Biological implications of genetic variations in autism spectrum disorders from genomics studies

Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental condition characterized by atypical social interaction and communication together with repetitive behaviors and restricted interests. The prevalence of ASD has been increased these years. Compelling evidence has shown that genetic factors contribute largely to the development of ASD. However, knowledge about its genetic etiology and pathogenesis is limited. Broad applications of genomics studies have revealed the importance of gene mutations at protein-coding regions as well as the interrupted non-coding regions in the development of ASD. In this review, we summarize the current evidence for the known molecular genetic basis and possible pathological mechanisms as well as the risk genes and loci of ASD. Functional studies for the underlying mechanisms are also implicated. The understanding of the genetics and genomics of ASD is important for the genetic diagnosis and intervention for this condition.     

Using a dry electrode EEG device during balance tasks in healthy young-adult males: Test–retest reliability analysis

Abstract

Background: The analysis of brain activity during balance is an important topic in different fields of science. Given that all measurements involve an error that is caused by different agents, like the instrument, the researcher, or the natural human variability, a test–retest reliability evaluation of the electroencephalographic assessment is a needed starting point. However, there is a lack of information about the reliability of electroencephalographic measurements, especially in a new wireless device with dry electrodes.

Objective: The current study aims to analyze the reliability of electroencephalographic measurements from a wireless device using dry electrodes during two different balance tests.

Method: Seventeen healthy male volunteers performed two different static balance tasks on a Biodex Balance Platform: (a) with two feet on the platform and (b) with one foot on the platform. Electroencephalographic data was recorded using Enobio (Neuroelectrics). The mean power spectrum of the alpha band of the central and frontal channels was calculated. Relative and absolute indices of reliability were also calculated.

Results: In general terms, the intraclass correlation coefficient (ICC) values of all the assessed channels can be classified as excellent (>0.90). The percentage standard error of measurement oscillated from 0.54% to 1.02% and the percentage smallest real difference ranged from 1.50% to 2.82%.

Conclusion: Electroencephalographic assessment through an Enobio device during balance tasks has an excellent reliability. However, its utility was not demonstrated because responsiveness was not assessed.     

Crystal structure of R22L trichosanthin

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Resveratrol prevents alcohol-induced cognitive deficits and brain damage by blocking inflammatory signaling and cell death cascade in neonatal rat brain

Human prenatal ethanol exposure that occurs during a period of increased synaptogenesis known as the 'brain growth spurt' has been associated with significant impairments in attention, learning and memory. Recent studies have shown that administration of ethanol to infant rats during the synaptogenesis period (first 2 weeks after birth) triggers extensive apoptotic neurodegeneration throughout many regions of the developing brain and results in cognitive dysfunctions as the animal matures. The present study was designed with an aim to investigate the effect of resveratrol, a polyphenolic phytoalexin (trans-3,5,4-trihydroxy stilbene) present in red wine on alcohol-induced cognitive deficits and neuronal apoptosis in rat pups postnatally exposed to ethanol. Pups were administered ethanol (5 g/kg, 12% v/v) by intragastric intubation on postnatal days 7, 8, and 9. Ethanol-exposed pups showed impaired memory performance in both Morris water maze elevated plus maze task recorded by using computer tracking with EthoVision software. Behavioral deficit in ethanol-exposed pups was associated with enhanced acetylcholinesterase activity, increased oxidative-nitrosative stress, cytokine (TNF-α, IL-1β and TGF-β), nuclear factor kappa beta and caspase 3 levels in both cerebral cortex and hippocampus. Chronic treatment with resveratrol (10 and 20 mg/kg) significantly attenuated all the behavioral, biochemical and molecular changes in different brain regions of ethanol administered pups. The major finding of the study is that resveratrol blocks activation of nuclear factor kappa beta pathway and apoptotic signaling and prevents cognitive deficits in rats postnatally exposed to ethanol.     

Acute metal stress in Populus tremula×P. alba (717‐1B4 genotype): Leaf and cambial proteome changes induced by cadmium2+

The comprehension of metal homeostasis in plants requires the identification of molecular markers linked to stress tolerance. Proteomic changes in leaves and cambial zone of Populus tremula×P. alba (717‐1B4 genotype) were analyzed after 61 days of exposure to cadmium (Cd) 360 mg/kg soil dry weight in pot‐soil cultures. The treatment led to an acute Cd stress with a reduction of growth and photosynthesis. Cd stress induced changes in the display of 120 spots for leaf tissue and 153 spots for the cambial zone. It involved a reduced photosynthesis, resulting in a profound reorganisation of carbon and carbohydrate metabolisms in both tissues. Cambial cells underwent stress from the Cd actually present inside the tissue but also a deprivation of photosynthates caused by leaf stress. An important tissue specificity of the response was observed, according to the differences in cell structures and functions.     

Taylor's law and body size in exploited marine ecosystems

Taylor's law (TL), which states that variance in population density is related to mean density via a power law, and density‐mass allometry, which states that mean density is related to body mass via a power law, are two of the most widely observed patterns in ecology. Combining these two laws predicts that the variance in density is related to body mass via a power law (variance‐mass allometry). Marine size spectra are known to exhibit density‐mass allometry, but variance‐mass allometry has not been investigated. We show that variance and body mass in unexploited size spectrum models are related by a power law, and that this leads to TL with an exponent slightly <2. These simulated relationships are disrupted less by balanced harvesting, in which fishing effort is spread across a wide range of body sizes, than by size‐at‐entry fishing, in which only fish above a certain size may legally be caught.     

Divalent metal ion complexes of S100B in the absence and presence of pentamidine

As part of an effort to inhibit S100B, structures of pentamidine (Pnt) bound to Ca²⁺-loaded and Zn²⁺,Ca²⁺-loaded S100B were determined by X-ray crystallography at 2.15 Å (R_free = 0.266) and 1.85 Å (R_free = 0.243) resolution, respectively. These data were compared to X-ray structures solved in the absence of Pnt, including Ca²⁺-loaded S100B and Zn²⁺,Ca²⁺-loaded S100B determined here (1.88 Å; R_free = 0.267). In the presence and absence of Zn²⁺, electron density corresponding to two Pnt molecules per S100B subunit was mapped for both drug-bound structures. One Pnt binding site (site 1) was adjacent to a p53 peptide binding site on S100B (± Zn²⁺), and the second Pnt molecule was mapped to the dimer interface (site 2; ± Zn²⁺) and in a pocket near residues that define the Zn²⁺ binding site on S100B. In addition, a conformational change in S100B was observed upon the addition of Zn²⁺ to Ca²⁺-S100B, which changed the conformation and orientation of Pnt bound to sites 1 and 2 of Pnt-Zn²⁺,Ca²⁺-S100B when compared to Pnt-Ca²⁺-S100B. That Pnt can adapt to this Zn²⁺-dependent conformational change was unexpected and provides a new mode for S100B inhibition by this drug. These data will be useful for developing novel inhibitors of both Ca²⁺- and Ca²⁺,Zn²⁺-bound S100B.     

Trade‐off relationship between productivity and thallus toughness in Laminariales (Phaeophyceae)

Trade‐off relationships are considered key to understanding the mechanisms supporting the coexistence of multiple species within kelp beds. Thus, information on trade‐offs is expected to contribute to conservation of kelp bed diversity. To test the existence of a trade‐off between productivity and thallus toughness, thallus traits and relationships between the traits were examined for seven species of Laminariales including 24 populations. For each population, photosynthetic capacity per unit biomass (as A _mass) and nitrogen (i.e., photosynthetic nitrogen‐use efficiency, PNUE), nitrogen content (as N _mass), thallus mass per unit thallus area (as TMA) and force required to penetrate the thallus (as F _p, a common index of leaf toughness in land plants by punch test) were determined. A _mass increased with increasing N _mass. Blades with high N _mass showed high A _mass. These blades may invest a large proportion of nitrogen to the photosynthetic parts, and consequently exhibit high metabolic rates. Moreover, blades with high N _mass tended to be associated with low TMA, and N _mass decreased with increasing TMA. A significant negative correlation was observed between TMA and A _mass because of the linkage of high A _mass with high N _mass and high N _mass associated with low TMA, while a significant positive correlation was observed between TMA and F _p. The two correlations indicate the existence of a trade‐off between productivity and thallus toughness in Laminariales. PNUE showed a significant negative correlation with TMA, which also showed a significant positive correlation with F _p as the index of thallus toughness, and therefore a trade‐off relationship between productivity and thallus toughness.     

鸡基因组差异表达基因翻译起始密码子上下游序列的比较研究

翻译起始调控是基因表达调控的一个关键步骤之一。本文以鸡为研究材料,比较研究了鸡基因组高表达基因和低表达基因翻译起始密码子上下游的碱基序列差异,旨在寻找影响鸡基因表达水平的特异性调控位点。全部3 020个单剪接基因完整的mRNA序列及有详细注释的5＇UTRs序列从Ensembl下载。编写计算机程序,读取每个基因mRNA起始密码子上下游各位点的碱基。研究发现,起始密码子上游-3、-2位点可能是鸡基因组基因表达起始密码子正确识别的关键位点。起始密码子上下游的碱基组成分析发现,高表达基因和低表达基因起始密码子的上游均倾向使用（G＋C）,高表达基因的使用偏倚尤为强烈。序列差异比较发现,高表达基因在-9、-6、-3、＋4位点显著偏向G,在-1、-2、-4、-5位点显著偏向C。低表达基因起始密码子上游使用A、U的频率显著高于低表达基因。在-19位点强烈偏向A,在＋1、＋11、＋14位点强烈偏向U。     

紫球藻藻红蛋白的分离纯化及光谱学特性

采用4℃反复浸提、离心、硫酸铵沉淀、DEAE—Sepharose Fast Flow离子交换柱层析,从紫球藻（Porphyridium cruentum Naegeli）冻干粉中分离纯化藻红蛋白,分离纯度达到4．85,总收率51．9％;经羟基磷灰石柱层析纯化,藻红蛋白纯度达到5．10,总收率34．0％,聚丙烯酰胺凝胶电泳显示1条带。所分离纯化的藻红蛋白含有3个亚基（α、β、γ）,在可见光区545nm和560nm处有2个吸收峰,在498nm处有1个吸收肩峰。实验结果说明所分离纯化的藻红蛋白纯度符合要求。