Addition of terpenoids to pear ester plus acetic acid increases catches of codling moth (Lepidoptera: Tortricidae)

Field studies were conducted to evaluate new kairomone blends in combination with pear ester (E,Z)‐2,4‐ethyl decadienoate (PE) and acetic acid (AA) for their attraction of male and female codling moth, Cydia pomonella (L.), in apple, Malus domestica Borkhausen. The addition of decanal to either AA or PE alone significantly increased total and female moth catches. However, the addition of decanal did not improve the attraction of PE + AA. The addition of either the pyranoid (PyrLOX) or furanoid (FurLOX) linalool oxide but not linalool (LOL) increased moth catches with PE but did not increase catches with PE + AA. Similarly, the addition of PyrLOX plus decanal did not improve PE + AA. The addition of (E)‐4,8‐dimethyl‐1,3,7‐nonatriene (DMNT) to either AA, PE + AA or PE + AA+decanal did not significantly increase moth catches. However, the addition of PyrLOX to traps with PE + AA and DMNT (4‐component lure) significantly increased moth catches compared with PE + AA alone or any of the ternary blends of these volatiles. Females accounted for 60%–80% of the total catch with this 4‐component lure. The 4‐component blend with PyrLOX was a more attractive lure than similar blends that substituted LOL, or a binary blend of LOL and FurLOX for PyrLOX. The 4‐component blend caught nearly fourfold more total and female moths than the purported attractant N‐butyl sulphide when it was used in combination with PE + AA. These results indicate that significant improvements in monitoring, mating disruption and mass trapping of codling moth are possible. Further studies are needed to assess the new attractive blend's effectiveness in combination with sex pheromone lures and to evaluate whether other host plant volatiles can be added or substitute for DMNT or LOX when used in combination with PE + AA.     

基于DNA弯曲度的H2A.Z核小体定位与修饰研究

在真核生物染色质中,H2A.Z是高度保守的组蛋白变异体,与转录调控、基因组的稳定性密切相关。为了探讨组蛋白修饰、DNA弯曲度与H2A.Z核小体定位三者之间的关联,在得到实验所测的相关数据后,利用MINE算法并结合皮尔逊相关系数在酵母全基因组的转录起始位点周围探讨了三者间的线性与非线性关系。其中MIC算法可以定量的得出数据之间关联度大小的值,用于衡量数据之间是否存在着关联,而皮尔逊相关系数则用于检查是否为线性关联。结果除了发现大部分组蛋白修饰种类和核小体定位之间存在着线性关联外,还探测到有两种组蛋白修饰数据(H4ac修饰与GCN4修饰)和核小体定位数据之间存在着以往未发现的非线性关系(大致呈正余弦函数),并从数据的生物背景(组蛋白修饰与核小体位置)上探讨了出现非线性现象的原因。     

Loss of the gene for the alpha subunit of ATP synthase (ATP5A1) from the W chromosome in the African grey parrot (Psittacus erithacus)

This study describes the results of an analysis using Southern blotting, the polymerase chain reaction, and sequencing which shows that the African grey parrot (Psittacus erithacus) lacks the W-chromosomal gene for the alpha subunit of mitochondrial ATP synthase (ATP5A1W). Additional evidence shows that in other psittacines a fragment of the ATP5A1W gene contains five times as many nonsynonymous nucleotide replacements as the homologous fragment of the Z gene. Therefore, whereas in these other psittacines the corresponding ATP5A1Z protein fragment is highly conserved and varies by only a few, moderately conservative amino acid substitutions, the homologous ATP5A1W fragments contain a considerable number of, sometimes highly nonconservative, amino acid replacements. In one of these species, the ringneck parakeet (Psittacula krameri), the ATP5A1W gene is present in an inactive form because of the presence of a nonsense codon. Other changes, possibly leading to an inactive ATP5A1W gene product, involve the substitution of arginine residues by cysteine in the ATP5A1W protein of the mitred conure (Aratinga mitrata) and the blue and gold macaw (Ara ararauna). The data suggest also that although the divergence of the psittacine ATP5A1W and ATP5A1Z genes preceeded the origin of the psittacidae, this divergence occurred independently of a similar process in the myna (Gracula religiosa), the outgroup used in this study. Received: 6 September 2000 / Accepted: 7 March 2001     

Antilisterial activity of lactic acid bacteria isolated from rigouta, a traditional Tunisian cheese

AIMS: Screening for lactic acid bacteria (LAB) producing bacteriocins and other antimicrobial compounds is of a great significance for the dairy industry to improve food safety. METHODS AND RESULTS: Six-hundred strains of LAB isolated from 'rigouta', a Tunisian fermented cheese, were tested for antilisterial activity. Eight bacteriocinogenic strains were selected and analysed. Seven of these strains were identified as Lactococcus lactis and produced nisin Z as demonstrated by mass spectrometry analysis of the purified antibacterial compound. Polymerase chain reaction experiments using nisin gene-specific primers confirmed the presence of nisin operon. Plasmid profiles analysis suggests the presence of, at least, three different strains in this group. MMT05, the eighth strain of this antilisterial collection was identified, at molecular level, as Enterococcus faecalis. The purified bacteriocin produced by this strain showed a molecular mass of 10 201.33 +/- 0.85 Da. This new member of class III bacteriocins was termed enterocin MMT05. CONCLUSIONS: Seven lactococcal strains producing nisin Z were selected and could be useful as bio-preservative starter cultures. Additional experiments are needed to evaluate the promising strain MMT05 as bio-preservative as Enterococci could exert detrimental or beneficial role in foods. SIGNIFICANCE AND IMPACT OF THE STUDY: Only a few antibacterial strains isolated from traditional African dairy products were described. The new eight strains described herein contribute to the knowledge of this poorly studied environment and constitute promising strains for fermented food safety.     

Study of caspase inhibitors for limiting death in mammalian cell culture

Apoptosis in mammalian cell culture is associated with decreased bioproduct yields and can be inhibited through altering the intracellular signaling pathways mediating programmed cell death. In this study, we evaluated the capacity to inhibit caspases to maintain high viable cell numbers in CHO and 293 cultures. Two genetic caspase inhibitors, XIAP and CrmA, were examined along with a mutant of each, XIAP-BIR123NC, which contains three BIR domains but lacks the RING finger, and CrmA-DQMD, which has CrmA's pseudosubstrate site replaced with that of another caspase inhibitor, p35. Stable CHO pooled and 293 clonal cell lines expressing each protein were exposed to apoptotic insults, including spent medium, Sindbis virus, and etoposide. For each insult the mutated protein resulted in higher viabilities than its wild-type counterpart. However, the mutants provided different levels of protection, depending on the insult considered. CrmA-DQMD was the preferred inhibitor for spent medium-induced apoptosis, whereas XIAP-BIR123NC conferred better protection for etoposide-induced death. Addition of Z-VAD.fmk to the genetically engineered cells enhanced viabilities in the presence of spent medium or etoposide; however, the largest increases in viability were experienced by the control cells, indicating an overlap in caspase inhibition between the genetic and chemical inhibitors. Finally, parental 293 cells were treated with caspase-8 and -9 inhibitors, Z-IETD.fmk and Z-LEHD.fmk, in concert with spent medium or etoposide exposure. Spent medium-induced death was delayed more readily with the caspase-8 inhibitors, CrmA-DQMD and Z-IETD.fmk, and etoposide-induced death was stalled more so with XIAP-BIR123NC and Z-LEHD.fmk. These results suggest that the apoptosis pathways induced and the level of protection afforded by a particular caspase inhibitor may vary with the insult considered.     

Coupling of antibodies via protein Z on modified polyoma virus-like particles

Therapeutic application of virus-based delivery systems often implies a change of the tropism of these vectors. This can be achieved by insertion of polypeptides (e.g., antibody fragments) in viral coat proteins. Such fusion proteins have only been used in viral vectors so far and, as part of a virus, they have not been available for a detailed biophysical characterization. We analyzed a fusion protein called VP1-Z, which is based on the polyoma virus coat protein VP1 and protein Z. Protein Z is an engineered antibody-binding domain derived from protein A from Staphylococcus aureus. The fusion VP1-Z was constructed by insertion of protein Z in the HI-loop of VP1. As wild-type VP1, VP1-Z formed pentameric capsomers and assembled to VLPs in vitro. The stability of these particles was very similar compared to that of VLPs of wild-type VP1. Protein Z was fully structured in the fusion protein and was still capable of binding antibodies on the surface of VLPs of VP1-Z. Using this fusion protein, we could change the tropism of polyoma VLPs toward cells presenting on their surface the antigen of the coupled antibody.     

Prevalence of zinc deficiency in junior high school students of Tehran City

Zinc deficiency is a health problem in many communities especially among adolescents because of pubertal growth sprout. This investigation was carried out to determine the epidemiology of zinc deficiency in junior high school students in Tehran City in 1997. This cross-sectional study was performed on 881 students (452 males and 429 females) with the mean age of 13.2±1.0 yr, who were selected by multistage random sampling method. Plasma, erythrocyte, and hair zinc levels were assayed by flame atomic absorption spectrophotometry. Anthropometric and demographic characteristics were measured and recorded on a questionnaire. Dietary intakes were evaluated by a 24-h recall method. Zinc deficiency was defined as having at least two indices from indices of erythrocyte, plasma, and hair zinc below 10 μg/mL, 100 μg/dL, and 125 μg/g of hair, respectively. The results showed that zinc deficiency prevalence was 31.1% (confidence interval: 28–34.4%). Zinc deficiency was 65%, 49%, and 1.3% based on plasma, erythrocyte, and hair zinc levels, respectively. The mean ± SD for plasma, erythrocyte, and hair zinc concentration, height-for-age, as well as weight-for-age Z scores were 95.2±17.7 μg/dL, 10.3±2.3 μg/mL, 239.4±54.4 μg/g, −0.40±0.92, and 0.12±0.91, respectively. As for dietary intake compared with the RDA, 50% of the subjects consumed less than 50% of their requirement for zinc RDA based on a 24-h dietary recall. Zinc intake in subjects was 7.5±3.7 μg, that in boys was higher than in girls. Correlation coefficients between zinc status indices were very weak. There was neither a linear nor nonlinear relationship between biochemical parameters and nutritional zinc intake. It is concluded that almost one-third to one-half of the subjects would be considered zinc deficient.     

Semiochemicals from ovaries of gravid females attract ovipositing female houseflies,Musca domestica

Chemical signals originating from the ovaries of gravid females of Musca domestica (Diptera: Cyclorrhapha: Muscidae) attract ovipositing females to common egg-laying sites. Behavioral experiments indicated that females preferred to oviposit in fermented wheat bran containing ovaries from reproductively mature houseflies. Females preferred to oviposit in fermented wheat bran than wet wheat bran. This effect was additive with the attraction to housefly ovaries. Solvent extracts from housefly ovaries were attractive to gravid females. Extracts obtained with hexane were most attractive to gravid females for egg laying, and extracts obtained with ethyl acetate attracted more egg laying than extracts obtained by dichloromethane. Gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS) analysis showed that tricosane and (Z)-9-tricosene were the main components of the hexane extracts. Both tricosane and (Z)-9-tricosene were shown to elicit dose-dependent aggregation of gravid females in oviposition bioassays, but high doses of either chemical were not attractive.     

The tubulin ancestor,FtsZ, draughtsman,designer and driving force for bacterial cytokinesis

We discuss in this review the regulation of synthesis and action of FtsZ, its structure in relation to tubulin and microtubules, and the mechanism of polymerization and disassembly (contraction) of FtsZ rings from a specific nucleation site (NS) at mid cell. These topics are considered in the light of recent immunocytological studies, high resolution structures of some division proteins and results indicating how bacteria may measure their mid cell point.