Core alpha1,3-fucose is a key part of the epitope recognized by antibodies reacting against plant N-linked oligosaccharides and is present in a wide variety of plant extracts

Carbohydrates have been suggested to account for some IgE cross- reactions between various plant, insect, and mollusk extracts, while some IgG antibodies have been successfully raised against plant glycoproteins. A rat monoclonal antibody raised against elderberry abscission tissue (YZ1/2.23) and rabbit polyclonal antiserum against horseradish peroxidase were screened for reactivity in enzyme-linked immunosorbent assay against a range of plant glycoproteins and extracts as well as neoglycoproteins, bee venom phospholipase, and several animal glycoproteins. Of the oligosaccharides tested, Man3XylFucGlcNAc2(MMXF3) derived from horseradish peroxidase was the most potent inhibitor of the reactivity of both YZ1/2.23 and anti- horseradish peroxidase to native horseradish peroxidase glycoprotein. The reactivity of YZ1/2. 23 and anti-horseradish peroxidase against Sophora japonica lectin was most inhibited by a neoglycoconjugate of bromelain glycopeptide cross-linked to bovine serum albumin, while the defucosylated form of this conjugate was inactive as an inhibitor. A wide range of plant extracts was found to react against YZ1/2.23 and anti-horseradish peroxidase, with particularly high reactivities recorded for grass pollen and nut extracts. All these reactivities were inhibitable with the bromelain glycopeptide/bovine serum albumin conjugate. Bee venom phospholipase and whole bee venom reacted weakly with YZ1/2.23 but more strongly with anti-horseradish peroxidase in a manner inhibitable with the bromelain glycopeptide/bovine serum albumin conjugate, while hemocyanin from Helix pomatia reacted poorly with YZ1/2.23 but did react with anti-horseradish peroxidase. It is concluded that the alpha1, 3-fucose residue linked to the chitobiose core of plant glycoproteins is the most important residue in the epitope recognized by the two antibodies studied, but that the polyclonal anti-horseradish peroxidase antiserum also contains antibody populations that recognize the xylose linked to the core mannose of many plant and gastropod N-linked oligosaccharides.      

Cleavase Fragment Length Polymorphism (CFLP): A Methodology to Further Exploit Polymorphisms from PCR Products of Plastid DNA (ptDNA) in Phaseolus

The CFLP methodology was applied for Cleavase I site detection within ptDNA intergenic regions (atpB-rbcL and rps14-psaB) at both interspecific and intraspecific levels in the genus Phaseolus. Optimal Cleavase I reaction temperature was 55°C and the semi-dry electrophoretic transfer was more efficient than the original capillary one. Cleavase reactions yield a high number of fragments as compared to PCR-RFLP and allowed differentiation within and between landraces and wild forms of the Lima bean (Phaseolus lunatus L.) originating from Andean and Mesoamerican regions of Latin America. From sequencing data and using stemloop program (GCG, Madison), congruent numbers of hairpins/fragments were identified within the sequences, highlighting the robustness of the Cleavase I. Our results pointed out the ubiquity of short conserved motifs amongst a geographically localized group of species. In the vicinity of these motifs, synapomorphic-like substitutions were frequently observed. A phylogenetic tree based on these sequences is congruent with the CFLP pattern as well as with the widely accepted phylogeny of the genus. The usefulness of this new tool as alternative and/or complementary to PCR-RFLP technology on ptDNA is suggested and discussed.     

Direct evidence for Ca2+ regulation of hyphal branch induction

Grinberg, A., and Heath, I. B. 1997. Direct evidence for Ca2+ regulation of hyphal branch induction. 22, 127-139. Irradiation of growing hyphae of Saprolegnia ferax with microbeams of UV (300-380 and 385-450 nm) light induced an increase in cytoplasmic [Ca2+] followed by precocious formation of one or more branches within about 4 min. The distribution of branches was strongly skewed toward the subapical side of the irradiation site, but otherwise was apparantly random. Apical (10-&mgr;m) irradiations were more effective than subapical (50-&mgr;m) ones in that they induced branches at comparable frequencies but with lower doses, consistent with higher concentrations of putative target intracellular Ca2+ storage structures in this region. Once formed, induced adjacent branches seem to compete for "resources," with those closer than approximately 50 &mgr;m inhibiting each other. The results are most consistent with Ca2+-induced accumulation of branch initiating factors being the cause, not the consequence, of branch formation, thus supporting a primary role for Ca2+ in regulation of hyphal tip growth. Copyright 1997 Academic Press. Copyright 1997 Academic Press     

Actin Disruption by Latrunculin B Causes Turgor-Related Changes in Tip Growth of Saprolegnia ferax Hyphae

Hyphae of Saprolegnia ferax growing under normal or low-turgor conditions were exposed to 0.1-10 &mgr;g/ml latrunculin B, an actin inhibitor. In the first 10 s of addition, hyphae with normal turgor levels accelerated while those with low turgor decelerated, consistent with the suggestion that actin restrains or protrudes tips under these respective turgor conditions. Both sets of hyphae then decelerated and eventually ceased extension within 60 s. These changes were reflected in rhodamine-phalloidin staining patterns, which showed that actin caps were disrupted progressively under both conditions in a time-dependent manner. After 60 s, normal-turgored hyphae started to swell rapidly while low-turgored hyphae showed little or no swelling. Swelling was characteristically subapical, which is best explained by tip growth models which incorporate actin-mediated exocytosis.     

Genetic analyses using GGE model and a mixed linear model approach,and stability analyses using AMMI bi-plot for late-maturity alpha-amylase activity in bread wheat genotypes

Low falling number and discounting grain when it is downgraded in class are the consequences of excessive late-maturity α-amylase activity (LMAA) in bread wheat (Triticum aestivum L.). Grain expressing high LMAA produces poorer quality bread products. To effectively breed for low LMAA, it is necessary to understand what genes control it and how they are expressed, particularly when genotypes are grown in different environments. In this study, an International Collection (IC) of 18 spring wheat genotypes and another set of 15 spring wheat cultivars adapted to South Dakota (SD), USA were assessed to characterize the genetic component of LMAA over 5 and 13 environments, respectively. The data were analysed using a GGE model with a mixed linear model approach and stability analysis was presented using an AMMI bi-plot on R software. All estimated variance components and their proportions to the total phenotypic variance were highly significant for both sets of genotypes, which were validated by the AMMI model analysis. Broad-sense heritability for LMAA was higher in SD adapted cultivars (53%) compared to that in IC (49%). Significant genetic effects and stability analyses showed some genotypes, e.g. ‘Lancer’, ‘Chester’ and ‘LoSprout’ from IC, and ‘Alsen’, ‘Traverse’ and ‘Forefront’ from SD cultivars could be used as parents to develop new cultivars expressing low levels of LMAA. Stability analysis using an AMMI bi-plot revealed that ‘Chester’, ‘Lancer’ and ‘Advance’ were the most stable across environments, while in contrast, ‘Kinsman’, ‘Lerma52’ and ‘Traverse’ exhibited the lowest stability for LMAA across environments.     

Evaluation of cholesteryl ester transfer in the seminiferous tubule cells of immature rats in vivo and in vitro

Sertoli cells and germ cells are separated from the interstitial blood capillaries by an extracellular matrix and the peritubular cells, which constitute a barrier to the movement of plasma lipoproteins. The present study was undertaken to evaluate in vivo and in vitro the high density lipoprotein (HDL) cholesteryl ester transfer from plasma to seminiferous tubule cells in the testis of 30-day-old rats. Firstly, the transfer of HDL cholesteryl oleate from plasma to testicular compartments was evaluated and, secondly, the role of apolipoproteins A-I and E in the uptake of cholesteryl ester by Sertoli cells was investigated. At 2 h after the administration of HDL reconstituted with [3H]cholesteryl ester, dimyristoyl phosphatidylcholine and apolipoproteins, the tissue space in the interstitial cells (740 +/- 60 microliters g-1 cell protein) was fourfold higher than that in the seminiferous tubule cells (170 +/- 10 microliters g-1). Sertoli cells were isolated and incubated with [3H]cholesteryl ester HDL reconstituted with apolipoprotein A-I or E to evaluate the mechanisms of cholesteryl ester influx. At the same apolipoprotein concentration (50 micrograms apolipoprotein ml-1 medium), the uptake of [3H]cholesteryl oleate from phospholipid-apolipoprotein E vesicles was twofold higher than that with phospholipid-apolipoprotein A-I vesicles. The presence of heparin reduced the uptake of cholesteryl ester from apolipoprotein E vesicles but not with apolipoprotein A-I vesicles, indicating that uptake of apolipoprotein A-I vesicles via a secretion of apolipoprotein E by the cells themselves was not involved. These results demonstrate that plasma lipoprotein cholesterol is able to cross the testis lamina propria and that Sertoli cells take up cholesteryl ester for seminiferous tubule cell metabolism mainly via an apolipoprotein E pathway.     

The impact of researcher disturbance on nest predation rates: a meta‐analysis

The effects of visits to nests by researchers interested in quantifying avian nesting success have received considerable attention, as researchers have long been concerned about the possible negative effects of their own activities on the resulting estimates. There is a widely held view that investigator disturbance has an overall negative effect on breeding success by increasing nest predation rates in the nests studied. However, to date no one has statistically assessed the empirical evidence for such a relationship. We undertook a meta‐analysis of published results to assess whether researcher activities increase nest predation in birds. We also assessed the variability in this effect in relation to the traits of the study species and the methodology used. These analyses used data from 18 experimental studies involving 25 species from six avian orders. Our results suggest that, contrary to the traditional view, researcher activities do not generally affect the incidence of nest predation. Moreover, this relationship appears inconsistent among avian orders and, surprisingly, nest survival of passerines increased weakly with researcher activities. We also found significant positive effects of researcher activity on nest survival for species breeding on coastal areas and for species nesting on the ground. The possible explanation for these differences among orders and guilds could be due to different nest predator communities. This new perspective on the effect of investigators could have important implications for bird management and conservation, as well as for other fields of study such as ecology and evolution, in which nest survival rates measured in the field are widely used to test and support a range of hypotheses.     

Screening for acute childhood malnutrition during the National Nutrition Week in mali increases treatment referrals

Objective

To evaluate a pilot intervention designed to integrate mid-upper arm circumference (MUAC) screening for acute malnutrition into the semi-annual Child Nutrition Week (Semaine d''Intensification des Activités de Nutrition, or “SIAN”) activities carried out in June 2008.

Design

A cross-sectional survey was conducted in Kolokani and Nara, two health districts in the Koulikoro region of Mali, 4–5 months after the SIAN, using a population-proportionate, multi-stage random sample of: 1) health centers, and 2) households in communities linked to each of the selected health centers. Caregivers of 1543 children who were 6–59 months of age at the time of the SIAN, 17 community-based volunteers and 45 health center staff members were interviewed.

Results

A total of 1278 children 6–59 months (83% of those studied) reportedly participated in SIAN. Of the participating children, 1258 received vitamin A (98% of SIAN participants; 82% of all eligible children), 945 received anti-helminth tablets (84% of participants; 71% of eligibles), and 669 were screened for acute malnutrition (52% of participants; 43% of eligibles). 186 of the children screened (27%) were reportedly identified as acutely malnourished. SIAN screening covered a significantly greater proportion of children than were examined in both community-based (22% of children) and health center-based screening activities (5% of children) combined during the 4-5 months after the SIAN (P<0.0001). In general, community volunteers and health personnel positively evaluated their experience adding MUAC screening to SIAN.

Conclusion

Integrating MUAC screening for acute malnutrition in SIAN permits the assessment of a large number of children for acute malnutrition, and should be continued.     

Evidence for subdivision within the M molecular form of Anopheles gambiae

The principal vector of malaria in sub-Saharan Africa, Anopheles gambiae is subdivided into two molecular forms M and S. Additionally, several chromosomal forms, characterized by the presence of various inversion polymorphisms, have been described. The molecular forms M and S each contain several chromosomal forms, including the Savanna, Mopti and Forest forms. The M and S molecular forms are now considered to be the reproductive units within A. gambiae and it has recently been argued that a low recombination rate in the centromeric region of the X chromosome has facilitated isolation between these forms. The status of the chromosomal forms remains unclear however. Therefore, we studied genetic differentiation between Savanna S, Forest S, Forest M and Mopti M populations using microsatellites. Genetic differentiation between Savanna S and Forest S populations is very low (F(ST) = 0.0053 +/- 0.0049), even across large distances. In comparison, the Mopti M and Forest M populations show a relatively high degree of genetic differentiation (F(ST) = 0.0406 +/- 0.0054) indicating that the M molecular form may not be a single entity, but could be subdivided into at least two distinct chromosomal forms. Previously it was proposed that inversions have played a role in the origin of species within the A. gambiae complex. We argue that a possible subdivision within the M molecular form could be understood through this process, with the acquisition of inversions leading to the expansion of the M molecular form into new habitat, dividing it into two distinct chromosomal forms.