Evidence for Inbreeding and Genetic Differentiation among Geographic Populations of the Saprophytic Mushroom Trogia venenata from Southwestern China

During the past 40 years, more than 400 Sudden Unexplained Deaths (SUDs) have occurred in Yunnan, southwestern China. Epidemiological and toxicological analyses suggested that a newly discovered mushroom called Trogia venenata was the leading culprit for SUDs. At present, relatively little is known about the genetics and natural history of this mushroom. In this study, we analyzed the sequence variation at four DNA fragments among 232 fruiting bodies of T. venenata collected from seven locations. Our ITS sequence analyses confirmed that all the isolates belonged to the same species. The widespread presence of sequence heterozygosity within many strains at each of three protein-coding genes suggested that the fruiting bodies were diploid, dikaryotic or heterokaryotic. Within individual geographic populations, we found significant deviations of genotype frequencies from Hardy-Weinberg expectations, with the overall observed heterozygosity lower than that expected under random mating, consistent with prevalent inbreeding within local populations. The geographic populations were overall genetically differentiated. Interestingly, while a positive correlation was found between population genetic distance and geographic distance, there was little correlation between genetic distance and barium concentration difference for the geographic populations. Our results suggest frequent inbreeding, geographic structuring, and limited gene flow among geographic populations of T. venenata from southwestern China.     

OGR1/GPR68 Modulates the Severity of Experimental Autoimmune Encephalomyelitis and Regulates Nitric Oxide Production by Macrophages

Ovarian cancer G protein-coupled receptor 1 (OGR1) is a proton-sensing molecule that can detect decreases in extracellular pH that occur during inflammation. Although OGR1 has been shown to have pro-inflammatory functions in various diseases, its role in autoimmunity has not been examined. We therefore sought to determine whether OGR1 has a role in the development of T cell autoimmunity by contrasting the development of experimental autoimmune encephalomyelitis between wild type and OGR1-knockout mice. OGR1-knockout mice showed a drastically attenuated clinical course of disease that was associated with a profound reduction in the expansion of myelin oligodendrocyte glycoprotein 35-55-reactive T helper 1 (Th1) and Th17 cells in the periphery and a reduced accumulation of Th1 and Th17 effectors in the central nervous system. We determined that these impaired T cell responses in OGR1-knockout mice associated with a reduced frequency and number of dendritic cells in draining lymph nodes during EAE and a higher production of nitric oxide by macrophages. Our studies suggest that OGR1 plays a key role in regulating T cell responses during autoimmunity.     

Assessing the importance of a self-generated detachment process in river biofilm models

1. Epilithic biofilm biomass was measured for 14 months in two sites, located up‐ and downstream of the city of Toulouse in the Garonne River (south‐west France). Periodical sampling provided a biomass data set to compare with simulations from the model of Uehlinger, Bürher and Reichert (1996: Freshwater Biology, 36 , 249–263.), in order to evaluate the impact of hydraulic disturbance. 2. Despite differences in application conditions (e.g. river size, discharge, frequency of disturbance), the base equation satisfactorily predicted biomass between low and high water periods of the year, suggesting that the flood disturbance regime may be considered a universal mechanism controlling periphyton biomass. 3. However modelling gave no agreement with biomass dynamics during the 7‐month long low water period that the river experienced. The influence of other biomass‐regulating factors (temperature, light and soluble reactive phosphorus) on temporal biomass dynamics was weak. 4. Implementing a supplementary mechanism corresponding to a temperature‐dependent self‐generated loss because of heterotrophic processes allowed us to accurately reproduce the observed pattern: a succession of two peaks. This case study suggests that during typical summer low water periods (flow stability and favourable temperature) river biofilm modelling requires self‐generated detachment to be considered.     

血革螨科二新种（蜱螨亚纲）

本文记述了血革螨科两新种:大理血革螨Haemogamasus daliensis sp.nov.和中华真厉螨Eulaelaps sinensis sp.nov.。该文对新种的形态特征作了描述,并与近似种进行了比较。     

中国的角石蛾属昆虫(毛翅目:角石蛾科)

McLachlan(1866)根据采自印度北部阿萨姆Assam的一只雄虫,描述新种灰翅角石蛾Stcnopsyche griseipennis McLachlan并做为模式种,而建立角石蛾属StenopsycheMcLachlan,置于纹石蛾科Hydropsychidae.Ulmer(1907)将前人称之的纹石蛾科分为纹石蛾科(狭义),多距石蛾科Polycentropidae等翅石峨科Philopotomidae和管石蛾科Psychomyiidae。他根据角石蛾属有3个单眼和前足胫节有3个距而置于等翅石蛾科中;但角石蛾属在翅形、脉相、体躯大小和外生殖器等方面与等翅石蛾科的差别极为明显。Banks(1913)认为Ulmer所述的4科,仅能被认为是纹石蛾科中的4个亚科,他将角石     

Molecular characterization of β-thalassemia in Czechoslovakia

Summary We have identified different -thalassemia mutations in 93 members of 34 families of Czech or Slovakian descent using gene amplification, hybridization with specific ³²P-labeled oligonucleotide probes, sequencing of amplified DNA, and gene mapping. The GA mutation at IVS-I-1 was found in 18 families; other Mediterranean mutations were IVS-II-1 (GA), IVS-II-745 (CG), IVS-I-110 (GA), and codon 39 (CT); these were present in 9 additional families. The GT mutation at codon 121, known to cause Heinzbody -thalassemia, was present in 3 families, and the frameshift at codons 82/83 (-G), first described in the Azerbaijanian population, in 2 families. A newly discovered allele was a frameshift at codons 38/39 (-C). One -thalassemia allele was incompletely characterized. We observed in 2 families a TC mutation at position +96 UTR (untranslated region) relative to the termination codon; this mutation likely is a rare polymorphism, -Thalassemia was rare; only one person carried the -^3.7 heterozygosity, and one other had a yet to be identified -thalassemia-1, while seven had the ^{anti 3.7} triplication.     

休眠与萌发过程中苹果种子的呼吸代谢

“秦冠”苹果种子的总呼吸强度和EMP途径的呼吸强度在2℃条件下层积之后逐渐增加,解除休眠临界期大体在层积后第30天发生,此后增长速度较快。HMP途径和TCAC在临界期之前变化极慢,而后急剧增加。种子萌发后子叶和胚轴的总呼吸强度、EMP和TCAC初期呈急剧上升趋势,大约当胚轴长度达2cm时迅速下降,HMP在萌发过程中始终呈上升趋势。细胞透性层积之后逐渐降低,解除休眠至萌发阶段呈上升趋势。用不同浓度呼吸抑制剂处理解除休眠种子的试验结果表明,除1mM碘乙酸能明显刺激萌发和生长外,NaCN、SHAM和丙酮酸都表现为抑制作用。     

小量个体人血清中补体成分C_4的纯化

 <正> 补体成分的多态现象,特别是对人C4多态现象的研究,是近年来补体研究进展的一个重要方面。1969年Roseufeld等报告了人补体C4的多态现象以后,Teisberg等(1976)率先应用免疫固定电泳研究C4多态现象。这是当前研究补体多态现象的通用方法。1978年O’Neill等报告人的C4F和C4S分别由C4A和C4B两个基因座位控制,并分别与Rodgers和Chido血型抗原相应。现已发现C4A共有13个别型,C4B共有22个别型。