Tissue specificity and the human protein interaction network

A protein interaction network describes a set of physical associations that can occur between proteins. However, within any particular cell or tissue only a subset of proteins is expressed and so only a subset of interactions can occur. Integrating interaction and expression data, we analyze here this interplay between protein expression and physical interactions in humans. Proteins only expressed in restricted cell types, like recently evolved proteins, make few physical interactions. Most tissue‐specific proteins do, however, bind to universally expressed proteins, and so can function by recruiting or modifying core cellular processes. Conversely, most ‘housekeeping’ proteins that are expressed in all cells also make highly tissue‐specific protein interactions. These results suggest a model for the evolution of tissue‐specific biology, and show that most, and possibly all, ‘housekeeping’ proteins actually have important tissue‐specific molecular interactions.     

The Serra da Mantiqueira, south-eastern Brazil, as a biogeographical barrier for fishes

Aim  To present a fish fauna survey from rivers draining the south-western region of the Serra da Mantiqueira, and to investigate the effectiveness of that mountain range as a biogeographical barrier isolating the fish faunas of the Paraíba do Sul basin and the upper Paraná river.
Location  Six drainages from the south-western portion of the Serra da Mantiqueira in the region of Campos do Jordão, Brazil, were studied. They included three drainages belonging to the Paraíba do Sul basin (Piracuama, Grande and Buenos), and three belonging to the Sapucaí basin, Rio Paraná system (Sapucaí-Mirim, upper Sapucaí and Santo Antônio).
Methods  The survey was conducted in two sampling trips supplemented by examination of specimens preserved in museum collections. Parsimony analysis of endemicity (PAE) was used to detect the hierarchy of relationships among the six drainages.
Results  A total of 47 species of fishes was recorded in the six drainages. The main watershed divide is an effective barrier between the two basins, with 28 species occurring exclusively in the Paraíba do Sul versant, and 15 occurring exclusively on the slope of the Sapucaí basin. The PAE of 18 species with cladistically informative distributions and unproblematic taxonomic diagnoses produced a single area cladogram, with complete congruence among 14 species.
Main conclusions  The main Mantiqueira watershed divide is an effective biogeographical barrier isolating the fish faunas of the Paraíba do Sul and the Sapucaí basin (upper Paraná system). Previous hypotheses of a past connection between the upper Paraná and the Paraíba do Sul are not supported by extant species distributions in the Serra da Mantiqueira region. Within-basin drainage differentiation, however, is relatively low.     

Ten microsatellite loci for evolutionary research on Nesospiza buntings

We tested 19 loci originally developed for Vidua and Geospiza, of which six Vidua loci were polymorphic and furthermore, developed four microsatellite loci for Nesospiza buntings. Allelic variation ranged from two to 13 alleles, with heterozygosity from 0 to 0.82. Ascertainment bias was evident as increased allelic diversity of loci developed for Nesospiza, versus those developed for Vidua. Two loci showed linkage, and several, deviation from Hardy–Weinberg equilibrium. We suggest such deviations are through introduction of new alleles by introgression, or of the Wahlund effect. These loci will contribute to the understanding of speciation in Nesospiza buntings of the Tristan da Cunha islands.     

Field observation of foraging behavior by a group of adult diving beetles Agabus (Gaurodytes) bipustulatus preying on an adult Lissotriton boscai

Adult dytiscids prey on a variety of items including other invertebrates but also larger prey such as frogs and fish. Observations of anuran larvae predation are common. However, there have been no reports concerning predation on caudata post‐metamorphosis by dytiscids. Here we describe a predation event by a group of adult diving beetles of the species Agabus (Gaurodytes) bipustulatus (Linnaeus, 1767) on an adult Lissotriton boscai (Lataste in Tourneville, 1879). This report represents the first observation of foraging behavior of adult diving beetles preying on and consuming a living post‐metamorphic newt.     

Transmission dynamics of Toxoplasma gondii along an urban-rural gradient

Recently, several authors have proposed that the availability of intermediate hosts (IHs) for definitive hosts (DHs) may contribute to determining the dynamics and evolutionary ecology of parasites with facultative complex life cycles. The protozoa Toxoplasma gondii may be transmitted to DHs either via predation of infected IHs through a complex life cycle (CLC) or directly from a contaminated environment through a simple life cycle (SLC). This parasite is also present in contrasting host density environments. We tested the hypothesis that the relative contributions of the CLC and SLC along an urban-rural gradient depend on the IH supply. We built and analysed a deterministic model of the T. gondii transmission cycle. The SLC relative contribution is important only in urban-type environments, i.e., with low predation rate on IHs. In contrast, the parasite is predominantly transmitted through a CLC in suburban and rural environments. The association of the two cycles enables the parasite to spread in situations of low IH availability and low DH population size for which each cycle alone is insufficient.     

塔克拉玛干沙漠腹地3种植物根系构型及其生境适应策略

 在塔克拉玛干沙漠腹地, 采用挖掘法挖取塔克拉玛干柽柳(Tamarix taklamakanensis)、塔克拉玛干沙拐枣(Calligonum roborovskii)和罗布麻(Apocynum venetum )根系, 对根系的拓扑结构特征进行了测定与分析。结果表明: 1) 3种植物根系均以水平分布占优势, 根系浅层化。2) 3种植物根系结构的适应性不同, 表现为两种不同的根系分支模式, 塔克拉玛干柽柳根系为叉状分支结构(q_a=0.15、q_b=0.09、TI=0.658), 罗布麻(q_a=0.43、q_b=0.35、TI=0. 83)和沙拐枣(q_a=0.52、q_b=0.38、TI=0.86)根系趋向于鱼尾形分支结构。3) 3种植物根系的连接长度都较大, 最小也达1.12 m, 说明在塔克拉玛干沙漠腹地, 3种植物通过增加连接长度来扩大根系在土层中的分布范围, 从而提高根系的有效营养空间, 增加根系连接长度是根系对沙漠腹地贫瘠土壤环境的一个良好适应。4)研究验证了Leonardo da Vinci法则, 即根系分支前的横截面积等于根系分支后的横截面积之和, 3种植物根系分支前后的横截面积符合Leonardo da Vinci法则。研究表明沙漠腹地3种植物根系构型特征既有相似性又有差异性, 在相似的沙漠环境中具有不同的根系适应策略。     

Direct electron transfer from graphite and functionalized gold electrodes to T1 and T2/T3 copper centers of bilirubin oxidase

Direct electron transfer (DET) from bare spectrographic graphite (SPGE) or 3-mercaptopropionic acid-modified gold (MPA-gold) electrodes to Trachyderma tsunodae bilirubin oxidase (BOD) was studied under anaerobic and aerobic conditions by cyclic voltammetry and chronoamperometry. On cyclic voltammograms nonturnover Faradaic signals with midpoint potentials of about 700 mV and 400 mV were clearly observed corresponding to redox transformations of the T1 site and the T2/T3 cluster of the enzyme, respectively. The immobilized BOD was differently oriented on the two electrodes and its catalysis of O₂-electroreduction was also massively different. On SPGE, where most of the enzyme was oriented with the T1 copper site proximal to the carbon with a quite slow ET process, well-pronounced DET-bioelectroreduction of O₂ was observed, starting already at > 700 mV vs. NHE. In contrast, on MPA-gold most of the enzyme was oriented with its T2/T3 copper cluster proximal to the metal. Indeed, there was little DET-based catalysis of O₂-electroreduction, even though the ET between the MPA-gold and the T2/T3 copper cluster of BOD was similar to that observed for the T1 site at SPGE. When BOD actively catalyzes the O₂-electroreduction, the redox potential of its T1 site is 690 mV vs. NHE and that of one of its T2/T3 copper centers is 390 mV vs. NHE. The redox potential of the T2/T3 copper cluster of a resting form of BOD is suggested to be about 360 mV vs. NHE. These values, combined with the observed biocatalytic behavior, strongly suggest an uphill intra-molecular electron transfer from the T1 site to the T2/T3 cluster during the catalytic turnover of the enzyme.     

Difficoltà negli studi aerobiologici ed allergologici sui miceti

Riassunto In allergologia clinica la sensibilizzazione da miceti ha un ruolo di importanza secondaria rispetto a quella da pollini, ma le nostre conoscenze sul ruolo allergenico delle spore e di altre emanazioni atmosferiche dei miceti sono però stato largemente insoddisfacenti. Contrariamente a quanto avviene per i granuli pollinici, la cui sede di origine, la pianta che li produce, è ben visibile nell'ambiente, per le spore dei miceti è frequentemente impossibile evidenziare la sorgente fungina di appartenenza. Maggiore importanza assumono quindi l'identificazione e la misura della loro concentrazione nell'atmosfera. Il campionamento aerosporologico può essere effettuato con apparecchi volumetrici tipo Hirst che permettono però il solo riconoscimento di alcune spore e non di altre, come quelle di Aspergilli e Penicilli. Per quest'ultime appare più utile la captazione mediante capsule di Petri esposte isolatamente o in un apparecchio campionatore a multistadi del tipo dell'Andersen. Per quanto riguarda i riflessi in allergologia clinica la scarsa frequenza di sensibilizzazione da miceti è verosimilmente da collegare alla carente purificazione e standardizzazione degli estratti allegenici utilizzati. Non esiste infatti un'uniformità nei metodi di estrazione delle componenti allergeniche e quindi c'è molta variabilità nel contenuto antigenico ed allergenico degli estratti di ditte diverse o della stessa ditta in tempi diversi. C'è inoltre da considerare che, contrariamente a quanto avviene per i pollini, non esiste per i miceti una ben definita stagione di presenza ambientale di spore fungine sì da consentire una correlazione con la sintomatologia clinica. La stagione fungina dell'atmosfera libera è infatti frequentemente integrata dalla presenza delle stesse spore all'interno delle abitazioni e/o degli ambienti di lavoro per cui l'esposizione diventa di tipo perenne.      

Natural regeneration in the context of large‐scale forest and landscape restoration in the tropics

Large‐scale and long‐term restoration efforts are urgently needed to reverse historical global trends of deforestation and forest degradation in the tropics. Restoration of forests within landscapes offers multiple social, economic, and environmental benefits that enhance lives of local people, mitigate effects of climate change, increase food security, and safeguard soil and water resources. Despite rapidly growing knowledge regarding the extent and feasibility of natural regeneration and the environmental and economic benefits of naturally regenerating forests in the tropics, tree planting remains the major focus of restoration programs. Natural regeneration is often ignored as a viable land‐use option. Here, we assemble a set of 16 original papers that provide an overview of the ecological, economic, and social dimensions of forest and landscape restoration (FLR), a relatively new approach to forest restoration that aims to regain ecological integrity and enhance human well‐being in deforested or degraded forest landscapes. The papers describe how spontaneous (passive) and assisted natural regeneration can contribute to achieving multiple social and ecological benefits. Forest and landscape restoration is centered on the people who live and work in the landscape and whose livelihoods will benefit and diversify through restoration activities inside and outside of farms. Given the scale of degraded forestland and the need to mitigate climate change and meet human development needs in the tropics, harnessing the potential of natural regeneration will play an essential role in achieving the ambitious goals that motivate global restoration initiatives.