Molecular Mechanisms of Translation Initiation in Mammals Studied by in vitroReconstruction of Initiation Complexes

Papers on the mechanisms of translation initiation in mammals studied by reconstruction of initiation complexes from individual components are reviewed. The author points to the constraints of this approach and to the pitfalls ignoring which one might come to erroneous conclusions and even artifacts. In addition, some methods employed in the field as well as some technical problems are discussed in the paper, together with the means of obviating them. The review could be a guidebook for newcomers into this quite labor-consuming field.     

M(en)TORship lessons on life and death by the integrated stress response

Cells employ pro-survival and pro-adaptive pathways to cope with different forms of environmental stress. When stress is excessive, and the damage caused by it is unsustainable, cells engage pro-death pathways, which are in place to protect the host from the deleterious effects of harmed cells. Two important pathways that determine the balance between survival and death of stressed cells are the integrated stress response (ISR) and the mammalian target of rapamycin (mTOR), both of which converge at the level of mRNA translation. The two pathways have established avenues of communication to control their activity and determine the fate of stressed cells in a context-dependent manner. The functional interplay between the ISR and mTOR may have significant ramifications in the development and treatment of human diseases such as diabetes, neurodegeneration and cancer.     

1H, 13C and 15N resonance assignment of phage T4 endoribonuclease RegB

RegB is involved in the control of the phage T4 life cycle. It inactivates the phage early mRNAs when their translation is no more required. We determined its structure and identified residues involved in substrate binding. For this, all backbone and 90% of side-chain resonance frequencies were assigned.     

The control of flower initiation by gibberellin in Helianthus annuus L. (sunflower), a non-photoperiodic plant

The involvement of gibberellins in the control of flowering of sunflower was studied by direct application of GA₃ to the apex of the plants, analysis of the endogenous levels of gibberellin-like substances at different plant ages, and indirectly by the application of paclobutrazol, an inhibitor of gibberellin synthesis. GA₃ speeded-up flower initiation and floral apex development. The time of GA₃ application was more critical than the amount of GA₃ applied. The endogenous levels of gibberellin-like compounds increased significantly by day 15 after sowing. The application of paclobutrazol markedly delayed floral initiation and this effect was also depedent on plant age. Both GA₃ and paclobutrazol had their greatest effects between 10 and 20 days after sowing suggesting that an increase in gibberellins in that time period plays a role in floral initiation.     

Gender identification of shovelnose sturgeon using ultrasonic and endoscopic imagery and the application of the method to the pallid sturgeon

Monthly sampling of shovelnose sturgeon Scaphirhynchus platorynchus , a biological surrogate for the endangered pallid sturgeon Scaphirhynchus albus , was conducted to develop a multi‐seasonal profile of reproductive stages. Data collected included histological characteristics of gonads from wild caught fish and laboratory and field ultrasonic and endoscopic images. These data were used to compare effectiveness of ultrasonic and endoscopic techniques at identifying gender of adult shovelnose sturgeon at different reproductive stages. The least invasive method ( i.e . ultrasound) was least effective while the most invasive ( i.e . endoscope through an abdominal incision) was the most effective at identifying shovelnose sturgeon gender. In most cases, success rate for identifying males was greater than females, with success at identifying both genders greater in more advanced reproductive stages. Concomitantly, for most months average reproductive stage was more advanced for males than females. April and May were the months with the most advanced reproductive stage, and were the months when ultrasound was most effective. Methods were also applied in the Upper Missouri River to validate their use on pallid sturgeon Scaphirhynchus albus . Ultrasound was successful at identifying pallid sturgeon gender, however, endoscopic examination through the urogenital duct was only successful at identifying pallid sturgeon gender when the urogenital duct was not opaque.     

Focus: Addiction: Relapse Prevention and the Five Rules of Recovery

There are four main ideas in relapse prevention. First, relapse is a gradual process with distinct stages. The goal of treatment is to help individuals recognize the early stages, in which the chances of success are greatest. Second, recovery is a process of personal growth with developmental milestones. Each stage of recovery has its own risks of relapse. Third, the main tools of relapse prevention are cognitive therapy and mind-body relaxation, which are used to develop healthy coping skills. Fourth, most relapses can be explained in terms of a few basic rules. Educating clients in these rules can help them focus on what is important: 1) change your life (recovery involves creating a new life where it is easier to not use); 2) be completely honest; 3) ask for help; 4) practice self-care; and 5) don’t bend the rules.     

Maternal induction of larval diapause and its sensitive stage in the blow fly Lucilia sericata (Meigen) (Diptera: Calliphoridae)

Lucilia sericata has a facultative diapause in the third larval instar after cessation of feeding. Induction of the diapause is influenced by the photoperiod and temperature conditions experienced by insects in the parental generation as well as those experienced by the larvae themselves. The sensitive stage of the parental generation for induction of diapause was examined using diapause‐averting conditions of 16 h light : 8 h darkness (LD 16:8) at 25°C and diapause‐inducing conditions of LD 12:12 at 20°C. The incidence of diapause in the progeny was predominantly determined by the conditions experienced by the parents in the adult stage. Moreover, the results of reciprocal crosses showed that only the mother's experience is involved in the induction of diapause in the progeny.     

Single-molecule studies reveal branched pathways for activator-dependent assembly of RNA polymerase II pre-initiation complexes

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Plant-derived smoke solutions stimulate the growth of Lycopersicon esculentum roots in vitro

Aqueous extracts of smoke, derived from Themeda triandra, a fire-climax grass, and Passerina vulgaris, a fynbos plant, stimulated the growth of primary root sections of tomato roots in suspension culture. The optimal dilution for both extracts was 1:2000. Several of the fractions obtained from TLC separation of the Themeda and the Passerina extracts significantly promoted primary root growth. The auxins naphthaleneacetic acid (NAA), indolebutyric acid (IBA) and indoleacetic acid (IAA) were found to stimulate the growth of the primary root axis, with IAA and NAA significantly promoting lateral root number. Similarly, the naturally occurring cytokinins, zeatin and its derivatives (zeatin-O-glucoside; dihydrozeatin and zeatin riboside) stimulated primary root length. Zeatin and dihydrozeatin promoted secondary root growth, but only at very low concentrations.     

A Survey Investigating the Infection of Fusarium langsethiae and Production of HT‐2 and T‐2 Mycotoxins in UK Oat Fields

Fusarium langsethiae is a toxigenic fungal species that has been reported in European small‐grain cereal crops such as oats, wheat and barley. Although its relative contribution to fusarium head blight (FHB) symptoms is not well understood, it is reported to contaminate these cereals with high levels of HT‐2 and T‐2 trichothecenes mycotoxins that are currently under consideration for legislation by the European Commission. Ten commercial oat fields in Shropshire and Staffordshire (two adjacent counties in the Midlands) in the UK were surveyed in the 2006/2007 growing season. Samples were taken from predetermined field locations at Zadoks growth stages 32/33, 69, 77‐85 and 90‐92 for F. langsethiae biomass and HT‐2 and T‐2 toxins quantification. The results from this study showed that oats can be heavily infected with F. langsethiae and have high concentrations of HT‐2 and T‐2 toxins with no apparent FHB symptoms. The regression of HT‐2 + T‐2 toxins on F. langsethiae DNA concentration was highly significant (P < 0.001, r² = 0.55). The results indicated that although F. langsethiae had no direct effect on crop yield, it may result in indirect economic losses where the grain can be rejected or downgraded as a result of intolerable levels of HT‐2 and T‐2 toxins, which are of human food and animal feed safety concern. The influence of cultural field practices on the infection and HT‐2 and T‐2 toxins accumulation in oats was not clear and warrants further studies to identify the sources of F. langsethiae inoculum and conditions favourable for infection and mycotoxin production.