CCDC61/VFL3 Is a Paralog of SAS6 and Promotes Ciliary Functions

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Genetic variation for foot-rot and Fusarium head-blight resistances among full-sib families of a self-incompatible winter rye (Secale cereale L.) population

The amount of genetic variation for resistance to foot rot caused by Pseudocercosporella herpotrichoides, Fusarium spp., and Microdochium nivale and for resistance to head blight caused by Fusarium culmorum are important parameters when estimating selection gain from recurrent selection in winter rye. One-hundred and eighty-six full-sib families of the selfincompatible population variety Halo, representing the Petkus gene pool, were tested for foot-rot resistance at five German location-year combinations (environments) and for head-blight resistance in three environments with artificial inoculation in all but one environment. Foot-rot rating was based on 25 stems per plot scored individually on a 1–9 scale. Head-blight resistance was plotwise scored on a 1–9 scale and, additionally, grain-weight per spike was measured relative to the non-inoculated control plots. Significant estimates of genotypic variance and medium-sized heritabilities (h ²=0.51–0.69) were observed in the combined analyses for all resistance traits. In four out of five environments, the amount of genetic variance was substantially smaller for foot-rot than for head-blight rating. Considerable environmental effects and significant genotype-environment interactions were found for both foot-rot and head-blight resistance. Coefficients of error-corrected correlation among environments were considerably closer than phenotypic correlations. No significant association was found between the resistances to both diseases (r=-0.20 to 0.17). In conclusion, intra-population improvement by recurrent selection should lead to substantial higher foot-rot and head-blight resistances due to significant quantitative genetic variation within Halo. Selection should be carried out in several environments. Lack of correlation between foot-rot and head-blight resistance requires separate infection tests for improving both resistances.     

From the Schnauzenorgan to the back: Morphological comparison of mormyromast electroreceptor organs at different skin regions of Gnathonemus petersii

The nocturnally active weakly electric fish Gnathonemus petersii is known to employ active electrolocation for the detection of objects and for orientation in its environment. The fish emits pulse‐type electric signals with an electric organ and perceives these signals with more than 3,000 epidermal electroreceptor organs, the mormyromasts, which are distributed over the animal's skin surface. In this study, we measured the metric dimensions of the mormyromasts from different body regions to find structural and functional specialization of the various body parts. We focused on the two foveal regions of G. petersii, which are located at the elongated and movable chin (the Schnauzenorgan; SO) and at the nasal region (NR), the skin region between the mouth and the nares. These two foveal regions were compared to the dorsal part (back) of the fish, which contains typical nonfoveal mormyromasts. While the gross anatomy of the mormyromasts from all skin regions is similar, the metric dimensions of the main substructures differed. The mormyromasts at the SO are the smallest and contain the smallest receptor cells. In addition, the number of receptor cells per organ is lowest at the SO. In contrast, at the back the biggest receptor organs with the highest amount of receptor cells per organ occur. The mormyromasts at the NR are in several respects intermediate between those from the back and the SO. However, mormyromasts at the NR are longer than those at all other skin regions, the canal leading from the receptor pore to the inner chambers were the longest and the overlaying epidermal layers are the thickest. These results show that mormyromasts and the epidermis they are embedded in at both foveal regions differ specifically from those found on the rest of the body. The morphological specializations lead to functional specialization of the two foveae. J. Morphol., 2012. © 2012 Wiley Periodicals, Inc.     

Field Hypothesis on the Self-regulation of Gene Expression

The mechanism of the self-regulation of gene expression in living cells is generally explained by considering complicated networks of key-lock relationships, and in fact there is a large body of evidence on a hugenumber of key-lock relationships. However, in the present article we stress that with the network hypothesis alone it is impossible to fully explain the mechanism of self-regulation in life. Recently, it has been established that individual giant DNA molecules, larger than several tens of kilo base pairs, undergo a large discrete transition in their higher-order structure. It has become clear that nonspecific weak interactions with various chemicals, suchas polyamines, small salts, ATP and RNA, cause on/off switching in the higher-order structure of DNA. Thus, the field parameters of the cellular environment should play important roles in the mechanism of self-regulation, in addition to networks of key and locks. This conformational transition induced by field parameters may be related to rigid on/off regulation, whereas key-lock relationships may be involved in a more flexible control of gene expression.     

A型激酶锚定蛋白及其复合物结构与功能

A型激酶锚定蛋白(A-kinase anchoring proteins，AKAPs)是一类结构不同而功能相关的蛋白家族，其主要功能是将cAMP依赖性蛋白激酶A（PKA）锚定于特定的亚细胞结构.PKA是第二信使cAMP的主要效应器，而AKAPs在靶向定位和调节PKA介导的磷酸化事件方面扮演重要角色. AKAPs更为重要的功能是与多种信号分子形成信号复合物，从时间和空间上整合cAMP-PKA和其他信号途径.本文将对AKAPs及其信号复合物的结构特点和参与细胞信号转导的功能机制及其研究现状进行概述.     

CLUE-S模型在南京市土地利用变化研究中的应用

土地利用/覆盖变化模型是研究区域景观动态并解释其驱动机制的重要技术手段.应用CLUE-S模型,在Landsat TM影像等相关数据支持下,对南京地区1998-2006年土地利用的时空动态变化进行了研究.结果表明:各土地利用类型变化受地形因素影响最大,人均GDP与城镇用地和农业用地的分布呈显著相关,城乡主干道对土地利用变化的贡献显著大于省级及以上道路;海拔较高区域林地的发生比率较高,而地形低平区域农田、城建用地的发生比率较高.经检验,在300 m空间分辨率水平,对南京地区2003年、2006年土地利用状况模拟的精度分别达到了85.7%和84.1%;而通过将研究区分成若干子区,分别修正模型参数并重新模拟,准确率提高到89.7%和88.3%,分区赋值法有效地提高了模拟精度.研究表明,CLUE-S模型对城市发展的空间结构也有较强的预测能力,对指导城市规划、分析景观动态的驱动机制有重要参考价值.     

An enhanced topologically significant directed random walk in cancer classification using gene expression datasets

Microarray technology has become one of the elementary tools for researchers to study the genome of organisms. As the complexity and heterogeneity of cancer is being increasingly appreciated through genomic analysis, cancerous classification is an emerging important trend. Significant directed random walk is proposed as one of the cancerous classification approach which have higher sensitivity of risk gene prediction and higher accuracy of cancer classification. In this paper, the methodology and material used for the experiment are presented. Tuning parameter selection method and weight as parameter are applied in proposed approach. Gene expression dataset is used as the input datasets while pathway dataset is used to build a directed graph, as reference datasets, to complete the bias process in random walk approach. In addition, we demonstrate that our approach can improve sensitive predictions with higher accuracy and biological meaningful classification result. Comparison result takes place between significant directed random walk and directed random walk to show the improvement in term of sensitivity of prediction and accuracy of cancer classification.     

Alpha/beta‐hydrolases: A unique structural motif coordinates catalytic acid residue in 40 protein fold families

The alpha/beta‐hydrolases are a family of acid‐base‐nucleophile catalytic triad enzymes with a common fold, but using a wide variety of substrates, having different pH optima, catalyzing unique catalytic reactions and often showing improved chemical and thermo stability. The ABH enzymes are prime targets for protein engineering. Here, we have classified active sites from 51 representative members of 40 structural ABH fold families into eight distinct conserved geometries. We demonstrate the occurrence of a common structural motif, the catalytic acid zone, at the catalytic triad acid turn. We show that binding of an external ligand does not change the structure of the catalytic acid zone and both the ligand‐free and ligand‐bound forms of the protein belong to the same catalytic acid zone subgroup. We also show that the catalytic acid zone coordinates the position of the catalytic histidine loop directly above its plane, and consequently, fixes the catalytic histidine in a proper position near the catalytic acid. Finally, we demonstrate that the catalytic acid zone plays a key role in multi‐subunit complex formation in ABH enzymes, and is involved in interactions with other proteins. As a result, we speculate that each of the catalytic triad residues has its own supporting structural scaffold, similar to the catalytic acid zone, described above, which together form the extended catalytic triad motif. Each scaffold coordinates the function of its respective catalytic residue, and can even compensate for the loss of protein function, if the catalytic amino acid is mutated.     

Species‐dependent microarchitectural traits of iridescent scales in the triad taxa of Ornithoptera birdwing butterflies

Ornithoptera birdwing butterflies have blue, green, or orange iridescent scales in different species or subspecies. To understand the species‐ or subspecies‐dependent scale color differences, we performed comparative morphometric analyses of iridescent scales from three closely related taxa: O. priamus priamus (green), O. priamus urvillianus (blue), and O. croesus (orange). The three types of Ornithoptera wings exhibited reversible color changes to longer wavelengths with different kinetics upon immersion in methanol, suggesting that their color differences are at least partly based on differences in the size of air cavities made by nanostructures. Cover scales of all three color types were visually semi‐transparent glass scales that exhibited color when placed on a dark background. The dorsoventral differences in coloration were observed in single scales, suggesting the optical importance of scale surfaces. Scanning electron microscopy of cover scales in cross section revealed that all color types exhibited finely sculpted tapered ridges and thick, irregular basal multilayers containing tandemly clustered granular objects and air cavities. Scale thickness, ridge height, and multilayer thickness were significantly different among the three color types, and granular object size was significantly different between orange scales and blue and green scales. We conclude that each of the three taxa of Ornithoptera butterflies possesses unique quantitative size values on tapered ridges and irregular multilayers with granular objects and air cavities to express unique structural color. These species‐ or subspecies‐dependent structural colors might have evolved via quantitative shifts in these microarchitectural traits rather than via changes in the basic developmental or architectural plan for color expression.