Differential regulation of Knotted1-like genes during establishment of the shoot apical meristem in Norway spruce (Picea abies)

Establishment of the shoot apical meristem (SAM) in Arabidopsis embryos requires the KNOXI transcription factor SHOOT MERISTEMLESS. In Norway spruce (Picea abies), four KNOXI family members (HBK1, HBK2, HBK3 and HBK4) have been identified, but a corresponding role in SAM development has not been demonstrated. As a first step to differentiate between the functions of the four Norway spruce HBK genes, we have here analyzed their expression profiles during the process of somatic embryo development. This was made both under normal embryo development and under conditions of reduced SAM formation by treatment with the polar auxin transport inhibitor NPA. Concomitantly with the formation of an embryonic SAM, the HBK2 and HBK4 genes displayed a significant up-regulation that was delayed by NPA treatment. In contrast, HBK1 and HBK3 were up-regulated prior to SAM formation, and their temporal expression was not affected by NPA. Ectopic expression of the four HBK genes in transgenic Arabidopsis plants further supported similar functions of HBK2 and HBK4, distinct from those of HBK1 and HBK3. Together, the results suggest that HBK2 and HBK4 exert similar functions related to the SAM differentiation and somatic embryo development in Norway spruce, while HBK1 and HBK3 have more general functions during embryo development

Protein supplementation in strength and conditioning adepts: knowledge, dietary behaviour and practice in Palermo, Italy

Background: It is known that supplement use is a widespread and accepted practice by athletes and people who attend commercial gyms. Little is known about protein supplement amongst people undertaking strength training in commercial gyms in Italy when compared to the US. Objective: The purpose of this study was to examine the use of protein supplementation, alone or in association with other supplements, and dietary behavior amongst regular fitness center attendees in Palermo, Italy. Design: Resistance training information have been collected from 800 regular fitness center attendees for the initial analysis. A specific questionnaire was generated for the experimentation. Data were collected using a face-to-face interview method. Supplement users were then compared to the non users and analyzed using a one-way ANOVA, Kruskall-Wallis, chi-square test or exact test of Fisher when appropriate. Results: 30.1% of the respondents use dietary supplements during their training as a believe it is the "way to gain muscles and strength". Whey protein shakes (50.0%) mixed with creatine and amino-acids (48.3%) were the most frequent choices amongst the users. A majority of the subjects (34.0%) appeared to rely on their gym instructors' advice for their intake; a lower proportion (13.0%) consulted physicians, while none of them consulted nutritionists. A high consumption of milk has been noticed in both users (67,7%) and non-users (52,8%); supplement non-users consumed significantly more snacks and bakery products than users per week (P < 0.001), while users consumed significantly more protein-rich foods (P < 0.01) with a particular preference for meat (48.0%). Conclusions: A considerable number of regular strength training adepts consume protein supplements mixed with other products (mainly creatine and amino-acids). Limited numbers consult "dietary specialists" and rely mainly on their instructors. We emphasize on the importance of the dissemination of scientifically based information about supplementation in this environment and the promotion of updated educational programs for the instructors

The influence of alkalosis on repeated high-intensity exercise performance and acid–base balance recovery in acute moderate hypoxic conditions

Purpose Exacerbated hydrogen cation (H⁺) production is suggested to be a key determinant of fatigue in acute hypoxic conditions. This study, therefore, investigated the effects of NaHCO3 ingestion on repeated 4 km TT cycling performance and post-exercise acid–base balance recovery in acute moderate hypoxic conditions. Methods Ten male trained cyclists completed four repeats of 2 × 4 km cycling time trials (TT1 and TT2) with 40 min passive recovery, each on different days. Each TT series was preceded by supplementation of one of the 0.2 g kg⁻¹ BM NaHCO3 (SBC2), 0.3 g kg⁻¹ BM NaHCO3 (SBC3), or a taste-matched placebo (0.07 g kg⁻¹ BM sodium chloride; PLA), administered in a randomized order. Supplements were administered at a pre-determined individual time to peak capillary blood bicarbonate concentration ([HCO3⁻]). Each TT series was also completed in a normobaric hypoxic chamber set at 14.5% FiO2 (~ 3000 m). Results Performance was improved following SBC3 in both TT1 (400.2 ± 24.1 vs. 405.9 ± 26.0 s; p = 0.03) and TT2 (407.2 ± 29.2 vs. 413.2 ± 30.8 s; p = 0.01) compared to PLA, displaying a very likely benefit in each bout. Compared to SBC2, a likely and possible benefit was also observed following SBC3 in TT1 (402.3 ± 26.5 s; p = 0.15) and TT2 (410.3 ± 30.8 s; p = 0.44), respectively. One participant displayed an ergolytic effect following SBC3, likely because of severe gastrointestinal discomfort, as SBC2 still provided ergogenic effects. Conclusion NaHCO3 ingestion improves repeated exercise performance in acute hypoxic conditions, although the optimal dose is likely to be 0.3 g kg⁻¹ BM

EST Analysis of Ostreococcus lucimarinus, the Most Compact Eukaryotic Genome, Shows an Excess of Introns in Highly Expressed Genes

Background: The genome of the pico-eukaryotic (bacterial-sized) prasinophyte green alga Ostreococcus lucimarinus has one of the highest gene densities known in eukaryotes, yet it contains many introns. Phylogenetic studies suggest this unusually compact genome (13.2 Mb) is an evolutionarily derived state among prasinophytes. The presence of introns in the highly reduced O. lucimarinus genome appears to be in opposition to simple explanations of genome evolution based on unidirectional tendencies, either neutral or selective. Therefore, patterns of intron retention in this species can potentially provide insights into the forces governing intron evolution. Methodology/Principal Findings: Here we studied intron features and levels of expression in O. lucimarinus using expressed sequence tags (ESTs) to annotate the current genome assembly. ESTs were assembled into unigene clusters that were mapped back to the O. lucimarinus Build 2.0 assembly using BLAST and the level of gene expression was inferred from the number of ESTs in each cluster. We find a positive correlation between expression levels and both intron number (R = +0.0893, p =,0.0005) and intron density (number of introns/kb of CDS; R = +0.0753, p =,0.005). Conclusions/Significance: In a species with a genome that has been recently subjected to a great reduction of non-coding DNA, these results imply the existence of selective/functional roles for introns that are principally detectable in highly expressed genes. In these cases, introns are likely maintained by balancing the selective forces favoring their maintenanc

DNA damage by lipid peroxidation products: implications in cancer, inflammation and autoimmunity

Oxidative stress and lipid peroxidation (LPO) induced by inflammation, excess metal storage and excess caloric intake cause generalized DNA damage, producing genotoxic and mutagenic effects. The consequent deregulation of cell homeostasis is implicated in the pathogenesis of a number of malignancies and degenerative diseases. Reactive aldehydes produced by LPO, such as malondialdehyde, acrolein, crotonaldehyde and 4-hydroxy-2-nonenal, react with DNA bases, generating promutagenic exocyclic DNA adducts, which likely contribute to the mutagenic and carcinogenic effects associated with oxidative stress-induced LPO. However, reactive aldehydes, when added to tumor cells, can exert an anticancerous effect. They act, analogously to other chemotherapeutic drugs, by forming DNA adducts and, in this way, they drive the tumor cells toward apoptosis. The aldehyde-DNA adducts, which can be observed during inflammation, play an important role by inducing epigenetic changes which, in turn, can modulate the inflammatory process. The pathogenic role of the adducts formed by the products of LPO with biological macromolecules in the breaking of immunological tolerance to self antigens and in the development of autoimmunity has been supported by a wealth of evidence. The instrumental role of the adducts of reactive LPO products with self protein antigens in the sensitization of autoreactive cells to the respective unmodified proteins and in the intermolecular spreading of the autoimmune responses to aldehyde-modified and native DNA is well documented. In contrast, further investigation is required in order to establish whether the formation of adducts of LPO products with DNA might incite substantial immune responsivity and might be instrumental for the spreading of the immunological responses from aldehyde-modified DNA to native DNA and similarly modified, unmodified and/or structurally analogous self protein antigens, thus leading to autoimmunity