Interaction between cadmium, zinc and silver-substituted plastocyanin and cytochrome b 6 f complex — heavy metals toxicity towards photosynthetic apparatus

This paper reports the results of research on the interaction between the cytochrome f of the active cytochrome b ₆ f complex (incubated with Cd-, Zn-, and Ag-substituted plastocyanins) and Cu-plastocyanin. The presented studies show, that the metal derivatives of plastocyanin can have an influence on the photosynthetic electron transfer path: cytochrome b ₆ f complex — photosystem I. The metal-substituted plastocyanins occupy the plastocyanin electron transfer site of the cytochrome f. The stopped-flow measurements show, that although the metal derivatives of plastocyanin do not influence the rate of cyt f- Pc electron transfer, creation of the non-electron-transfer complexes characterised by a strong binding between the cyt f and substituted plastocyanins and their slow release, dependent on the redox state of the substituted metal, results in the decrease of a turnover of the cytochrome complex. The research was done in the Department of Plant Biochemistry, Freiburg University, Sch?nzlestrasse 1, 79 104 Freiburg, Germany     

Why pigs are important in Papua? Wealth,height and reproductive success among the Yali tribe of West Papua

Many studies have investigated how different variables influence the reproductive success (RS) in the populations of natural birth control. Here, we tested hypotheses about positive relationship between wealth, height and several measures of RS in an indigenous, traditional society from West Papua. The study was conducted among the Yali tribe in a few small, isolated mountain villages. In this tribe, a man's wealth is measured by the number of pigs he possesses. We found that wealth was related to fertility and number of living children, but not to child mortality in both men and women. Additionally, child mortality increased with the number of children in a family. Finally, we did not observe any relationship between height and reproductive success measures or wealth. We provide several possible explanations of our results and also put forward hypothetical background for further studies of indigenous populations.     

The FTO A/T Polymorphism and Elite Athletic Performance: A Study Involving Three Groups of European Athletes

Objective

The FTO A/T polymorphism (rs9939609) is a strong candidate to influence obesity-related traits. Elite athletes from many different sporting disciplines are characterized by low body fat. Therefore, the aim of this study was to assess whether athletic status is associated with the FTO A/T polymorphism.

Subjects and Methods

A large cohort of European Caucasians from Poland, Russia and Spain were tested to examine the association between FTO A/T polymorphism (rs9939609) and athletic status. A total of 551 athletes were divided by type of sport (endurance athletes, n = 266 vs. sprint/power athletes, n = 285) as well as by level of competition (elite-level vs. national-level). The control group consisted of 1,416 ethnically-matched, non-athletic participants, all Europeans. Multinomial logistic regression analyses were conducted to assess the association between FTO A/T genotypes and athletic status/competition level.

Results

There were no significantly greater/lesser odds of harbouring any type of genotype when comparing across athletic status (endurance athletes, sprint/power athletes or control participants). These effects were observed after controlling for sex and nationality. Furthermore, no significantly greater/lesser odds ratios were observed for any of the genotypes in respect to the level of competition (elite-level vs. national-level).

Conclusion

The FTO A/T polymorphism is not associated with elite athletic status in the largest group of elite athletes studied to date. Large collaborations and data sharing between researchers, as presented here, are strongly recommended to enhance the research in the field of exercise genomics.     

Structure and Ultrastructure of the Endodermal Region of the Alimentary Tract in the Freshwater Shrimp Neocaridina heteropoda (Crustacea,Malacostraca)

The freshwater shrimp Neocaridina heteropoda (Crustacea, Malacostraca, Decapoda) originates from Asia and is one of the species that is widely available all over the world because it is the most popular shrimp that is bred in aquaria. The structure and the ultrastructure of the midgut have been described using X-ray microtomography, transmission electron microscopy, light and fluorescence microscopes. The endodermal region of the alimentary system in N. heteropoda consists of an intestine and a hepatopancreas. No differences were observed in the structure and ultrastructure of males and females of the shrimp that were examined. The intestine is a tube-shaped organ and the hepatopancreas is composed of two large diverticles that are divided into the blind-end tubules. Hepatopancreatic tubules have three distinct zones – proximal, medial and distal. Among the epithelial cells of the intestine, two types of cells were distinguished – D and E-cells, while three types of cells were observed in the epithelium of the hepatopancreas – F, B and E-cells. Our studies showed that the regionalization in the activity of cells occurs along the length of the hepatopancreatic tubules. The role and ultrastructure of all types of epithelial cells are discussed, with the special emphasis on the function of the E-cells, which are the midgut regenerative cells. Additionally, we present the first report on the existence of an intercellular junction that is connected with the E-cells of Crustacea.     

Chemically-induced affinity star restriction specificity: a novel TspGWI/sinefungin endonuclease with theoretical 3-bp cleavage frequency

The type IIS/IIC restriction endonuclease TspGWI recognizes the sequence 5'-ACGGA-3', cleaving DNA 11/9 nucleotides downstream. Here we show that sinefungin, a cofactor analog of S-adenosyl methionine, induces a unique type of relaxation in DNA recognition specificity. In the presence of sinefungin, TspGWI recognizes and cleaves at least 12 degenerate variants of the original recognition sequence that vary by single base pair changes from the original 5-bp restriction site with only a single degeneracy per variant appearing to be allowed. In addition, sinefungin was found to have a stimulatory effect on cleavage at these nondegenerate TspGWI recognition sites, irrespective of their number or the DNA topology. Interestingly, no fixed "core" could be identified among the new recognition sequences. Theoretically, TspGWI cleaves DNA every 1024 bp, while sinefungin-induced activity cleaves every 78.8 bp, corresponding to a putative 3-bp long recognition site. Thus, the combination of sinefungin and TspGWI represents a novel frequent cutter, next only to CviJI/CviJI*, that should prove useful in DNA cloning methodologies.     

Ubiquitin hydrolase Uch-L1 rescues beta-amyloid-induced decreases in synaptic function and contextual memory

The neuronal ubiquitin/proteasomal pathway has been implicated in the pathogenesis of Alzheimer's disease (AD). We now show that a component of the pathway, ubiquitin C-terminal hydrolase L1 (Uch-L1), is required for normal synaptic and cognitive function. Transduction of Uch-L1 protein fused to the transduction domain of HIV-transactivator protein (TAT) restores normal enzymatic activity and synaptic function both in hippocampal slices treated with oligomeric Abeta and in the APP/PS1 mouse model of AD. Moreover, intraperitoneal injections with the fusion protein improve the retention of contextual learning in APP/PS1 mice over time. The beneficial effect of the Uch-L1 fusion protein is associated with restoration of normal levels of the PKA-regulatory subunit IIalpha, PKA activity, and CREB phosphorylation.     

Renal nerves and nNOS: roles in natriuresis of acute isovolumetric sodium loading in conscious rats

It was hypothesized that renal sympathetic nerve activity (RSNA) and neuronal nitric oxide synthase (nNOS) are involved in the acute inhibition of renin secretion and the natriuresis following slow NaCl loading (NaLoad) and that RSNA participates in the regulation of arterial blood pressure (MABP). This was tested by NaLoad after chronic renal denervation with and without inhibition of nNOS by S-methyl-thiocitrulline (SMTC). In addition, the acute effects of renal denervation on MABP and sodium balance were assessed. Rats were investigated in the conscious, catheterized state, in metabolic cages, and acutely during anesthesia. NaLoad was performed over 2 h by intravenous infusion of hypertonic solution (50 micromol.min(-1).kg body mass(-1)) at constant body volume conditions. SMTC was coinfused in amounts (20 microg.min(-1).kg(-1)) reported to selectively inhibit nNOS. Directly measured MABPs of acutely and chronically denervated rats were less than control (15% and 9%, respectively, P < 0.005). Plasma renin concentration (PRC) was reduced by renal denervation (14.5 +/- 0.2 vs. 19.3 +/- 1.3 mIU/l, P < 0.005) and by nNOS inhibition (12.4 +/- 2.3 vs. 19.6 +/- 1.6 mlU/l, P < 0.005). NaLoad reduced PRC (P < 0.05) and elevated MABP modestly (P < 0.05) and increased sodium excretion six-fold, irrespective of renal denervation and SMTC. The metabolic data demonstrated that renal denervation lowered sodium balance during the first days after denervation (P < 0.001). These data show that renal denervation decreases MABP and renin secretion. However, neither renal denervation nor nNOS inhibition affects either the renin down-regulation or the natriuretic response to acute sodium loading. Acute sodium-driven renin regulation seems independent of RSNA and nNOS under the present conditions.