Molecular epidemiology of measles viruses in China, 1995–2003

This report describes the genetic characterization of 297 wild-type measles viruses that were isolated in 24 provinces of China between 1995 and 2003. Phylogenetic analysis of the N gene sequences showed that all of the isolates belonged to genotype H1 except 3 isolates, which were genotype A. The nucleotide sequence and predicted amino acid homologies of the 294-genotype H1 strains were 94.7%–100% and 93.3%–100%, respectively. The genotype H1 isolates were divided into 2 clusters, which differed by approximately 2.9% at the nucleotide level. Viruses from both clusters were distributed throughout China with no apparent geographic restriction and multiple co-circulating lineages were present in many provinces. Even though other measles genotypes have been detected in countries that border China, this report shows that genotype H1 is widely distributed throughout the country and that China has a single, endemic genotype. This important baseline data will help to monitor the progress of measles control in China

Organ Mass Variation in a Toad Headed Lizard <i>Phrynocephalus vlangalii</i> in Response to Hypoxia and Low Temperature in the Qinghai-Tibet Plateau, China

<div><p>Hypoxia and low temperature at high altitudes are the main environmental pressures for alpine animals, inducing phenotypic plasticity at several levels. To investigate the effect of these variables on the organ mass of <i>Phrynocephalus vlangalii</i>, 138 individuals belonging to four populations living along an altitudinal gradient in the Qinghai-Tibet Plateau (China) were dissected to remove heart, lungs, stomach, and intestinal tract. Organ dry mass, individuals’ sex, and body mass, as well as mean annual temperature and average air pressure (calculated from a 30-year-data series obtained from the National Climatic Data Center) were subjected to two-way analyses of covariance and generalized linear mixed models (GLMMs). Except for the heart, organ mass varied significantly among populations, although only lung and stomach mass increased significantly with increasing altitude. Males’ heart and lung mass was higher than that of females, which might be due to their different behavior and reproductive efforts. GLMM analyses indicated that air pressure had a positive effect on heart, lung and intestinal tract mass, whereas temperature had a negative effect on these three organs. In order to explain the effect of hypoxia and low temperature on <i>P</i>. <i>vlangalii</i>’s organ mass, further rigorous study on respiration, energy budget and food intake was encouraged.</p></div

Spermidine Enhances Heat Tolerance of Rice Seeds by Modulating Endogenous Starch and Polyamine Metabolism

Polyamines have been reported to be involved in grain filling and they might contribute to the construction of heat resistance of some cereals. In this study, the hybrid rice &#8216;YLY 689&#8217; was used to explore the possible effects of exogenous spermidine (Spd) on seed quality under high temperature during the filling stage. Rice spikes were treated with Spd or its synthesis inhibitor cyclohexylamine (CHA) after pollination, and then the rice plants were transferred to 40 &#176;C for 5-day heat treatment. The results showed that, compared with the control under high temperature, Spd pretreatment significantly improved the germination percentage, germination index, vigor index, seedling shoot height, and dry weight of seeds harvested at 35 days after pollination, while the CHA significantly decreased the seed germination and seedling growth. Meanwhile, Spd significantly increased the peroxidase (POD) activity and decreased the malondialdehyde (MDA) content in seeds. In addition, after spraying with Spd, the endogenous content of spermidine and spermine and the expression of their synthetic genes, spermidine synthase (SPDSYN) and spermine synthase (SPMS1 and SPMS2), significantly increased, whereas the accumulation of amylose and total starch and the expression of their related synthase genes, soluble starch synthase II-3 (SS II-3) and granules bound starch synthase I (GBSSI), also increased to some extent. The data suggests that exogenous Spd pretreatment could alleviate the negative impacts of high temperature stress on rice seed grain filling and improve the rice seed quality to some extent, which might be partly caused by up-regulating endogenous polyamines and starch metabolism

Effects of altitude and sex on organ mass in <i>Phrynocephalus vlangalii</i>.

<p>Effects of altitude and sex on organ mass in <i>Phrynocephalus vlangalii</i>.</p

Influence of low temperature and hypoxia on <i>Phrynocephalus vlangalii</i> organ mass, based on generalized linear mixed models.

<p>Influence of low temperature and hypoxia on <i>Phrynocephalus vlangalii</i> organ mass, based on generalized linear mixed models.</p

Altitudinal variation of <i>Phrynocephalus vlangalii</i> organ mass in the Qinghai-Tibet Plateau, China.

<p>(A) heart, (B) lung, (C) stomach, (D) intestinal tract. The effect of body mass was eliminated using the unstandardized residuals obtained from the linear regression analysis performed for each organ. Black squares and empty circles represent the means for males and females, respectively, and the error bar represents the standard error. The solid and dotted lines represent the fitting of organ mass to altitude for males and females, respectively. The coefficients of the linear regression analysis are displayed above lines and the asterisk (*) denotes <i>P</i> < 0.05.</p

Altitude and climatic factors in the four sampling locations of <i>Phrynocephalus vlangalii</i> within the Qinghai-Tibet Plateau (China) and the several phenotypic variables considered in the present study.

<p>Altitude and climatic factors in the four sampling locations of <i>Phrynocephalus vlangalii</i> within the Qinghai-Tibet Plateau (China) and the several phenotypic variables considered in the present study.</p

Genetic characterization of the hemagglutinin genes of wild-type measles virus circulating in china, 1993-2009.

BACKGROUND: China experienced several large measles outbreaks in the past two decades, and a series of enhanced control measures were implemented to achieve the goal of measles elimination. Molecular epidemiologic surveillance of wild-type measles viruses (MeV) provides valuable information about the viral transmission patterns. Since 1993, virologic surveillnace has confirmed that a single endemic genotype H1 viruses have been predominantly circulating in China. A component of molecular surveillance is to monitor the genetic characteristics of the hemagglutinin (H) gene of MeV, the major target for virus neutralizing antibodies. PRINCIPAL FINDINGS: Analysis of the sequences of the complete H gene from 56 representative wild-type MeV strains circulating in China during 1993-2009 showed that the H gene sequences were clustered into 2 groups, cluster 1 and cluster 2. Cluster1 strains were the most frequently detected cluster and had a widespread distribution in China after 2000. The predicted amino acid sequences of the H protein were relatively conserved at most of the functionally significant amino acid positions. However, most of the genotype H1 cluster1 viruses had an amino acid substitution (Ser240Asn), which removed a predicted N-linked glycosylation site. In addition, the substitution of Pro397Leu in the hemagglutinin noose epitope (HNE) was identified in 23 of 56 strains. The evolutionary rate of the H gene of the genotype H1 viruses was estimated to be approximately 0.76×10(-3) substitutions per site per year, and the ratio of dN to dS (dN/dS) was <1 indicating the absence of selective pressure. CONCLUSIONS: Although H genes of the genotype H1 strains were conserved and not subjected to selective pressure, several amino acid substitutions were observed in functionally important positions. Therefore the antigenic and genetic properties of H genes of wild-type MeVs should be monitored as part of routine molecular surveillance for measles in China