Hydrophylita (Lutzimicron) emporos Shih & Polaszek (Hymenoptera: Trichogrammatidae) from Taiwan,Parasitising Eggs,and Phoretic on Adults,of the Damselfly Psolodesmus mandarinus mandarinus (Zygoptera: Calopterygidae)

Hydrophylita emporos n. sp. reared from eggs of Psolodesmus mandarinus mandarinus McLachlan (Zygoptera: Calopterygidae) in Taiwan is described. This is the first species of Hydrophylita to be described from the Old World, and the first record of phoresy in the genus. Adult females were observed aggregating at the base of the female damselfly’s abdomen. When the damselfly begins ovipositing, females move to the tip of the abdomen, enter the water and quickly locate eggs for parasitising. The article contains links to video footage of this process.     

Ancestral gene duplications in mosses characterized by integrated phylogenomic analyses

Mosses (Bryophyta) are a key group occupying an important phylogenetic position in land plant (embryophyte) evolution. The class Bryopsida represents the most diversified lineage, containing more than 95% of modern mosses, whereas other classes are species‐poor. Two branches with large numbers of gene duplications were elucidated by phylogenomic analyses, one in the ancestry of all mosses and another before the separation of the Bryopsida, Polytrichopsida, and Tetraphidopsida. The analysis of the phylogenetic progression of duplicated paralogs retained on genomic syntenic regions in the Physcomitrella patens genome confirmed that the whole‐genome duplication events WGD1 and WGD2 were re‐recognized as the ψ event and the Funarioideae duplication event, respectively. The ψ polyploidy event was tightly associated with the early diversification of Bryopsida, in the ancestor of Bryidae, Dicranidae, Timmiidae, and Funariidae. Together, four branches with large numbers of gene duplications were unveiled in the evolutionary past of P. patens. Gene retention patterns following the four large‐scale duplications in different moss lineages were analyzed and discussed. Recurrent significant retention of stress‐related genes may have contributed to their adaption to distinct ecological environments and the evolutionary success of this early‐diverging land plant lineage.     

First fossil fruits of Elaeocarpus (Elaeocarpaceae) in East Asia: Implications for phytogeography and paleoecology

The genus Elaeocarpus contains approximately 360 species and occurs in mesic forest communities from India, through to China, Southeast Asia, New Guinea, Australia, and New Caledonia. Elaeocarpus fossils are best known from the Eocene to the Miocene of Australia and the late Pliocene–early Pleistocene of India, but have not been documented from East Asia before. Here we describe six new species of Elaeocarpus, E. nanningensis sp. nov. from the late Oligocene Yongning Formation of the Nanning Basin, E. presikkimensis sp. nov. from the Miocene Erzitang Formation of the Guiping Basin, E. prerugosus sp. nov., E. prelacunosus sp. nov., E. preserratus sp. nov., and E. preprunifolioides sp. nov. from the late Miocene Foluo Formation of the Nankang Basin in Guangxi, South China. This is the first reliable report for the genus occurring in East Asia, and the fossils indicate that Elaeocarpus had colonized this region by the late Oligocene and represented by a morphologically diverse group of species by the late Miocene. This sheds new insights into the timing and migration patterns of the genus in East Asia. Elaeocarpus is typically a rainforest genus occurring in mesic forests. Based on the habitat of their morphologically similar modern relatives we propose that these three sedimentary basins were warm and wet adjacent to mountainous regions with the evergreen or rain forests during the late Oligocene to Miocene.     

The effects of foliar pubescence and nutrient enrichment on arthropod communities of Metrosideros polymorpha (Myrtaceae)

Abstract.  1. Nutrient resource availability and host-plant foliar pubescence both influence arthropod food webs, but multifactor studies are needed to understand their interdependence and relative importance. Arthropods were sampled by clipping foliage from Metrosideros polymorpha (Myrtaceae) trees of pubescent, glabrous, and intermediate leaf forms on fertilised and unfertilised plots.
2. Fertilisation decreased leaf mass per area (LMA) but did not change the relative mass of pubescence within leaf morphological classes.
3. Fertilisation increased densities of individuals in four taxonomic orders, densities of individuals and species of all trophic levels, and the biomass of Collembola and Homoptera. Herbivore relative diversity (Shannon H ') also increased with fertilisation, but detritivore diversity declined due to increasing dominance of Salina celebensis (Schaeffer) (Collembola).
4. Detritivore density, driven again by S. celebensis , increased with decreasing leaf pubescence, but Heteroptera and Acari were most abundant on the intermediate pubescence class, and Psocoptera density and biomass increased with increasing pubescence. Trophic-level species density did not change with leaf morphological class, but relative diversity of all arthropods and of detritivores increased with increasing pubescence.
5. Both resource availability and leaf pubescence affected Metrosideros arthropod communities. However, the pervasive positive influence of fertilisation did not translate to compositional shifts, and there were no interactions with leaf morphological class. In contrast, the effects of leaf pubescence on arthropod density, biomass, and diversity were more restricted taxonomically, and non-parametric manova and redundancy analyses demonstrated significant differentiation in community composition on the pubescent morphology.     

The spatial dynamics of pollen beetles in relation to inflorescence growth stage of oilseed rape: implications for trap crop strategies

Semi‐field‐scale arrays of oilseed rape (Brassica napus L.) (Brassicaceae) plants were used to observe the development of distributions of pollen beetles (Meligethes aeneus Fabricius) (Coleoptera: Nitidulidae) in a simulated trap crop system where inflorescence growth stage alone was used to manipulate the pest. Over two successive years, pairs of 1 m spaced square arrays of 100 glasshouse‐grown plants were placed 40 m apart in the field in May, and were subject to natural infestation by pollen beetles. The test plot of each pair had a simulated trap crop, with an outer row of plants at early flowering stage intended to protect more susceptible inner plants at late bud stage, and the control plot had all plants at the late‐bud stage, simulating a standard crop situation. Pollen beetles were counted daily on each plant for 10–13 days. The spatio‐temporal development of plot infestation was analysed in relation to the distribution of racemes in bud and raceme in flowers using Spatial Analysis by Distance IndicEs (SADIE), and tests of edge and centre distribution. Inflorescence growth stage characteristics were shown to be important in determining the spatial distributions of pollen beetles. In control plots, the numbers of racemes in bud and in flower were never edge or centre distributed. In test plots, racemes in flower were always edge distributed, and racemes in bud began edge distributed and became centre distributed. Pollen beetle numbers were usually spatially associated with the abundance of racemes in bud and/or in flower. In control plots, pollen beetles were neither edge nor centre distributed, but in test plots they maintained a significant edge distribution for 7–10 days. At the end of the experiments, females were more centre distributed in the test plots than males, and were more closely associated with racemes with buds, whereas males were more associated with racemes with flowers. In early flowering stage plants, the number of racemes in flowers were a good indicator of the abundance of racemes in buds, but this relationship was lost as flowering progressed. Although flowering racemes provide strong cues for immigrating pollen beetles, the abundance of buds may be a more important determinant of residence time, particularly for females, and is therefore a critical determinant of trap crop effectiveness.     

Genetic structure of the stonefly, Yoraperla brevis, populations: the extent of gene flow among adjacent montane streams

1. Gene flow in populations of stream insects is expected to depend on the distance between and the connectedness of sites in stream networks, and on dispersal ability (i.e. larval drift and adult flight).
2. Yoraperla brevis (Banks) is an abundant and characteristic stonefly of smaller streams in the northern Rocky Mountains. The present authors analysed genetic structure at 27 sites in sevenz streams flowing into the Bitterroot River in western Montana, USA. Cellulose acetate electrophoresis identified five variable loci with 16 alleles.
3. Genotype frequencies conformed to Hardy–Weinberg expectations. Within-stream differentiation was low and among-stream variation ( F _st) was an order of magnitude higher.
4. UPGMA grouped sites within streams and also grouped adjacent streams. The tree produced by the Neighbour Joining Method was similar although not quite so clear cut.
5. This orderly pattern (i.e. Hardy–Weinberg proportions, homogeneity within streams and geographical structure) contrasts strongly with patterns observed in invertebrates from subtropical streams in Australia. Yoraperla brevis maintains large populations in predictable environments, has a long life-cycle with a likelihood of cohort mixing, emerges synchronously in large breeding populations and occupies streams separated by areas of high relief; the Australian situation is the opposite in most respects.
6. Further analysis of a range of species is required to determine whether the different genetic structure in Y. brevis compared to the Australian species occurs more generally in North American stream insects.     

Rapid Activation of Tyrosine Hydroxylase in Response to Nerve Growth Factor

Abstract: Nerve growth factor protein (NGF) was found to rapidly promote the activation of tyrosine hydroxylase in cultured rat PC 12 pheochromocytoma cells. PC 12 cultures were exposed to NGF for periods of less than 1 h and the soluble contents of homogenates prepared from the cells were assayed for tyrosine hydroxylase activity. Under these conditions, the specific enzymatic activity was increased by 60 ± 10% (n = 13) in comparison with that in untreated sister cultures. The increase was half maximal by 2–5 min of exposure and at NGF concentrations of about 10 ng/ml (0.36 n M ). Antiserum against NGF blocked the effect. Tyrosine hydroxylase activity could also be rapidly increased by NGF in cultures of PC12 cells that had been treated with the factor for several weeks in order to produce a neuron-like phenotype. This was achieved by withdrawing NGF for about 4 h and then readding it for 30 min. The NGF-induced increase of tyrosine hydroxylase activity in PC12 cultures was not affected by inhibition of protein synthesis and therefore appeared to be due to activation of the enzyme. Kinetic experiments revealed that NGF brought about no change in the apparent K_m of the enzyme for tyrosine or for co-factor (6-methyltetrahydropteridine), but that it did significantly increase the apparent maximum specific activity of the enzyme. These observations suggest that NGF (perhaps released by target organs) could promote a rapid and local enhancement of noradrenergic transmission in the sympathetic nervous system.     

An improved method of plant megabase DNA isolation in agarose microbeads suitable for physical mapping and YAC cloning

The isolation of high quality megabase DNA from plant cells that is susceptible to a variety of molecular reagents is a critical first step in the physical analysis of complex genomes. A method for the isolation of such DNA by encapsulating plant protoplasts in agarose microbeads is presented. In comparison with the conventional agarose plug method, microbeads provide a dramatic increase in the surface area yielding megabase DNA that can be treated essentially as an aqueous DNA solution. Examples of the utility of DNA prepared by this technique for physical mapping, partial restriction enzyme digestion and cloning of large inserts as YACs are presented.     

Genetic regulation of gibberellin deactivation in Pisum

The regulation of gibberellin (GA) deactivation was examined using the sin (slender) mutation in the garden pea (Pisum sativum L.). This mutation blocks the deactivation of GA₂₀, the precursor of the bioactive GA₁. Firstly, crosses were made to combine sin with the GA biosynthesis mutations na, lhⁱ and le-3. The combination sin na produced a novel phenotype, with long (‘slender’) basal internodes and extremely short (‘nana’) upper internodes. In contrast, the double mutant sin lhⁱ was phenotypically dwarf. The mutation sin causes an accumulation of GA₂₀ in maturing seeds, and this was unaffected by na, since the na mutation is not expressed in seeds. In contrast, lhⁱ seeds did not accumulate GA₂₀, since lhⁱ imposes an early block on GA biosynthesis. Secondly, the effects of sin on several steps in GA deactivation were investigated. In maturing seeds, the mutation sin blocks two steps in GA₂₀ metabolism, namely, GA₂₀ to GA₂₉, and GA₂₉ to GA₂₉-catabolite. In the vegetative plant, on the other hand, sin blocked the step GA₂₀ to GA₂₉, but not GA₂₉ to GA₂₉-catabolite; the steps GA₂₀ to GA₈₁ and GA₂₀ to GA₁ were also not impaired in this mutant. It is clear that the effects of sin, like those of na, are strongly organ-specific. The presence of separate enzymes for the steps GA₂₀ to GA₂₉ and GA₂₉ to GA₂₉-catabolite was suggested by the observation that GA₈ inhibited the latter step, but not the former, and by the inability of GA₂₀ and GA₂₉ to inhibit each other's metabolism. It is suggested that the Sin gene may be a regulatory gene controlling the expression of two structural genes involved in GA deactivation.     

α-Synuclein modulation of Ca2+ signaling in human neuroblastoma (SH-SY5Y) cells

Parkinson's disease (PD) is characterized in part by the presence of α-synuclein (α-syn) rich intracellular inclusions (Lewy bodies). Mutations and multiplication of the α-synuclein gene ( SNCA ) are associated with familial PD. Since Ca²⁺ dyshomeostasis may play an important role in the pathogenesis of PD, we used fluorimetry in fura-2 loaded SH-SY5Y cells to monitor Ca²⁺ homeostasis in cells stably transfected with either wild-type α-syn, the A53T mutant form, the S129D phosphomimetic mutant or with empty vector (which served as control). Voltage-gated Ca²⁺ influx evoked by exposure of cells to 50 mM K⁺ was enhanced in cells expressing all three forms of α-syn, an effect which was due specifically to increased Ca²⁺ entry via L-type Ca²⁺ channels. Mobilization of Ca²⁺ by muscarine was not strikingly modified by any of the α-syn forms, but they all reduced capacitative Ca²⁺ entry following store depletion caused either by muscarine or thapsigargin. Emptying of stores with cyclopiazonic acid caused similar rises of [Ca²⁺]_i in all cells tested (with the exception of the S129D mutant), and mitochondrial Ca²⁺ content was unaffected by any form of α-synuclein. However, only WT α-syn transfected cells displayed significantly impaired viability. Our findings suggest that α-syn regulates Ca²⁺ entry pathways and, consequently, that abnormal α-syn levels may promote neuronal damage through dysregulation of Ca²⁺ homeostasis.