Bacterial and fungal communities associated with Tuber magnatum‐productive niches

Abstract

Truffles are hypogeous ectomycorrhizal fungi of ecological interest for forestry in soils of the northern hemisphere, and of economical relevance for food markets worldwide. The molecular mechanisms that control truffle body formation are largely unknown, as well as the environmental factors that are likely involved. Among the latter, it has been hypothesized that soil‐borne communities may have an impact on truffle production. To address this question, we investigated bacterial and fungal communities resident in productive versus adjacent non‐productive grounds of the white truffle Tuber magnatum by using PCR‐DGGE. Although bacterial communities were generally highly similar across all samples within the grounds, profiles did cluster according to the productivity of circumscribed niches, and a Moraxella osloensis population appeared to be associated with productive sites. Fungal communities revealed several populations, yet showed no obvious patterns in relation to productivity, although Mortierella and Fusarium oxysporum appeared to be more abundant in the productive area. Our results offer a first glimpse into microbial communities thriving in truffle productive niches, and open the question as to whether microbe‐mediated mechanisms may facilitate/inhibit truffle fruiting‐body production or, vice versa, i.e. whether truffle sporocarps have an impact on the microbes living in the rhizosphere.     

Bone morphogenic proteins signaling in adipogenesis and energy homeostasis

A great deal is known about the molecular mechanisms regulating terminal differentiation of pre-adipocytes into mature adipocytes. In contrast, the knowledge about pathways that trigger commitment of mesenchymal stem cells into the adipocyte lineage is fragmented. In recent years, the role of members of the bone morphogenic protein family in regulating the early steps of adipogenesis has been the focus of research. Findings based on these studies have also highlighted an unexpected role for some bone morphogenic protein in energy homeostasis via regulation of adipocyte development and function. This review summarizes the knowledge about bone morphogenic proteins and their role in adipocyte commitment and regulation of whole body energy homeostasis. This article is part of a Special Issue entitled Brown and White Fat: From Signaling to Disease.     

Why fluorescent probes for endoplasmic reticulum are selective: an experimental and QSAR-modelling study

The basis of the selectivity of fluorochromes routinely used to visualize the endoplasmic reticulum (ER) in live cells remains obscure. To clarify this, interactions of living cells with fluorochromes of varied physicochemical properties were analyzed experimentally and numerically using a quantitative structure activity relationship analysis (QSAR). Routine selective ER probes were found to be amphipathic, lipophilic cations with moderate-sized conjugated systems. The moderately lipophilic character permits probe uptake by passive diffusion without nonspecific accumulation in biomembranes. The moderately amphipathic character favors uptake into the ER, perhaps owing to its high concentration of zwitterionic lipid head-groups. The QSAR model rationalizes the impractical character of some ER probes mentioned in the literature, and could permit design of novel ER probes with different emission colors. The possibility of using the QSAR model as a tool to predict the accumulation of xenobiotics in the ER of living cells is illustrated by the localization of certain antipsychotic drugs in cultured cells.     

复合载体固定亚硝酸盐氧化菌处理养殖废水

利用新型复合载体固定亚硝酸盐氧化菌,确定了挂膜条件,考察了水力停留时间对NO2--N去除率的影响,并进行对虾养殖水处理.结果表明,新型载体可以较好地固定亚硝酸盐氧化菌,在水力停留时间为12 h、6 h、3 h、1 h的条件下,NO2--N的最大去除率分别为100%、98.77%、90.59%、59.02%.在HRT为1 h时,固定化的亚硝酸盐氧化菌可以高效去除养殖水体中的NO2--N,去除率达76.94%.     

Study of Hepatocytes Polyploidization Peculiarities in Cholestatic Liver of Adult Rats

According to the literature, different mechanisms and kinetics proceeding of regenerative growth has been established using the basic models of liver regeneration (after resection or chemically induced). Hence, in order to determine general regularities of the adaptive-compensatory processes in various pathological conditions, the processes taking place in the cholestatic liver of adult white rats during the first four days after common bile duct ligation have been studied. It has been shown that in cholestatic liver, compensatory-adaptive processes take place with different kinetics compared to those after resection. In particular, in response to the increased functional load caused by destructive processes during cholestasis, the liver, at an early stage, responds by simple division of high ploidy (binuclear tetraploid) cells and further provides their quantitative increase. The difference between the processes taking place in cholestatic and resected liver is more expressed on the third and fourth day after common bile duct ligation. In particular, 4c cells are still highest in cholestatic liver, while all ploidy cells are present in equal numbers in the regenerated liver after resection. This fact of compensatory growth characteristic for reparative regeneration was not detected in cholestatic liver at the mentioned date.     

Body mass and hibernation microclimate may predict bat susceptibility to white‐nose syndrome

In multihost disease systems, differences in mortality between species may reflect variation in host physiology, morphology, and behavior. In systems where the pathogen can persist in the environment, microclimate conditions, and the adaptation of the host to these conditions, may also impact mortality. White‐nose syndrome (WNS) is an emerging disease of hibernating bats caused by an environmentally persistent fungus, Pseudogymnoascus destructans. We assessed the effects of body mass, torpid metabolic rate, evaporative water loss, and hibernaculum temperature and water vapor deficit on predicted overwinter survival of bats infected by P. destructans. We used a hibernation energetics model in an individual‐based model framework to predict the probability of survival of nine bat species at eight sampling sites across North America. The model predicts time until fat exhaustion as a function of species‐specific host characteristics, hibernaculum microclimate, and fungal growth. We fit a linear model to determine relationships with each variable and predicted survival and semipartial correlation coefficients to determine the major drivers in variation in bat survival. We found host body mass and hibernaculum water vapor deficit explained over half of the variation in survival with WNS across species. As previous work on the interplay between host and pathogen physiology and the environment has focused on species with narrow microclimate preferences, our view on this relationship is limited. Our results highlight some key predictors of interspecific survival among western bat species and provide a framework to assess impacts of WNS as the fungus continues to spread into western North America.     

城口产“平术”的品种鉴别

目的:城口产"平术"具有悠久的历史,一直以来作为白术的一个品种在当地收购流通使用,但从其植物形态和长期临床应用发现其更接近苍术,故对其品种进行鉴别,以便更加合理指导用药。方法:通过产地追踪调查、标本对照、显微观察、薄层色谱等方法对其品种进行鉴别。结果:平术在原植物植物形态和显微特征与白术差异较大,且与苍术接近,同时含苍术素。结论:城口产"平术"为苍术Atractylodes lancea(Thunb.)DC.     

Density of Ixodes scapularis ticks on Monhegan Island after complete deer removal: A question of avian importation?

Questing adult blacklegged tick (Ixodes scapularis Say) abundance declined markedly three years after the 1999 removal of white‐tailed deer (Odocoileus virginianus Zimmermann) from Monhegan Island, ME. Since 2000, subadult ticks have not been found on Norway rats (Rattus norvegicus Berkenhout); questing nymphs have not been found since 2002. This suggested I. scapularis was reintroduced annually via bird importation of subadult ticks, but unable to complete its two‐year life cycle on the island due to lack of deer. To investigate this, we used uncertainty analysis to estimate 1) questing adult ticks/ha that would result from avian importation of nymphs, and 2) questing adult ticks/ha on Monhegan Island, using bird capture and tick burden data from Appledore Island, ME, flagged tick data from Monhegan Island, and ten uncertain parameters. During the deer‐fed period (1990–2001), estimated tick density on Monhegan Island was 18 times greater than that of imported ticks. During the post‐deer‐fed period (2002–2008), Monhegan Island tick density was equivalent to imported tick density. This supported the premise that all I. scapularis ticks on Monhegan Island have been bird‐derived since 2002.