Mapping <Emphasis Type="Italic">O</Emphasis>-GlcNAc modification sites on tau and generation of a site-specific <Emphasis Type="Italic">O</Emphasis>-GlcNAc tau antibody

The microtubule-associated protein tau is known to be post-translationally modified by the addition of N-acetyl-d-glucosamine monosaccharides to certain serine and threonine residues. These O-GlcNAc modification sites on tau have been challenging to identify due to the inherent complexity of tau from mammalian brains and the fact that the O-GlcNAc modification typically has substoichiometric occupancy. Here, we describe a method for the production of recombinant O-GlcNAc modified tau and, using this tau, we have mapped sites of O-GlcNAc on tau at Thr-123 and Ser-400 using mass spectrometry. We have also detected the presence of a third O-GlcNAc site on either Ser-409, Ser-412, or Ser-413. Using this information we have raised a rabbit polyclonal IgG antibody (3925) that detects tau O-GlcNAc modified at Ser-400. Further, using this antibody we have detected the Ser-400 tau O-GlcNAc modification in rat brain, which confirms the validity of this in vitro mapping approach. The identification of these O-GlcNAc sites on tau and this antibody will enable both in vivo and in vitro experiments designed to understand the possible functional roles of O-GlcNAc on tau.     

Seven loci on human Chromosome 4 map onto sheep Chromosome 6: a proposal to restore the original nomenclature of this sheep chromosome

Seven new loci, casein alpha-S1 (CSN1S1), casein alpha-S2 (CSN1S2), casein beta (CSN2), the Hardy-Zuckerman 4 feline sarcoma viral (v-kit) oncogene homolog (KIT), albumin (ALB), phosphodiesterase cyclic GMP (rod receptor) beta polypeptide (PDEB), and complement component 1 (IF), were assigned to sheep Chromosome (Chr) 6 by Southern hybridization to a panel of chromosomally characterized sheep x hamster cell hybrids. By isotopic in situ hybridization, CSN2 was regionally localized to sheep Chr (OOV) 6q22–q31, anchoring this syntenic group of markers on to OOV6 and confirming its homology at a molecular and cytological level with cattle Chr 6. The assignment of these loci, from PDEB (located on human Chr 4p16.3) to IF (on HSA4q24–q25), and the observation that interleukin 2 (IL2, on HSA 4q26–q27) and tryptophan 2,3-dioxygenase (TDO2, on HSA4q31) are not located on OOV6, is further evidence of the close evolutionary relationship of sheep and cattle and the conserved synteny in these species of this extensive region of human Chr 4. On the basis of this conserved synteny, and the similar G- and Q-banding patterns of this chromosome in cattle and sheep, we propose that this sheep chromosome be numbered as 6, not 4 as recommended by ISCNDA (1990).     

Effect of a native tree on seedling establishment of two exotic invasive species in a semiarid ecosystem

Theory predicts that in more stressful environments, positive plant-plant interactions should be more important than negative ones. For instance, in arid and semiarid regions, amelioration of soil drought produced by the shade of established plants could facilitate establishment of other species, in spite of light reduction. However, this theory has not been tested widely in the context of plant invasion. In this paper we evaluated the hypothesis that in a semiarid ecosystem of central Chile, the native tree, Lithrea caustica, should facilitate through positive shading effects, the seedling establishment of two widely planted and invasive forestry species, Pinus radiata and Eucalyptus globulus. We assessed the seedling establishment examining two processes: seedling recruitment (including germination) and subsequent seedling survival. We sowed seeds (to assess recruitment) and planted 8 months old seedlings (to assess seedling survival) of each exotic species under Lithrea patches, open sites and under an artificial shade mimicking Lithrea shading. The study was repeated in a north-facing and a south-facing slope in the study area located in a xeric zone within the distribution range of plantations of these species in central Chile. Our results show that in a north-facing slope Lithrea had positive effects on recruitment of both species, which was produced by shading. These effects were counteracted by negative effects on seedling survival but through a different mechanism, which suggests that Lithrea would have no significant effect on the whole seedling establishment process of Pinus radiata nor Eucalyptus globulus in this habitat. In turn, in a south-facing slope Lithrea had no significant effect on recruitment but had a negative effect on seedling survival, which was not produced by shading. This suggests that in this habitat Lithrea has a negative effect on the seedling establishment of these exotic species. Our results suggest that the effect of the native Lithrea caustica on the seedling establishment of these exotic species is dependent upon the life-cycle phase (recruitment or seedling survival) and habitat even within the same semiarid ecosystem. In contrast to the expected positive effects Lithrea is unlikely to facilitate seedling establishment of these exotic species in this area, and in fact in some habitats this effect could be negative. However, our results also suggest that a common mechanism proposed to resist invasion in forest ecosystems such as shading, probably is not sufficient to inhibit invasion in a semiarid region.     

Monitoring the effects of <Emphasis Type="Italic">Rodolia cardinalis</Emphasis> on <Emphasis Type="Italic">Icerya purchasi</Emphasis> populations on the Galapagos Islands

In January 2002, the first biological control program was implemented on the Galapagos Islands with the release of the Australian coccinellid Rodolia cardinalis Mulsant to control the invasive cottony cushion scale, Icerya purchasi Maskell. This was the first time that Galapagos authorities had approved the introduction of a biological control agent to this iconic archipelago and, because of this precedent, it was important to monitor and evaluate its behaviour soon after its introduction. Surveys were carried out after the release of R. cardinalis in 2002 to confirm establishment on Santa Cruz Island. In 2009, seven years post-release, a broader survey was done to document spread throughout the archipelago. Directly after the release of R. cardinalis in 2002, a predator exclusion study and field observations were carried out on scale insect populations on white mangrove (Laguncularia racemosa [L.] Gaertn. F.) on Santa Cruz Island to document impact. In less than three months after R. cardinalis was released in 2002, populations of I. purchasi on white mangrove that were exposed to the predator in the exclusion experiment, or were monitored in the field, had declined by 99–100%. Results suggest that R. cardinalis played a key role in this decline, possibly in combination with high rainfall. Rodolia cardinalis dispersed quickly after its release and by 2009 was found in a wide variety of habitats on seven of the eight islands surveyed that had records of I. purchasi. Two of these were self-introductions. Further monitoring is recommended to determine whether this biological control agent has successfully reduced scale insect numbers on other valued plant species.     

Pathogénie comparée de 4 espèces d'Helminthosporium Obtenues à Partir des Plantes Malades du Riz au Maroc

A comparative study into the pathogenicity of four Helminthosporiumspp. towards rice cultivars in Marocco In this paper, the behaviour of four Helminthosporium species on nine rice cultivars widely cultivated in Morocco, permit the classification of this species according to their virulence. Helminthosporium oryzae and Helminthosporium sativum are the most virulent and the best equipped to sporule on all varieties of tested lesions. The level of pathogenicity of Helminthosporium spiciferum and Helminthosporium australiensis and their capacity to sporule on host plant depend on the rice variety used. At the same time, each Helminthosporium induces characteristics symptoms on rice leaves.     

Investigating the Role of 4‐Tert Butylpyridine in Perovskite Solar Cells

The majority of hole‐transporting layers used in n‐i‐p perovskite solar cells contain 4‐tert butylpyridine (tBP). High power‐conversion efficiencies and, in particular, good steady‐state performance appears to be contingent on the inclusion of this additive. On the quest to improve the steady state efficiencies of the carbon nanotube‐based hole‐transporter system, this study has found that the presence of tBP results in an extraordinary improvement in the performance of these devices. By deconstructing a prototypical device and investigating the effect of tBP on each individual layer, the results of this study indicate that this performance enhancement must be due to a direct chemical interaction between tBP and the perovskite material. This study proposes that tBP serves to p‐dope the perovskite layer and investigates this theory with poling and work function measurements.     

Biology, host specificity tests, and risk assessment of the sawfly Heteroperreyia hubrichi, a potential biological control agent of Schinus terebinthifolius in Hawaii

Heteroperreyia hubrichiMalaise (Hymenoptera: Pergidae), a foliagefeeding sawfly of Schinusterebinthifolius Raddi (Sapindales:Anacardiaceae), was studied to assess itssuitability as a classical biological controlagent of this invasive weed in Hawaii. No-choice host-specificity tests were conductedin Hawaiian quarantine on 20 plant species in10 families. Besides the target weed, adultfemales oviposited on four test species. Females accepted the Hawaiian native Rhussandwicensis A. Gray (Sapindales:Anacardiaceae) as an oviposition host equallyas well as the target species. The other threespecies received significantly fewer eggs. Neonate larvae transferred onto test plantssuccessfully developed to pupae on S.terebinthifolius (70% survival) and R.sandwicensis (1% survival). All other 18test plant species failed to support larvaldevelopment. A risk analysis was conducted toquantify the acceptability of non-targetspecies as host plants for H. hubrichi onthe basis of the insect's performance atvarious stages in its life cycle. Risk ofdamage to all plant species tested wasinsignificant except for R. sandwicensis. Risk to this native plant relative to S.terebinthifolius was estimated at 1%. Currently this level of risk is too high torequest introduction of this insect into theHawaiian environment. Detailed impact studiesin the native range of S. terebinthifoliusare needed to identify thepotential benefit that this insect offers. Also, field studies in South America withpotted R. sandwicensis would give a morereliable analysis of the risk this nativeHawaiian plant would face from naturalpopulations of H. hubrichi.     

A large number of tetraploid Arabidopsis thaliana lines, generated by a rapid strategy, reveal high stability of neo-tetraploids during consecutive generations

Arabidopsis thaliana has, in conjunction with A. arenosa, developed into a system for the molecular analysis of alloplolyploidy. However, there are very few Arabidopsis lines available to study autopolyploidy. In order to investigate polyploidy on a reliable basis, we have optimised conventional methodologies and developed a novel strategy for the rapid generation and identification of polyploids based on trichome branching patterns. The analysis of more than two dozen independently induced Arabidopsis lines has led to interesting observations concerning the relationship between cell size and ploidy levels and on the relative stability of tetraploidy in Arabidopsis over at least three consecutive generations. The most important finding of this work is that neo-tetraploid lines exhibit considerable stability through all the generations tested. The systematic generation of tetraploid collections through this strategy as well as the lines generated in this work will help to unravel the consequences of polyploidy, particularly tetraploidy, on the genome, on gene expression and on natural diversity in Arabidopsis. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Anin vitro rearing system for the propagation of the ectoparasitoidCatolaccus grandis

An experimental ‘closed’ rearing system, where egg and larval manipulations were eliminated, was developed for the in vitro rearing of Catolaccus grandis (Hymenoptera: Pteromalidae) Burks, an important ectoparasitoid of the cotton boll weevil, Anthonomus grandis Boheman. In this rearing model, n-hexane (a synthetic ovipositional stimulant for this parasitoid), was smeared on the Parafilm® cover of a modified rearing chamber (a Multiwell®) tissue culture plate) to induce the deposition of uncontaminated eggs, on the inner side of this waxy membrane, and on or around an agar retained diet that had been dispensed into the individual chamber wells. When the efficiency of the in vitro rearing system was compared to the current in vivo rearing method for this species, the duration of the life cycle was significantly shorter in parasitoids reared in vivo, but this difference was less than one day (17.8 vs 17.1 days, respectively). On the other hand, the number of eggs laid in the in vitro rearing chamber during a 4 h period was c. 2.5 times greater than in the conventional in vivo rearing apparatus, and adult yields were c. 25% greater when using the in vitro closed rearing method. Male to female ratios were c. 1:9 when reared in vitro as compared to 1.0:1.5 for those reared in vivo. There were no apparent adverse effects of this in vitro rearing system on the parasitoid's general behavior and reproduction after two consecutive generations.     

OBSERVATIONS ON CHYTRIDIACEOUS PARASITES OF PHANEROGAMS. XIX. A PHYSODERMA ON EURASIAN WATER MILFOIL (MYRIOPYLLUM SPICATUM)

A Physoderma was found on Myriophyllum spicatum in Michigan. This is the first recorded on this host from this hemisphere. It differs from the Danish P. myriophylli Rostrup in not producing galls on the host and in several aspects of its endobiotic stage. It more closely resembles a Swedish fungus attributed to Physoderma hippuridis by Lagerheim occurring on the same species of host.     

A new species of Acanthobothrium van Beneden, 1850 (Tetraphyllidea: Onchobothriidae) from Pastinachus atrus (Macleay) (Batoidea: Dasyatidae) in Australian waters, with a reassessment of the host associations of Acanthobothrium spp. parasitising Pastinachus spp

A new Category 1 species of Acanthobothrium van Beneden, 1850 is described from the cowtail stingray Pastinachus atrus (Macleay) collected from the Gulf of Carpentaria near Weipa, Queensland, Australia. This species is unique among Acanthobothrium Category 1 species in that it retains gravid proglottids on its strobila. It differs further from the 34 other Category 1 species in total length, proglottid number and testis number. The host identities of other Acanthobothrium species reported from Pastinachus are revised based on recent taxonomic work on rays of this genus. Given the revised host taxonomy, according to which P. atrus is the only member of its genus occurring off Australia, this should be considered to be the fifth species of Acanthobothrium reported from this Australian endemic species.     

The effect of heated effluent on the occurrence and the reproduction of the freshwater limpetsAncylus fluviatilis Müller, 1774,Ferrissia wautieri (Mirolli, 1960) andAcroloxus lacustris (L., 1758) in two Dutch water bodies

The discharge of cooling water favours the occurrence of freshwater limpets. Reproduction ofAncylus fluviatilis is stimulated by the higher temperature of the cooling water; the life cycle ofFerrissia wautieri (nearly exclusively found in the outlet areas) does not, however, differ from that under natural temperature regimes. ForAcroloxus lacustris this is not clear as detailed studies on the life cycle under natural temperature circumstances are lacking. Acroloxus lacustris andFerrissia wautieri could be found in large numbers on hard substrates (stones), as well as on plant material in sheltered as well as in exposed situations. In this respect they differ fromAncylus fluviatilis, which is restricted in its occurrence to hard substrates and exposed situations.It is not very clear whether the occurrence ofAncylus fluviatilis is also influenced by some form of competition for food byBithynia tentaculata; both feed on diatoms. Further experimental studies of this question should yield interesting results.The changes in numbers of the three freshwater limpet species are mainly due to reproduction and migration, both largely governed by temperature and day length.It was possible to reconstruct the influence of cooling water in the Bergumermeer area by means of the ratio between the numbers ofAcroloxus lacustris andFerrissia wautieri. The share ofFerrissia was highest near the outiet and decreased with the distance from this station.     

Biological Soil Crusts of Sand Dunes in Cape Cod National Seashore,Massachusetts, USA

Biological soil crusts cover hundreds of hectares of sand dunes at the northern tip of Cape Cod National Seashore (Massachusetts, USA). Although the presence of crusts in this habitat has long been recognized, neither the organisms nor their ecological roles have been described. In this study, we report on the microbial community composition of crusts from this region and describe several of their physical and chemical attributes that bear on their environmental role. Microscopic and molecular analyses revealed that eukaryotic green algae belonging to the genera Klebsormidium or Geminella formed the bulk of the material sampled. Phylogenetic reconstruction of partial 16S rDNA sequences obtained from denaturing gradient gel electrophoresis (DGGE) fingerprints also revealed the presence of bacterial populations related to the subclass of the Proteobacteria, the newly described phylum Geothrix/Holophaga/Acidobacterium, the Cytophaga/Flavobacterium/Bacteroides group, and spirochetes. The presence of these crusts had significant effects on the hydric properties and nutrient status of the natural substrate. Although biological soil crusts are known to occur in dune environments around the world, this study enhances our knowledge of their geographic distribution and suggests a potential ecological role for crust communities in this landscape.This revised version was published online in November 2004 with corrections to Volume 48.     

Sawadaea nankinensis comb. nov.: a powdery mildew fungus of Acer buergerianum

The anamorphic state of a powdery mildew on trident maple (Acer buergerianum, Aceraceae), belonging to Sawadaea, has been observed since 1980 in Tokyo and other areas of Japan. Since the autumn of 2003, this fungus has begun to produce chasmothecia in various areas of Japan, which were consistent with Erysiphe nankinensis (= Uncinula nankinensis), but apparently contradictory to the characteristics of the anamorph. Based on a molecular phylogenetic analysis using DNA separately extracted from the anamorph and teleomorph of the fungus on A. buergerianum, it could be demonstrated that sequences of this fungus are sister to Sawadaea. As the anamorph belongs to Oidium subgen. Octagoidium and because of the phylogenetic position within the Sawadaea clade, the new combination Sawadaea nankinensis is proposed for this species. The genus Sawadaea is emended to comprise species with consistently unbranched appendages.     

Insights Gained From 50 Years of Studying the Evolution of Self-Compatibility in <Emphasis Type="Italic">Leavenworthia</Emphasis> (Brassicaceae)

The shift from outcrossing to selfing is one of the most common evolutionary trends in plants, and there is intense interest in why this is so. The genus Leavenworthia has been the focus of research on this question for half of a century, with particular attention paid to the evolution of self-compatibility from self-incompatibility. In this review, we discuss the last 50 years of research concerning this evolutionary transition in Leavenworthia. Selfing appears to have evolved independently at minimum three times within this genus of eight species. Work on the ecological basis of mating system evolution in Leavenworthia has clarified that selection among individuals is likely a major force behind the recurrent evolution of selfing. Although inadequate pollination is appreciated as a factor favoring selfing, definitive ecological mechanisms that act to favor selfing are still not known and future work on the efficacy of pollinating bees and the effects of climate change is needed. Recent research has likely identified the SRK ortholog at the S-locus controlling self-incompatibility in Leavenworthia alabamica. Analyses of S-locus variation have revealed substantial S-allele diversity in outcrossing populations, with the recurrent fixation of mutations at the S-locus permitting the parallel evolution of selfing in this species. Although we appreciate some of the factors that may explain the evolution of selfing in this group, there is less known about the mechanisms underlying the widespread maintenance of outcrossing at the population and species levels. Studies in Leavenworthia have revealed that genetic diversity is lost over the long-term within selfing populations and leads to elevated population subdivision, but work is needed to determine why these genetic consequences of selfing cause lineages to become evolutionary dead ends.     

Search for effective natural enemies of Tetranychus evansi in south and southeast Brazil

Tetranychus evansi Baker & Pritchard is an important pest of Solanaceae in several countries. Introduced accidentally to Africa, it presently occurs in many countries of that continent. In some of them, it is considered a key pest. The suspected area of origin of this mite is South America. The objective of the present study was to identify phytoseiid mites on solanaceous plants in association with T. evansi in south and southeast Brazil for introduction in the African continent for use in a classic biological control program. Almost 1,400 predatory mites of the family Phytoseiidae were collected, on 22 solanaceous species. The Amblyseiinae were the most diverse group in this study. Twenty-three of the species found belong to this subfamily, while only three belong to the Typhlodrominae and two to the Phytoseiinae. The most abundant and most frequent phytoseiid species were Phytoseius guianensis De Leon and Galendromus annectens (De Leon) of the Phytoseiinae and Typhlodrominae, respectively. The most frequent and abundant species of Amblyseiinae was Neoseiulus tunus (De Leon). Phytoseius guianensis and N. tunus were never found in association with T. evansi and G. annectens was found only once in association with it. Two factors suggested Phytoseiulus longipes Evans as the most promising predator found in this study. It could walk very well on tomato leaves infested by T. evansi, without being hampered by the profuse webbing produced by the prey and by the trichomes. In addition, several specimens of both sexes including eggs and nymphs of the predator were found associated with T. evansi on three different plant species and in two different periods of the year, when T. evansi was the only arthropod present on the leaves.     

The protein N-glycosylation in plants

In plants, most of the extracellular compartment and the endomembrane system are glycosylated by N-linked oligosaccharides. The N-glycosylation of proteins has a great impact both on their physicochemical properties and on their biological functions. Over the last ten years, a number of laboratories have contributed considerably to the structure, the biosynthesis and the function of plant N-linked glycans. In this review, data on this domain will be summarized and the recent results on the N-glycosylation of a vacuolar lectin, the bean phytohaemagglutinin (PHA) will also be included. This PHA, used as a model glycoprotein, was expressed in different plant systems and the N-glycosylation patterns of different recombinant PHA were compared. In addition to this study on plant-specific glycosylation, the same model glycoprotein was used to investigate whether or not N-glycosylation and N-glycan maturation is organ-specific in plants.Keywords: N-linked oligosaccharide, biosynthesis and function, phytohaemagglutinin.      

Incidence of and risks associated with <Emphasis Type="Italic">Giardia</Emphasis> infections in herds on dairy farms in the New York City Watershed

Background  

The primary aims of this study were to determine the incidence of Giardia infections in dairy herds on farms in the New York City Watershed region and to evaluate risk factors associated with infections. Because co-infections of Giardia and Cryptosporidium spp. are common in this population, we also evaluated the effect of herd infection status on Giardia infections.     

<Emphasis Type="Italic">Aurifilum,</Emphasis> a new fungal genus in the Cryphonectriaceae from <Emphasis Type="Italic">Terminalia</Emphasis> species in Cameroon

Native Terminalia spp. in West Africa provide a popular source of construction timber as well as medical, spiritual and social benefits to rural populations. Very little is, however, known regarding the diseases that affect these trees. During an investigation into possible diseases of Terminalia spp. in Cameroon, orange to yellow fungal fruiting structures, resembling those of fungi in the Cryphonectriaceae, were commonly observed on the bark of native Terminalia ivorensis, and on dead branches of non-native Terminalia mantaly. In this study the fungus was identified based on morphological features as well as DNA sequence data (ITS and β-tubulin) and its pathogenicity was tested on T. mantaly seedlings. Our results showed that isolates of this fungus represent a previously undescribed genus in the Cryphonectriaceae, which we describe as Aurifilum marmelostoma gen. et sp. nov. Pathogenicity tests revealed that A. marmelostoma is pathogenic on T. mantaly. These tests, and the association of A. marmelostoma with disease symptoms on T. ivorensis, suggest that the fungus is a pathogen of this important tree.