Dispersal of the broad mite,Polyphagotarsonemus latus (Banks) (Heterostigmata: Tarsonemidae), by the greenhouse whitefly,Trialeurodes vaporariorum (Westwood) (Homoptera: Aleyrodidae)

The greenhouse whitefly, Trialeurodes vaporariorum (Westwood), (Homoptera: Aleyrodidae) was found to disperse the broad mite, Polyphagotarsonemus latus (Banks) (Heterostigmata: Tarsonemidae). Mite presence on whiteflies was highly aggregated. This is the second whitefly species reported to disperse the broad mite, suggesting some recognition of the insects by P. latus.     

Lectin binding pattern and band 3 localization in toad skin epithelium and the effect of salt acclimation

Seven lectins were employed to localize glycoconjugates in the skin of a toad (Bufo viridis). Each of the lectins exhibited a particular, specific and selective binding pattern. Peanut lectin (PNA) and WGA bound to mitochondria-rich (MR) cells, but WGA bound also abundantly, in the dermis. Band 3-like protein, as indicated by the reaction with polyclonal anti band 3 antibody, was localized exclusively in MR cells. Ionic acclimation (200 mmol/L NaCl, or 50 mmol/L KCl) affected profoundly the binding pattern of the lectins. High NaCl acclimation resulted also in diminishing anti band 3 antibody binding, whereas in skins of KCl-acclimated toads the staining remained similar to the control. The binding of WGA but not PNA, corresponded with the same cells that stained with anti band 3 antibody. PNA in concentration of < 10 μg/mL reduced reversibly, both the resting and activated Cl^? conductance by 25–30%. Based on differential binding of band 3, WGA and PNA, these observations provide conclusive verification of the presence of at least two populations of MR cells in the toad skin epithelium. It is suggested that the PNA positive MR cells may correspond to a β-type MR cell. The information can be used to study molecular mechanisms that are involved in ionic acclimation.     

Localization of a Band 3-related protein in the mitochondria-rich cells of amphibian skin epithelium

Based on immunoblotting procedure, the isolated epithelium of amphibian skin was found to contain a 180 kDa protein which cross-reacts with a polyclonal antiserum raised against human erythrocyte Band 3. Immunoperoxidase and immunofluorescence staining techniques indicated that the Band 3-related protein was localized in the mitochondria-rich cells (MRC) of this epithelium, with characteristic apical labelling pattern. Our findings show that the putative apical anion exchanger of the MRC is immunologically related to the band 3 multigenic family, which catalyzes Cl-HCO₃ ^? transmembranous exchange. It thus suggests a molecular basis for the role played by these cells in the transepithelial Cl pathway and acid-base regulation.     

The C2B Domain Is the Primary Ca Sensor in DOC2B: A Structural and Functional Analysis

DOC2B (double-C₂ domain) protein is thought to be a high-affinity Ca^2 + sensor for spontaneous and asynchronous neurotransmitter release. To elucidate the molecular features underlying its physiological role, we determined the crystal structures of its isolated C2A and C2B domains and examined their Ca^2 +-binding properties. We further characterized the solution structure of the tandem domains (C2AB) using small-angle X-ray scattering. In parallel, we tested structure–function correlates with live cell imaging tools. We found that, despite striking structural similarity, C2B binds Ca^2 + with considerably higher affinity than C2A. The C2AB solution structure is best modeled as two domains with a highly flexible orientation and no difference in the presence or absence of Ca^2 +. In addition, kinetic studies of C2AB demonstrate that, in the presence of unilamellar vesicles, Ca^2 + binding is stabilized, as reflected by the ~ 10-fold slower rate of Ca^2 + dissociation than in the absence of vesicles. In cells, isolated C2B translocates to the plasma membrane (PM) with an EC₅₀ of 400 nM while the C2A does not translocate at submicromolar Ca^2 + concentrations, supporting the biochemical observations. Nevertheless, C2AB translocates to the PM with an ~ 2-fold lower EC₅₀ and to a greater extent than C2B. Our results, together with previous studies, reveal that the C2B is the primary Ca^2 + sensing unit in DOC2B, whereas C2A enhances the interaction of C2AB with the PM.     

Examining reluctance and emotional support in forensic interviews with child victims of substantiated physical abuse

Socio-emotional dynamics were examined in 230 forensic interviews of 3- to -13-year-old Israeli children who disclosed chronic physical abuse that could be substantiated. Half of the children were interviewed using the Standard (SP) National Institute of Child Health and Human Development Protocol and the others using the Revised Protocol (RP) that emphasized emotional support from interviewers. When children disclosed physical abuse in the RP interviews, they did so in response to fewer prompts than children in the SP interviews. The number of turns in the transitional phase (during which the interviewer transitioned from rapport-building to exploring the possibility of abuse) was associated with increased directness and more specific utterance types. The younger children displayed reluctance more than older children. The RP interviews were characterized by more emotionally supportive statements throughout. These findings highlight various aspects of child forensic interviews that should be considered when seeking to understand children’s willingness to engage with interviewers.     

Enzymic glycosphingolipid synthesis on polymer supports.

Two synthetic approaches leading toN-4-carboxymethyl-2-nitrobenzyloxycarbonyl derivatives of model compounds and of glycosylsphingosines are described. The carboxymethyl group can be converted into a hydrazido derivative and the resulting products react with an active ester polymer yielding light-sensitive polymeric products that may subsequently serve as acceptors in glycosyltransferase reactions.Author for correspondence. Address until September 1990; Graduate Department of Biochemistry, Brandeis University, 415 South Street, Waltham, MA 02254, USA     

Elevated CO2 and nitrate levels increase wheat root-associated bacterial abundance and impact rhizosphere microbial community composition and function

Elevated CO₂ stimulates plant growth and affects quantity and composition of root exudates, followed by response of its microbiome. Three scenarios representing nitrate fertilization regimes: limited (30 ppm), moderate (70 ppm) and excess nitrate (100 ppm) were compared under ambient and elevated CO₂ (eCO₂, 850 ppm) to elucidate their combined effects on root-surface-associated bacterial community abundance, structure and function. Wheat root-surface-associated microbiome structure and function, as well as soil and plant properties, were highly influenced by interactions between CO₂ and nitrate levels. Relative abundance of total bacteria per plant increased at eCO₂ under excess nitrate. Elevated CO₂ significantly influenced the abundance of genes encoding enzymes, transporters and secretion systems. Proteobacteria, the largest taxonomic group in wheat roots (~ 75%), is the most influenced group by eCO₂ under all nitrate levels. Rhizobiales, Burkholderiales and Pseudomonadales are responsible for most of these functional changes. A correlation was observed among the five gene-groups whose abundance was significantly changed (secretion systems, particularly type VI secretion system, biofilm formation, pyruvate, fructose and mannose metabolism). These changes in bacterial abundance and gene functions may be the result of alteration in root exudation at eCO₂, leading to changes in bacteria colonization patterns and influencing their fitness and proliferation.Subject terms: Microbiome, Microbial ecology, Metagenomics, Microbial ecology     

Modifier theory of meiotic drive: Is Mendelian segregation stable?

The evolutionary fate of rare modifiers, based on the modifier theory of meiotic drive, is studied in this paper. It is shown that a polymorphism based on Mendelian segregation is never stable for any recombination frequencies between 0 and $\text{1}\text{2}$, and that, for tight linkage between the main locus and the modifier locus, the modifier locus tends towards heterozygosity.