CNGC6 is negatively regulated under the elevated cytosolic Ca2+ concentration. In this study, Arabidopsis calmodulin isoforms CaM1/4, CaM2/3/5, CaM6, and CaM7 were found to bind to CNGC6 to varying degrees, and this binding was dependent on the presence of Ca2+ and IQ6, an atypical isoleucine-glutamine motif in CNGC6. Knockout of CaM2, CaM3, CaM5, and CaM7 genes led to a marked increase in plasma membrane inward Ca2+ current under heat shock conditions; however, knockout of CaM1, CaM4, and CaM6 genes had no significant effect on plasma membrane Ca2+ current. Moreover, the deletion of IQ6 from CNGC6 led to a marked increase in plasma membrane Ca2+ current under heat shock conditions. Taken together, the data suggest that CNGC6-mediated Ca2+ influx is likely to be negatively regulated by CaM2/3/5 and CaM7 isoforms under heat shock conditions, and that IQ6 plays an important role in CaM binding and the feedback regulation of the channel.

Molecular genetic mechanisms of interaction between host plants and pathogens.

In recent years, a great number of plant resistance (R) genes and pathogen avirulence (Avr) genes were identified. Exciting breakthroughs were also made on the structural and functional analysis of R proteins and Avr proteins, and the mechanistic interaction between them. Plants have evolved two layers of the immune system to cope with pathogens in the evolutionary processes, which are pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI). In PTI responses, conserved PAMPs are recognized by plant plasma membrane-localized pattern recognition receptors (PRRs) and disease resistance is activated. Furthermore, the ETI immune signaling is activated by the recognition of pathogen Avr proteins by the host R proteins, which usually results in hypersensitive responses at the infection site. In this review, we summarize the progresses on PTI and ETI, and discuss the genetic mechanism of the interaction between plant R gene and pathogen Avr gene in detail. We also envision the new challenges and propose the new strategies for the future investigations on plant resistance molecular breeding.

[Mapping and cloning of GAD1-2 for long awn using CSSLs in rice (Oryza sativa L.)].

Rice is an important food crop in the world. The awn may protect rice seeds from being cut by birds, which is important in rice domestication, survival and diffusion. However, the characteristic of awn is gradually washed out during rice domestication and artificial selection. Mapping and cloning of rice awn genes is the basis of studying the genetic mechanism of awn domestication. In this study, 146 chromosome segment substitution lines (CSSLs) derived from DongNanHui 810/ZhangPu wild rice with DongNanHui 810 as the recurrent parent were used to analyze the quantitative trait loci (QTL) controlling the long awn of rice. The results showed that four CSSLs contained one QTL for the long awn. Using substitution mapping, the GAD1-2 gene was mapped between two markers (Ind8-10 and RM4936) on chromosome 8, with a genetic distance of about 4.75 Mb. Using the dominant individuals of segregating populations, the GAD1-2 gene was eventually located between two Indel markers, with a physical distance of about 27 kb, which contained only two candidate genes Os08g0485500 and Os08g0485400. Sequencing analysis showed that Os08g0485500 was the candidate gene of GAD1-2. Further analysis showed that there were six bases missing in the conservative ORF region, resulting in the absence of serine and cysteine that led to the long awn of the four CSSLs. The GAD1 gene was also cloned in this position, suggesting that GAD1-2 and GAD1 were allelic. This study laid a foundation for further understanding of the genetic regulation mechanism and genetic evolution of the awn gene in rice.

[Morphological characteristics and gene mapping of a palea degradation(pd2) mutant in rice].

The yield and quality of rice are directly impacted by floral organ development in rice. Understanding of the floral development mechanism will be useful in genetic improvement of yield and quality. In this study, a rice mutant palea degradation 2 (pd2) in an indica cultivar '8PW33' was obtained after 60Co γ-ray treatment. Analysis of the mutant showed that, compared to the wild type, plant height, total grain number per panicle, and sword leaf width were significantly increased, but the seed setting rate were significantly decreased. The florets of the mutant exhibited degraded palea and sickle-shaped tortuous lemma. Detail examination using scanning electron microscopy revealed that when epidermis of the vane and lemma were normal, epidermis of the palea were arranged tightly, which might result from degraded palea. Genetic analysis supported that this mutation phenotype was controlled by a single recessive gene. Polymorphic analysis of simple sequence repeat markers demonstrated that PD2 gene is located on chromosome 9. With a larger mapping population and more indel markers, we further mapped PD2 gene between 2 indel markers with a physical region of about 82 kb. Within this region, there is a cloned gene REP1 known to control rice palea development. By comparing the DNA sequences of REP1 from pd2 and 8PW33, in combination with the results of phenotypic analysis, we concluded that PD2 is an allele of REP1.

[Substitution mapping of QTL for panicle exertion using CSSL in rice (Oryza sativa L.)].

Panicle exertion, the distance between the leaf cushion of flag and the neck-panicle node, is an important morphological trait, which has significant impact on hybrid seed production of rice. In this study, 94 chromosome segment substitution lines (CSSL), derived from 9311/Nipponbare with 9311 as the recurrent parent, were used to analyze quantitative trait loci (QTL) controlling the panicle exertion. The results showed that 17 CSSL contained QTL for the panicle exertion. Using substitution mapping, 8 QTLs were mapped on rice chromosomes 2, 3, 7, 8, 9, and 11, respectively. The QTL additive effect ranged from 0.10 to 3.20, and the additive effects of qPE-9 and qPE-11 were 3.15 and 2.95, respectively, showing the feature of a major gene. In addition, qPE-2-2, qPE-3-1, qPE-3-2, qPE-7, and qPE-8 were mapped in a marker interval less than 10.0 cM. Mapping of the QTL has laid a foundation for improving the panicle exertion with marker-assisted selection and cloning of the QTL in rice.

[Simulation on area threshold of urban building land based on water environmental response in watersheds.] / 基于流域水环境响应的城市建设用地面积阈值模拟.

Urban sprawl has impacted increasingly on water environment quality in watersheds. Based on water environmental response, the simulation and prediction of expanding threshold of urban building land could provide an alternative reference for urban construction planning. Taking three watersheds (i.e., Yundang Lake at complete urbanization phase, Maluan Bay at peri-urbanization phase and Xinglin Bay at early urbanization phase) with 2009-2012 observation data as example, we calculated the upper limit of TN and TP capacity in three watersheds and identified the threshold value of urban building land in watersheds using the regional nutrient management (ReNuMa) model, and also predicted the water environmental effects associated with the changes of urban landscape pattern. Results indicated that the upper limit value of TN was 12900, 42800 and 43120 kg, while that of TP was 340, 420 and 450 kg for Yundang, Maluan and Xinglin watershed, respectively. In reality, the environment capacity of pollutants in Yundang Lake was not yet satura-ted, and annual pollutant loads in Maluan Bay and Xinglin Bay were close to the upper limit. How-ever, an obvious upward trend of annual TN and TP loads was observed in Xinglin Bay. The annual pollutant load was not beyond the annual upper limit in three watersheds under Scenario 1, while performed oppositely under Scenario 3. Under Scenario 2, the annual pollutant load in Yundang Lake was under-saturation, and the TN and TP in Maluan Bay were over their limits. The area thresholds of urban building land were 1320, 5600 and 4750 hm2 in Yundang Lake, Maluan Bay and Xinglin Bay, respectively. This study could benefit the regulation on urban landscape planning.