TEXshade: shading and labeling of multiple sequence alignments using LATEX2 epsilon

MOTIVATION: Typesetting, shading and labeling of nucleotide and peptide alignments using standard word processing or graphics software is time consuming. Available automatic sequence shading programs usually do not allow manual application of additional shadings or labels. Hence, a flexible alignment shading package was designed for both calculated and manual shading, using the macro language of the scientific typesetting software LATEX2 epsilon. RESULTS: TEXshade is the first TEX-based alignment shading software featuring, in addition to standard identity and similarity shading, special modes for the display of functional aspects such as charge, hydropathy or solvent accessibility. A plenitude of commands for manual shading, graphical labels, re-arrangements of the sequence order, numbering, legends etc. is implemented. Further, TEXshade allows the inclusion and display of secondary structure predictions in the DSSP-, STRIDE- and PHD-format. AVAILABILITY: From http://homepages.uni-tuebingen.de/beitz/tse.h tml (macro package and on-line documentation) CONTACT: eric.beitz@uni-tuebingen.de     

(E160A)和(E160D)天花粉蛋白两种突变体晶体结构研究

培养了（Ｅ１６０Ａ）ＴＣＳ和（Ｅ１６０Ｄ）ＴＣＳ的单晶。在ＭＡＲＲｅｓｅａｒｃｈ面探测器系统上分别收集了０．１９３ｎｍ和０．２０ｎｍ分辨率的Ｘ射线衍射数据。数据处理用ＭＡＲＳＣＡＬＥ程序系统完成。用同晶差值Ｆｏｕｒｉｅｒ法解析了突变体的晶体结构,结构修正利用Ｘ－ＰＬＯＲ程序。修正结果,晶体学Ｒ因子分别为０．１７５,０．１７９,键长和键角的ＲＭＳ偏差分别为０．００１１ｎｍ和２．４５７°,０．００１３ｎｍ和２．６７５°。在这两个突变体的结构中均未见到Ｇｌｕ１８９侧链方向的改变。通过对（Ｅ１６０Ａ）ＴＣＳ和（Ｅ１６０Ｄ）ＴＣＳ的结构比较,说明（Ｅ１６０Ｄ）ＴＣＳ活性低于（Ｅ１６０Ａ）ＴＣＳ的原因：这可能是由于在（Ｅ１６０Ｄ）ＴＣＳ中Ｔｙｒ１１１和Ｔｙｒ７０的侧链都具有较大的运动性,使它们与腺嘌呤碱基的芳香堆垛作用减弱,从而导致活性的降低     

Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) eggs as alternative food for rearing of lady beetles Eriopis connexa (Germar) (Coleoptera: Coccinellidae)

Eriopis connexa (Germar) (Coleoptera: Coccinellidae) is an important predator with potential for biological control of insect pests. This research evaluated the development of E. connexa larvae fed on fresh eggs of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) without (T1) or with (T2) scales or one-day (T3) or six-month (T4) frozen, or newly-hatched larvae of S. frugiperda (T5). The percentage of E. connexa adults was higher when larvae feeding on fresh S. frugiperda eggs with or without scales, or one-day frozen eggs of this prey and lower with eggs of this Lepidoptera after frozen for six months or with newly-hatched larvae of S. frugiperda. Duration of the larval period of E. connexa was 15.7, 15.8, 16.0, 17.6, and 17.3 days, respectively, with these diets. The high survival of E. connexa fed with eggs of S. frugiperda shows the potential use of this prey in the laboratory to maintain this natural enemy.     

Mucosal T lymphocyte numbers are selectively reduced in integrin alpha E (CD103)-deficient mice.

The mucosal lymphocyte integrin alpha E(CD103)beta 7 is thought to be important for intraepithelial lymphocyte (IEL) localization or function. We cloned the murine integrin gene encoding alpha E, localized it to chromosome 11, and generated integrin alpha E-deficient mice. In alpha E-/- mice, intestinal and vaginal IEL numbers were reduced, consistent with the known binding of alpha E beta 7 to E-cadherin expressed on epithelial cells. However, it was surprising that lamina propria T lymphocyte numbers were diminished, as E-cadherin is not expressed in the lamina propria. In contrast, peribronchial, intrapulmonary, Peyer's patch, and splenic T lymphocyte numbers were not reduced in alpha E-deficient mice. Thus, alpha E beta 7 was important for generating or maintaining the gut and vaginal T lymphocytes located diffusely within the epithelium or lamina propria but not for generating the gut-associated organized lymphoid tissues. Finally, the impact of alpha E deficiency upon intestinal IEL numbers was greater at 3-4 wk of life than in younger animals, and affected the TCR alpha beta+ CD8+ T cells more than the gamma delta T cells or the TCR alpha beta+ CD4+CD8- population. These findings suggest that alpha E beta 7 is involved in the expansion/recruitment of TCR alpha beta+ CD8+ IEL following microbial colonization. Integrin alpha E-deficient mice will provide an important tool for studying the role of alpha E beta 7 and of alpha E beta 7-expressing mucosal T lymphocytes in vivo.     

The species of the Enicospilus americanus complex (Hymenoptera: Ichneumonidae) in eastern North America

The Enicospilus americanus species-complex is characterized and a key presented to the seven eastern North American species. Three species, E.americanus (Christ), E.glabratus (Say) and E.texanus (Ashmead) are redescribed, and four species are described as new. These are: E. lebophagus sp.n., a Mesoamerican species whose range just extends into southern Texas; E.cushmani sp.n., a widespread eastern North American species, E.aktites sp.n., a Mesoamerican coastal species whose range extends into the very southern tip of Florida; and E.peigleri sp.n., a northern Mexican/southern U.S. species. The cephalic capsules of the final instar larvae of five species are described, and notes on the biology of all species presented. The known hosts of the species are listed.  

Resumen

Se caracteriza el complejo de especies Enicospilus americanus y se presenta una Have para las siete especies del este de Norte America. Se redescriben tres especies: E.americanus (Christ), E.glabratus (Say) y E.texanus (Ashmead) y cuatro se describen como nuevas: E.lebophagus , una especie mesoamericana cuya distribution apenas se extiende hasta el sur de Texas; E.cushmani , especie muy distribuida en el este norte-americano; E.aktites , una especie mesoamericana cuya distribucion apenas se extiende hasta el sur de Florida; y E.peigleri , especies del norte de Mexico y sur de los Estados Unidos. Se describen las capsulas cefalicas del instar final de larva de cinco especies y se presentan algunas notas sobre la biologia de todas las especies, asi como tambien una lista con todos los huespedes conocidos de las especies.     

Investigation of de novo cholesterol synthetic capacity in the gonads of goldfish (Carassius auratus) exposed to the phytosterol beta-sitosterol

Total and intra-mitochondrial gonadal cholesterol concentrations are decreased in fish exposed to the phytoestrogen beta-sitosterol (beta-sit). The present study examined the potential for beta-sit to disrupt de novo cholesterol synthesis in the gonads of goldfish exposed to 200 microgram/g beta-sit and 10 microgram/g 17beta-estradiol (E2; estrogenic control) by intra-peritoneal Silastic^® implants for 21 days. The de novo cholesterol synthetic capacity was estimated by incubating gonadal tissue with 14C-acetate for a period of 18 hours, followed by chloroform/methanol lipid extraction and thin layer chromatography (TLC) lipid separation. Lipid classes were confirmed using infrared spectroscopy. Plasma testosterone (T) and total cholesterol concentration were measured and gonadosomatic index (GSI) was calculated. Plasma T was significantly reduced in male beta-sit-treated fish compared to control and E2-treated fish (p < 0.001). 14C-Acetate incorporation into cholesterol and cholesterol esters was not significantly different among treatment groups for male and female fish, however, 14C-enrichment was higher than expected in both triglycerides (TG) and free fatty acids (FFA). FFA incorporation was significantly higher in male control fish than either beta-sit or E2 treatments (p = 0.005). Plasma cholesterol concentration was significantly increased in the male beta-sit treatment group compared to controls (p = 0.027). These results indicate gonadal de novo cholesterol biosynthetic capacity is not disrupted by beta-sit or E2 treatment in early recrudescing male or female goldfish, while plasma cholesterol and steroid concentrations are sensitive to beta-sit exposure.     

Organization of cytoplasmic domains of sarcoplasmic reticulum Ca(2+)-ATPase in E(1)P and E(1)ATP states: a limited proteolysis study

In order to characterize the domain organization of sarcoplasmic reticulum Ca(2+)-ATPase in different physiological states, limited proteolysis using three proteases (proteinase K (prtK), V8 and trypsin) was conducted systematically and quantitatively. The differences between E(2) and E(2)P were examined in our previous study and E(2)P was characterized by the complete resistance to all three proteases (except for trypsin attack at the very top of the molecule (T1 site)). The same strategies were employed in this study for E(1)ATP, E(1)PADP and E(1)P states. Because of the transient nature of these states, they were either stabilized by non-hydrolyzable analogues or made predominant by adjusting buffer conditions. Aluminum fluoride (without ADP) was found to stabilize E(1)P. All these states were characterized by strong (E(1)ATP) to complete (E(1)PADP and E(1)P) resistance to prtK and to V8 but only weak resistance to trypsin at the T2 site. Because prtK and V8 primarily attack the loops connecting the A domain to the transmembrane helices whereas the trypsin T2 site (Arg(198)) is located on the outermost loop in the A domain, these results lead us to propose that the A domain undergoes a large amount of rotation between E(1)P and E(2)P. Combined with previous results, we demonstrated that four states can be clearly distinguished by the susceptibility to three proteases, which will be very useful for establishing the conditions for structural studies.     

Association of methylenetetrahydrofolate (MTHFR) and apolipoprotein E (apo E) genotypes with homocysteine, vitamin and lipid levels in carotid stenosis

The aim of the study was to investigate the association between methylenetetrahydrofolate (MTHFR) genotypes and levels of homocysteine (Hcy), folate, vitamin B12 and lipids as well as the association between apolipoprotein E (apo E) genotypes and levels of lipids in a Croatian healthy control group and a group of patients with > 70% carotid stenosis (CS). The study included 98 Croats, 38 patients with > 70% carotid stenosis and 60 age- and sex-matched controls. The MTHFR and apo E genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), Hcy by enzyme immunoassay, vitamins by immunochemiluminiscence, and lipids by spectrophotometric method. There was no difference between control subjects and CS patients in the distribution of C677T MTHFR genotypes (p=0. 786) and alleles (p=0.904), however, differences in the frequencies of apo E genotypes (p=0.012) and alleles (p=0.029) were statistically significant. The odds ratio for apo E 3/4 genotype was 3.93 (95% CI 1.23-12.61). Hyperhomocysteinemia (> or =15 micromol/L) was found in 11% of CS patients and 5% of control subjects. Total cholesterol, triglycerides, vitamin B12 and folate were statistically different in "all MTHFR genotypes" (p<0.001, p<0.01, p=0.044 and p=0.036, respectively), and in TC/TT (p<0.001, p=0.003, p=0.030 and p=0.032, respectively) groups. The levels of total cholesterol, LDL cholesterol and triglycerides in the apo E 3/3, and total cholesterol in the apo E 3/4 group yielded statistical difference. An association was found of apo E 3/4 genotype but not of MTHFR genotypes with the risk of CS. MTHFR and apo E affect blood lipid levels, which was statistically confirmed. An association was also recorded between hyperhomocysteinemia and patients with CS. Vitamin status in CS showed a statistically verified association with TC/TT MTHFR genotype. In the group of patients with TC/TT MTHFR genotype, lower vitamin B12 and higher folate values were recorded. The results of multiple logistic analysis showed that there was no statistical significance of Hcy levels (OR 2.403, p=0.334) or conventional vascular risk factors such as smoking habit (OR 0.505, p=0.149), age (OR 1.048, p=0.087) or sex (OR 2.037, p=0.112) in predicting CS.     

Insulin and PIP3 activate PKC-zeta by mechanisms that are both dependent and independent of phosphorylation of activation loop (T410) and autophosphorylation (T560) sites

Activation of protein kinase C-zeta (PKC-zeta) by insulin requires phosphatidylinositol (PI) 3-kinase-dependent increases in phosphatidylinositol-3,4,5-(PO(4))(3) (PIP(3)) and phosphorylation of activation loop and autophosphorylation sites, but actual mechanisms are uncertain. Presently, we examined: (a) acute effects of insulin on threonine (T)-410 loop phosphorylation and (b) effects of (i) alanine (A) and glutamate (E) mutations at T410 loop and T560 autophosphorylation sites and (ii) N-terminal truncation on insulin-induced activation of PKC-zeta. Insulin acutely increased T410 loop phosphorylation, suggesting enhanced action of 3-phosphoinositide-dependent protein kinase-1 (PDK-1). Despite increasing in vitro autophosphorylation of wild-type PKC-zeta and T410E-PKC-zeta, insulin and PIP(3) did not stimulate autophosphorylation of T560A, T560E, T410A/T560E, T410E/T560A, or T410E/T560E mutant forms of PKC-zeta; thus, T560 appeared to be the sole autophosphorylation site. Activating effects of insulin and/or PIP(3) on enzyme activity were completely abolished in T410A-PKC-zeta, partially compromised in T560A-PKC-zeta, T410E/T560A-PKC-zeta, and T410A/T560E-PKC-zeta, and largely intact in T410E-PKC-zeta, T560E-PKC-zeta, and T410E/T560E-PKC-zeta. Activation of the T410E/T560E mutant suggested a phosphorylation-independent mechanism. As functional correlates, insulin effects on epitope-tagged GLUT4 translocation were compromised by expression of T410A-PKC-zeta, T560A-PKC-zeta, T410E/T560A, and T410A/T560E-PKC-zeta but not T410E-PKC-zeta, T560E-PKC-zeta, or T410E/T560E-PKC-zeta. Insulin, but not PIP(3), activated truncated, pseudosubstrate-lacking forms of PKC-zeta and PKC-lambda by a wortmannin-sensitive mechanism, apparently involving PI 3-kinase/PDK-1-dependent phosphorylations but independent of PIP(3)-dependent conformational activation. Our findings suggest that insulin, via PIP(3), provokes increases in PKC-zeta enzyme activity through (a) PDK-1-dependent T410 loop phosphorylation, (b) T560 autophosphorylation, and (c) phosphorylation-independent/conformational-dependent relief of pseudosubstrate autoinhibition.     

Mutation probe of gene structure in E. coli: suppressor mutations in the seven-tRNA operon

Summary Cells defective in uracil-DNA glycosylase (ung:: Tn10) were used in two ways to reveal differences in select point mutations (GC to AT transitions) within the seven-tRNA operon of E. coli. The mutations were indicated as de novo or converted glutamine tRNA suppressor mutations in the genes glnU and/or glnV: (1) the kinetics of photoenzymatic monomerization of pyrimidine dimers quantitated by ung-dependent UV mutagenesis indicated more rapid repair of dimers at sites for converted suppressor mutation than of dimers at sites for de novo suppressor mutation, and (2) spontaneous deamination of cytosine was considerably more frequent at sites for converted suppressor mutation than at sites for de novo suppressor mutation. To explain these results we suggest the physical structure of the DNA in vivo is different at different sites in the seven-tRNA operon. The non-transcribed strand including specifically the anticodon region of the site for converted suppressor mutation may frequently be looped out in a single strand so that a T=C dimer is more accessible to DNA photolyase or a free cytosine residue of non-irradiated DNA is in an aqueous environment conducive to deamination. In addition, we analysed the spontaneous de novo suppressor mutation data to determine an estimate for the in vivo rate of cytosine deamination in double strand DNA of 3.2×10¹³/sec.     

Functional and phenotypic evidence for presentation of E alpha 52-68 structurally related self-peptide(s) in I-E alpha-deficient mice

The Y-Ae mAb and the 1H3.1 TCR-alpha beta (V alpha 1/V beta 6) are two immune receptors specific for I-Ab MHC class II molecules complexed to the 52-68 fragment of the alpha-chain of I-E class II molecules (the E alpha 52-68 peptide). A profound intrathymic negative selection occurs in 1H3.1 TCR transgenic mice in the presence of an I-E alpha transgene. The administration of mAbs to 1H3.1/I-E alpha double-transgenic newborn mice reveals that Y-Ae, but not the isotype-matched anti-I-E Y17 mAb, rescues a significant number of mature (V beta 6highCD4+CD8-) thymocytes and allows the detection of E alpha 52-68-reactive T cells in the periphery. These observations indicate that deletion of autoreactive T cells can be specifically inhibited in vivo by an mAb specific for the deleting self-peptide:self-MHC class II complex. Similar inhibition experiments indicate that C57BL/6 (I-Ab+/I-E alpha-) mice constitutively express an E alpha-independent, Y-Ae-recognizable epitope(s). This finding is confirmed by the phenotypic analysis of mature (MHC class II high) C57BL/6 bone marrow-derived dendritic cells. Collectively, these observations further illustrate the peptide specificity of negative selection and demonstrate that MHC class II-positive cells from unmanipulated C57BL/6 mice that lack a functional I-E alpha gene can assemble one or more self-peptide:I-Ab complexes recognizable by the E alpha 52-68:I-Ab complex-specific Y-Ae mAb.     

(4E)-dehydrocitrals [(2E,4E)- and (2Z,4E )-3,7-dimethyl-2,4,6-octatrienals] from acarid mite Histiogaster sp. A096 (Acari: Acaridae)

A mixture of two monoterpenes was obtained as the opisthonotal gland secretion from unidentified Histiogaster sp. A096 (Acari: Acaridae), and their structures were elucidated to be (4E)-dehydrocitrals [(2E,4E)- and (2Z,4E)-3,7-dimethyl-2,4,6-octatrienals] by GC/MS, GC/FT-IR, UV and 1H-NMR spectra. Both isomers of (4E)-dehydrocitral prepared by syntheses in 4 steps from 3-methyl-2-butenal with 34.2% yields (based on the ylide) were separated by column chromatography into the (2E,4E)- and (2Z,4E)-3,7-dimethyl-2,4,6-octatrienal. Mass spectra together with GC retention times of the purified natural (4E)-dehydrocitrals were identical with those of synthetic (2E,4E)-3,7-dimethyl-2,4,6-octatrienal and (2Z,4E)-3,7-dimethyl-2,4,6-octatrienal. The geometry at the 2-C position of both synthetic (4E)-dehydrocitrals was confirmed by NOESY analyses. This is the first identification of (4E)-dehydrocitrals from the animal kingdom.     

Regeneration of the antiviral drug (E)-5-(2-bromovinyl)-2''-deoxyuridine in vivo

The highly potent and selective antiherpes drug BVdUrd [(E)-5-(2-bromovinyl)-2'-deoxyuridine] is cleared within 2-3 hours from the bloodstream upon intraperitoneal administration to rats. It is degraded to BVUra [(E)-5-(2-bromovinyl)uracil] and this inactive metabolite is cleared very slowly from the bloodstream so that 24 hours after the administration of BVdUrd, BVUra is still detectable in the plasma. This contrasts with several other 5-substituted uracils, i.e. 5-fluorouracil, 5-iodouracil, 5-trifluorothymine and thymine itself, which are, like their 2'-deoxyuridine counterparts FdUrd, IdUrd, F3dThd and dThd, cleared from the plasma within 2-3 hours. The injection of dThd or any of the other 5-substituted 2'-deoxyuridines at 3 hours after the injection of BVdUrd, that is at a time when BVdUrd has disappeared completely from the circulation, results in the re-apparition of BVdUrd in the plasma. Apparently, BVdUrd is regenerated from BVUra following the reaction catalyzed by pyrimidine nucleoside phosphorylases : BVUra + dThd----BVdUrd + Thy. BVdUrd can even be generated de novo if dThd (or FdUrd, IdUrd or F3dThd) are administered 3 hours after a preceding injection of BVUra. These findings represent a unique example of the (re)generation of an active drug from its inactive metabolite in vivo.     

Interactions between the predators thanasimus formicarius (Col.: Cleridae) and rhizophagus depressus (Col: Rhizophagidae), and the bark beetle tomicus Piniperda (Col.: Scolytidae)

The occurrences of Thanasimus formicarius (L.) (Cleridae), Rhizophagus depressus (F.) (Rhizophagidae), and Epuraea marseuli Reitter (Nitidulidae) in cut Scots pines, Pinus sylvestris L., attacked by Tomicus piniperda (L.) (Col.: Scolytidae) were recorded in the field, and interactions between the species were studied in caged pine bolts attacked by T. piniperda. T. formicarius eggs and R. depressus adults were abundant in the T. piniperda attacked trees, whereas only a few individuals of E. marseuli were found. T. formicarius and R. depressus, but not E. marseuli, reproduced in the caged bolts. T. piniperda offspring production per unit area of bark was reduced by 41% when reared with R. depressus, by 81% when reared with T. formicarius, and by 89% when all three species were reared together, compared with T. piniperda alone. The interaction between T. formicarius and R. depressus was mutually antagonistic. When both species were present in the same bolt the total number of larvae was reduced by 49% for R. depressus and the number of large larvae (length > 10 mm) was reduced by 35% for T. formicarius compared with their respective production values when each species was present alone with the bark beetle. There was a positive relationship between T. piniperda egg gallery density and the production of R. depressus larvae per m². Larvae of both R. depressus and T. formicarius developed into new adults during the first summer.

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Résumé Interactions entre les prédateursThanasimus formicarius (Col.: Cleridae) etRhizophagus depressus (Col.: Rhizophagidae) et le scolyteTomicus piniperda (Col.: Scolytidae) La présence deThanasimus formicarius (L.) (Cleridae),Rhizophagus depressus (F.) (Rhizophagidae), etEpuraea marseuli Reitter (Nitidulidae) a été étudiée sur le terrain dans des pins sylvestres (Pinus sylvestiris L) abattus, attaqués partomicus piniperda (L.) (Col.: Scolytidae) et les relations entre les espèces ont été étudiées sur des rondins de pin attaqués parT. piniperda et placés sous cage. Le nombre d’∄ufs deT. formicarius et d’adultes deR. depressus était important dans les arbres attaqués parT. piniperda, alors que seuls quelques individus deE. marseuli ont pu être trouvés.T. formicarius etR. depressus, mais pasE. marseuli, se sont reproduits dans les rondins sous cage. La production de descendants deT. piniperda par unité de surface d’écorce était réduite de 41% quand le scolyte était élevé avecR. depressus, de 81% en élevage avecT. formicarius et de 89% quand les trois espèces sont élevées ensemble, par comparaison avecT. piniperda seul. Les interactions entreT. formicarius etR. depressus étaient mutuellement antagonistes. Quand les deux espèces étaient présentes dans le même rondin, le nombre total de larves était réduit de 49% pourR. depressus et le nombre de grosses larves (longueur > 10 mm) était réduit de 35% pourT. formicarius comparé aux valeurs respectives quand chaque espèce était présente isolément avec le scolyte. Il y a une corrélation positive entre la densité de galeries avec des ∄ufs deT. piniperda et la production de larves deR. depressus par m². Les larves deR. depressus et deT. formicarius se sont transformés en adultes l’été suivant.

     

Étude de la consommation alimentaire d'Exochomus flaviventris (Col.: Coccinellidae) prédateur de la cochenille du maniocPhenacoccus manihoti (Hom.: Pseudococcidae)

Résumé Les besoins alimentaires de chaque stade de développement larvaire et des jeunes femelles d'E. flaviventris Mader ont été définis par rapport à deux cochenilles associées au manioc;:Planococcus citri Risso (proie locale) etPhenacoccus manihoti Mat.-Ferrero (proie exotique) dans les conditions de laboratoire (T=25°C±1°C; H.R.=80–90%; photopériode=L/D: 12/12). Ces deux proies constituent des ?nourritures essentielles? pourE. flaviventris qui les consomme en plus grande quantité par rapport aux autres coccinelles qui se nourrissent aux dépens, de la cochenille du manioc. Il faut en moyenne 71,8 mg de matière fra?che deP. manihoti (œufs+jeunes femelles) ou 86,9 mg deP. citri (œufs+jeunes femelles) àE. flaviventris pour atteindre le stade adulte. Dans chaque cas, les larves du prédateur de quatrième stade se montrent plus voraces avec plus de 70% de la consommation totale. Les jeunes, femelles consomment moins que les larves du dernier stade principalement quand il s'agit de la proie exotique. P. manihoti semble avoir été rapidement adoptée parE. flaviventris après son introduction accidentelle en Afrique. Sans être d'une valueur alimentaire exceptionnelle, elle est mieux exploitée que la cochenille indigène et procure un poids moyen de 10,9 mg aux adultes du prédateur à leur émergence.

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Summary Food requirements of each larval stage and of young females ofExochomus flaviventris have been defined regarding the two coccids associated to cassava:Phenacoccus citri (indigenous prey) andPhenacoccus manihoti (exotic prey) under laboratory conditions (25±1°C, 80–90% RH and L/D: 12/12). These 2 preys constitute the main food forE. flaviventris as this ladybird feeds on it much more than all the other coccinellids preying also on the cassava mealybug.E. flaviventris needs an average of 71.8 mg of freshP. manihoti (eggs and young, females) or 86.9 mg ofP. citri (eggs and young voracious with 70% of the total consumption. Young females feed less than the last instar larvae, especially when the exotic prey is involved. P. manihoti seems to have been rapidly choosen byE. flaviventris after its accidental introduction into Africa. Even if it is not an excellent prey from the food angle, it is better exploited thant the indigenous mealybug and adults of an average weight of 10.9 mg are obtained after emergence.

     

Phosphorylation dynamics of eukaryotic initiation factor 4E binding protein 1 (4E-BP1) is discordant with its potential to interact with eukaryotic initiation factor 4E (eIF4E)

Mammalian target of rapamycin (mTOR) controls cellular growth and proliferation by virtue of its ability to regulate protein translation. Eukaryotic initiation factor 4E (eIF4E) binding protein 1 (4E-BP1) — a key mTOR substrate, binds and sequesters eIF4E to impede translation initiation that is supposedly overcome upon 4E-BP1 phosphorylation by mTOR. Ambiguity surrounding the precise identity of mTOR regulated sites in 4E-BP1 and their invariable resistance to mTOR inactivation raises concerns about phospho-regulated model proposed for 4E:4E-BP1 interaction. Our attempt to mimic dephosphorylation associated with rapamycin response by introducing phospho deficient mutants for sites implicated in regulating 4E:4E-BP1 interaction individually or globally highlighted no obvious difference in the quantum of their association with CAP bound 4E when compared with their phosphomimicked counterparts or the wild type 4E-BP1. TOS or RAIP motif deletion variants compromised for raptor binding and resultant phosphodeficiency did little to influence their association with CAP bound 4E. Interestingly ectopic expression of ribosomal protein S6 kinase 1 (S6K1) that restored 4E-BP1 sensitivity to rapamycin/Torin reflected by instant loss of 4E-BP1 phosphorylation, failed to bring about any obvious change in 4E:4E-BP1 stoichiometry. Our data clearly demonstrate a potential disconnect between rapamycin response of 4E-BP1 and its association with CAP bound 4E.     

Protective effects of vitamin E and curcumin on L-thyroxine-induced rat testicular oxidative stress

Present study examines effects of curcumin and vitamin E on oxidative stress parameters, antioxidant defence enzymes and oxidized (GSSG) and reduced glutathione (GSH) levels in testis of L-thyroxine (T4)-induced hyperthyroid rats. The oxidative stress in T4-treated rat testis was evident from elevation in oxidative stress parameters such as lipid peroxide and protein carbonyl contents, decrease in superoxide dismutase (SOD) and catalase (CAT) activities and increase in glutathione peroxidase (GPx) activity. This is accompanied with decrease in number and mortality of epididymal sperms. When the T4-treated rats were fed with vitamin E and/or curcumin, the lipid peroxide and protein carbonyl contents in crude homogenates of testes decreased to normal level. Treatment of curcumin and/or vitamin E to T4-treated rats resulted in elevation of SOD level in postmitochondrial fraction (PMF) and mitochondrial fraction (MF) and CAT in PMF, with decreased GPx activity in MF. However, curcumin or vitamin E was unable to change GPx activity alone but in together they elevated the GPx in PMF of T4-treated rat testis. Both the antioxidants are incapable of producing significant changes in GSH:GSSG ratio of PMF of T4-treated rats. In MF, GSH:GSSG ratio elevated and decreased respectively by curcumin and vitamin E treatments to T4-treated rats, however, in together these antioxidants caused an elevated GSH:GSSG ratio with a value less than when vitamin E given alone to T4-treated rats. Vitamin E not the curcumin elevates total sperm count and percentage of live sperm impaired by hyperthyroid state. In summary, both vitamin E and curcumin are efficient in protecting testis from oxidative stress generated by T4 mainly in restoring antioxidant enzymes to the level of euthyroid animals up to some extent but vitamin E is more efficient than curcumin.     

Diversity and genetic structure of the Mexican endemic epiphyte Tillandsia achyrostachys E. Morr. ex Baker var. achyrostachys (Bromeliaceae)

BACKGROUND AND AIMS: The monoecious, bird-pollinated epiphytic Tillandsia achyrostachys E. Morr. ex Baker var. achyrostachys is an endemic bromeliad of the tropical dry forests of Mexico with clonal growth. In the Sierra de Huautla Natural Reserve this species shows a host preference for Bursera copallifera (Sessé & Moc ex. DC) Bullock. As a result of deforestation in the study area, B. copallifera has become a rare tree species in the remaining forest patches. This human-induced disturbance has directly affected the population densities of T. achyrostachys. In this study the genetic consequences of habitat fragmentation were assessed by comparing the genetic diversity, gene flow and genetic differentiation in six populations of T. achyrostachys in the Sierra de Huautla Natural Reserve, Mexico. METHODS: Allozyme electrophoresis of sixteen loci (eleven polymorphic and five monomorphic) were used. The data were analysed with standard statistical approximations for obtaining diversity, genetic structure and gene flow. KEY RESULTS: Genetic diversity and allelic richness were: HE = 0.21 +/- 0.02, A = 1.86 +/- 0.08, respectively. F-statistics revealed a deficiency of heterozygous plants in all populations (Fit = 0.65 +/- 0.02 and Fis = 0.43 +/- 0.06). Significant genetic differentiation between populations was detected (Fst = 0.39 +/- 0.07). Average gene flow between pairs of populations was relatively low and had high variation (Nm = 0.46 +/- 0.21), which denotes a pattern of isolation by distance. The genetic structure of populations of T. achyrostachys suggests that habitat fragmentation has reduced allelic richness and genetic diversity, and increased significant genetic differentiation (by approx. 40 %) between populations. CONCLUSIONS: The F-statistic values (>0) and the level of gene flow found suggest that habitat fragmentation has broken up the former population structure. In this context, it is proposed that the host trees of T. achyrostachys should be considered as a conservation priority, since they represent the limiting factor to bromeliad population growth and connectivity.     

The low molecular weight (LMW) isoforms of cyclin E deregulate the cell cycle of mammary epithelial cells

Cyclin E in complex with CDK2 is a positive regulator of the G1 to S phase transition of the cell cycle and is responsible for cells passing the restriction point, committing the cell to another round of cell division. Cyclin E is overexpressed and proteolytically cleaved into low molecular weight (LMW) isoforms in breast cancer cell lines and tumor tissues compared to normal cells and tissues. These alterations in cyclin E are linked to poor prognosis in breast cancer patients. In order to evaluate the biological effects of the LMW cyclin E, immortalized mammary epithelial cells, 76NE6, were stably transfected with each of the three cyclin E constructs. Our results reveal that the LMW forms of cyclin E (T1 and T2) are biologically functional, as their overexpression in the immortalized cells increases the ability of these cells to enter S and G2/M phase by 2 fold over full length or vector-alone transfected cells, concomitant with an increased rate of cell proliferation. In addition, these LMW isoforms are biochemically hyperactive, shown by their ability to phosphorylate substrates such as histone H1 4 fold more in cells transfected with T1 or T2 versus cells transfected with the full length form. These results suggest that overexpression of the LMW forms of cyclin E is mitogenic, stimulating the cells to progress through the cell cycle much more efficiently than the full length cyclin E.