Invertebrate biodiversity affects predator fitness and hence potential to control pests in crops

Natural enemies that control pests usually allow farmers to avoid, or reduce, the use of pesticides. However, modern farming practices, that maximize yields, are resulting in loss of biodiversity, particularly prey diversity. Does this matter? Pests continue to thrive, and without alternative prey the predators should, perforce, concentrate their attentions upon the pests.We showed that a diverse diet significantly enhances predator fecundity and survival. Experiments were conducted using common generalist predators found in arable fields in Europe, the carabid beetle Pterostichus melanarius (Coleoptera: Carabidae) and the linyphiid spider Erigone atra (Araneae: Linyphiidae). We tested the hypothesis that mixed species diets were optimal, compared with restricted diets, with respect to parameters such as predator weights, egg weights, numbers of eggs laid, egg development times, egg hatching rates and predator survival. In carabids, an exclusive earthworm diet was as good as mixed diets containing earthworms for egg production and hatching, but less good than such mixed diets for increase in beetle mass and sustained egg laying. For spiders, aphids alone (Sitobion avenae) or with the Collembola Folsomia candida, drastically reduced survival. Aphids plus the Collembola Isotoma anglicana improved survival but only aphids with a mixed Collembola diet maximized numbers of hatching eggs.Predators offered only pests (slugs or aphids) had lowest growth rates and fecundity. We therefore demonstrated that conservation of a diversity of prey species within farmland, allowing predators to exploit a diverse diet, is essential if predators are to continue to thrive in crops and regulate agricultural pests.     

The use of proteome similarity for the qualitative and quantitative profiling of reperfused myocardium

An LC-MS-based approach is presented for the identification and quantification of proteins from unsequenced organisms. The method relies on the preservation of homology across species and the similarity in detection characteristics of proteomes in general. Species related proteomes share similarity that progresses from the amino acid frequency distribution to the complete amino sequence of matured proteins. Moreover, the comparative analysis between theoretical and experimental proteome distributions can be used as a measure for the correctness of detection and identification obtained through LC-MS-based schemes. Presented are means to the identification and quantification of rabbit myocardium proteins, immediately after inducing cardiac arrest, using a data-independent LC-MS acquisition strategy. The employed method of acquisition affords accurate mass information on both the precursor and associated product ions, whilst preserving and recording the intensities of the ions. The latter facilitates label-free quantification. The experimental ion density observations obtained for the rabbit sub proteome were found to share great similarity with five other mammalian samples, including human heart, human breast tissue, human plasma, rat liver and a mouse cell line. Redundant, species-homologues peptide identifications from other mammalian organisms were used for initial protein identification, which were complemented with peptide identifications of translated gene sequences. The feasibility and accuracy of label-free quantification of the identified peptides and proteins utilizing above mentioned strategy is demonstrated for selected cardiac rabbit proteins.     

Proteomic analysis of multidrug‐resistance mechanisms in adriamycin‐resistant variants of DLKP,a squamous lung cancer cell line

Alterations in protein expression associated with adriamycin resistance in a panel of variants derived from the poorly differentiated squamous cell lung carcinoma DLKP were investigated using 2‐D DIGE. Of the 80 proteins identified as being differentially expressed, 32 correlated to adriamycin resistance. Twenty‐four proteins showed positive correlations with drug resistance, 11 correlated directly with increase in the resistance (including NDPK, RPA2, CCT2, HSP70 and Annexin A1) while 13 proteins (including HNRP K and H1, aldehyde dehydrogenase (ALDH), stomatin and CCT3) increased to a similar level in all drug‐resistant variants. Fewer proteins showed an inverse correlation with resistance; two (protein disulphide isomerase (PDI) and HSP70 variant 1) displayed a similar decrease in all variants and six (including prohibitin (PHB) and EIF5A) correlated inversely with resistance. Three proteins (EEF1D, Actin G1 and Annexin 1) correlated with the invasive status of these variants. Some expected targets of adriamycin action showed correlation with resistance including RPA2 (critical for DNA damage repair), while others proteins involved in protection from ROS production (such as GST, peroxiredoxins and thioredoxins) did not. The proteomic analysis revealed a large number of changes in protein expression that may contribute to a more apoptosis‐resistant state. Many of these changes could provide novel targets for overcoming resistance.     

Re-establishing a saltmarsh vegetation structure in a changing climate

Summary A major management decision in an ecological restoration or rehabilitation project is whether supplementary planting or natural vegetation regeneration is the better alternative or if a combination can be applied. Management decisions are further complicated when the project involves saltmarsh as tidal cycles, the effects of salinity and sea level rise add to the complexity of decisions. The ecological values of the saltmarsh community in Australia were only recognized relatively recently but the endangered ecological community listing in 1994 (under the New South Wales Threatened Species Conservation Act 1995) highlighted the need to protect, rehabilitate and restore saltmarsh. This project measured vegetation change after soil profile reconstruction in saltmarsh surrounding Sponsors Lagoon, Fingal Peninsula in north coastal New South Wales, Australia. Restored sites (planted and non‐planted) were compared with nearby disturbed (control) and reference sites. The dominant species in the community to be restored were Saltwater Couch (Sporobolus virginicus), Suaeda (Suaeda australis), Sarcocornia (Sarcocornia quinqueflora ssp. quinqueflora and Sea Rush (Juncus kraussii ssp. australiensis). Changes in percentage cover of the species in the first three years after soil reconstruction work showed that the dominant Saltwater Couch established only from vegetative growth arising from remnant vegetation but there was strong seedling regeneration of several other species. It was concluded that planting is important for species that are less vagile, in larger, denuded parts of this site where their resilience is lower and natural regeneration potential is limited. An understanding of the biology of the individual species is therefore likely to be essential in saltmarsh restoration projects. A combination of techniques, incorporating planting of slower establishing species and encouragement of seed‐germinated colonizers is useful for initial site stabilization and progressive ecological recovery at this site. The inclusion of migration zones in the planning phase will allow for the long‐term viability of this restoration project.     

Phosphatidylinositol 3′-kinase signalling supports cell height in established epithelial monolayers

Cell–cell interactions influence epithelial morphogenesis through an interplay between cell adhesion, trafficking and the cytoskeleton. These cellular processes are coordinated, often by cell signals found at cell–cell contacts. One such contact-based signal is the phosphatidylinositol 3′-kinase (PI3-kinase; PI3K) pathway. PI3-kinase is best understood for its role in mitogenic signalling, where it regulates cell survival, proliferation and differentiation. Its precise morphogenetic impacts in epithelia are, in contrast, less well-understood. Using phosphoinositide-specific biosensors we confirmed that E-cadherin-based cell–cell contacts are enriched in PIP₃, the principal product of PI3-kinase. We then used pharmacologic inhibitors to assess the morphogenetic impact of PI3-kinase in MDCK and MCF7 monolayers. We found that inhibiting PI3-kinase caused a reduction in epithelial cell height that was reversible upon removal of the drugs. This was not attributable to changes in E-cadherin expression or homophilic adhesion. Nor were there detectable changes in cell polarity. While Myosin II has been implicated in regulating keratinocyte height, we found no effect of PI3-kinase inhibition on apparent Myosin II activity; nor did direct inhibition of Myosin II alter epithelial height. Instead, in pursuing signalling pathways downstream of PI3-kinase we found that blocking Rac signalling, but not mTOR, reduced epithelial cell height, as did PI3-kinase inhibition. Overall, our findings suggest that PI3-kinase exerts a major morphogenetic impact in simple cultured epithelia through preservation of cell height. This is independent of potential effects on adhesion or polarity, but may occur through PI3-kinase-stimulated Rac signaling.     

High-Density SNP Screening of the Major Histocompatibility Complex in Systemic Lupus Erythematosus Demonstrates Strong Evidence for Independent Susceptibility Regions

A substantial genetic contribution to systemic lupus erythematosus (SLE) risk is conferred by major histocompatibility complex (MHC) gene(s) on chromosome 6p21. Previous studies in SLE have lacked statistical power and genetic resolution to fully define MHC influences. We characterized 1,610 Caucasian SLE cases and 1,470 parents for 1,974 MHC SNPs, the highly polymorphic HLA-DRB1 locus, and a panel of ancestry informative markers. Single-marker analyses revealed strong signals for SNPs within several MHC regions, as well as with HLA-DRB1 (global p = 9.99×10⁻¹⁶). The most strongly associated DRB1 alleles were: *0301 (odds ratio, OR = 2.21, p = 2.53×10⁻¹²), *1401 (OR = 0.50, p = 0.0002), and *1501 (OR = 1.39, p = 0.0032). The MHC region SNP demonstrating the strongest evidence of association with SLE was rs3117103, with OR = 2.44 and p = 2.80×10⁻¹³. Conditional haplotype and stepwise logistic regression analyses identified strong evidence for association between SLE and the extended class I, class I, class III, class II, and the extended class II MHC regions. Sequential removal of SLE–associated DRB1 haplotypes revealed independent effects due to variation within OR2H2 (extended class I, rs362521, p = 0.006), CREBL1 (class III, rs8283, p = 0.01), and DQB2 (class II, rs7769979, p = 0.003, and rs10947345, p = 0.0004). Further, conditional haplotype analyses demonstrated that variation within MICB (class I, rs3828903, p = 0.006) also contributes to SLE risk independent of HLA-DRB1*0301. Our results for the first time delineate with high resolution several MHC regions with independent contributions to SLE risk. We provide a list of candidate variants based on biologic and functional considerations that may be causally related to SLE risk and warrant further investigation.     

Contralateral effects of unilateral strength training: evidence and possible mechanisms.

If exercises are performed to increase muscle strength on one side of the body, voluntary strength can increase on the contralateral side. This effect, termed the contralateral strength training effect, is usually measured in homologous muscles. Although known for over a century, most studies have not been designed well enough to show a definitive transfer of strength that could not be explained by factors such as familiarity with the testing. However, an updated meta-analysis of 16 properly controlled studies (range 15-48 training sessions) shows that the size of the contralateral strength training effect is approximately 8% of initial strength or about half the increase in strength of the trained side. This estimate is similar to results of a large, randomized controlled study of training for the elbow flexors (contralateral effect of 7% initial strength or one-quarter of the effect on the trained side). This is likely to reflect increased motoneuron output rather than muscular adaptations, although most methods are insufficiently sensitive to detect small muscle contributions. Two classes of central mechanism are identified. One involves a "spillover" to the control system for the contralateral limb, and the other involves adaptations in the control system for the trained limb that can be accessed by the untrained limb. Cortical, subcortical and spinal levels are all likely to be involved in the "transfer," and none can be excluded with current data. Although the size of the effect is small and may not be clinically significant, study of the phenomenon provides insight into neural mechanisms associated with exercise and training.     

Molecular Ecology Of Macrolide–Lincosamide–Streptogramin B Methylases in Waste Lagoons and Subsurface Waters Associated with Swine Production

RNA methylase genes are common antibiotic resistance determinants for multiple drugs of the macrolide, lincosamide, and streptogramin B (MLS_B) families. We used molecular methods to investigate the diversity, distribution, and abundance of MLS_B methylases in waste lagoons and groundwater wells at two swine farms with a history of tylosin (a macrolide antibiotic structurally related to erythromycin) and tetracycline usage. Phylogenetic analysis guided primer design for quantification of MLS_B resistance genes found in tylosin-producing Streptomyces (tlr(B), tlr(D)) and commensal/pathogenic bacteria (erm(A), erm(B), erm(C), erm(F), erm(G), erm(Q)). The near absence of tlr genes at these sites suggested a lack of native antibiotic-producing organisms. The gene combination erm(ABCF) was found in all lagoon samples analyzed. These four genes were also detected with high frequency in wells previously found to be contaminated by lagoon leakage. A weak correlation was found between the distribution of erm genes and previously reported patterns of tetracycline resistance determinants, suggesting that dissemination of these genes into the environment is not necessarily linked. Considerations of gene origins in history (i.e., phylogeny) and gene distributions in the landscape provide a useful “molecular ecology” framework for studying environmental spread of antibiotic resistance.     

A narrow group of monophyletic Tulasnella (Tulasnellaceae) symbiont lineages are associated with multiple species of Chiloglottis (Orchidaceae): Implications for orchid diversity

? Premise of the study: The Orchidaceae is characterized by exceptional species diversity. Obligate orchid mycorrhizae are predicted to determine orchid distributions, and highly specific relationships between orchids and fungi may drive orchid diversification. In this study, mycorrhizal diversity was examined in the terrestrial, photosynthetic orchid genus Chiloglottis to test the hypothesis of mycorrhizal-mediated diversification in the genus Chiloglottis. This orchid genus secures pollination by sexual deception, an obligate and highly specific pollination strategy. Here we asked whether the obligate orchid-fungal interactions are also specific. ? Methods: Two sequenced loci, the internal transcribed spacer region (ITS) and mitochondrial large subunit (mtLSU), were used to identify fungal isolates and assess fungal species diversity. Symbiotic germination of two species Chiloglottis aff. jeanesii and C. valida were used to assess germination potential of isolates and confirm mycorrhizal association. ? Key results: Phylogenetic analyses revealed that six representative Chiloglottis species spanning a broad survey of the genus were all associated with a narrow group of monophyletic Tulasnella fungal lineages. ? Conclusions: The Chiloglottis-Tulasnella interaction appears to be the first known case of such a narrow symbiont association across a broadly surveyed orchid genus. It appears that the specific pollination system of Chiloglottis, rather than specific orchid-fungal interactions has been the key driving force in the diversification of the genus. These findings also indicate that plant groups with highly specific mycorrhizal partners can have a widespread distribution.