Natural and anthropogenic influences on the population structure of white‐tailed eagles in the Carpathian Basin and central Europe

European populations of the white‐tailed eagle Haliaeetus albicilla suffered a drastic decline during the 20th century. In many countries, only a few dozen breeding pairs survived or the species disappeared completely. By today, the populations have recovered, naturally or through restocking (e.g. in Scotland or the Czech Republic). In the Carpathian Basin, which is now a stronghold in southern Europe for the species in the southern part of the distribution range with more than 500 breeding pairs, only about 50 pairs survived the bottleneck. This region provides important wintering places for individuals arriving from different regions of Eurasia. In the present study, we investigated 249 DNA samples from several European countries, using 11 microsatellites and mitochondrial control region sequences (499 bp), to answer two main questions: 1) did the Carpathian Basin population recover through local population expansion or is there a significant gene flow from more distant populations as well? 2) Does the Czech population show signs in its genetic structure of the restocking with birds of unknown origin? Our microsatellite data yielded three genetically separate lineages within Europe: northern, central and southern, the latter being present exclusively in the Carpathian Basin. Sequencing of mitochondrial DNA revealed that there is one haplotype (B12) which is not only exclusive to the Carpathian Basin but it is frequent in this population. Our results suggest that in accordance with the presumably philopatric behaviour of the species, recovery of the Carpathian Basin population was mainly local, but some of the wintering birds coming from the northern and central populations contributed to its genetic composition as well. We detected considerably higher proportions of northern birds within the Czech Republic compared to the neighbouring areas, making it likely that parents of the reintroduced birds came from northern populations.     

Circulating anti-heat-shock-protein antibodies in normal pregnancy and preeclampsia

It has been previously reported that circulating anti-heat-shock-protein (Hsp) antibody levels are elevated in cardiovascular disorders. The aim of the present study was to determine circulating antihuman Hsp60, antimycobacterial Hsp65, and antihuman Hsp70 antibody levels in healthy pregnant women and preeclamptic patients and to investigate their relationship to the clinical characteristics of the study subjects, as well as to the markers of inflammation (C-reactive protein (CRP)), endothelial activation (von Willebrand factor antigen), or endothelial injury (fibronectin), oxidative stress (malondialdehyde) and to serum Hsp70 levels. Ninety-three preeclamptic patients and 127 normotensive healthy pregnant women were involved in this case control study. Serum anti-Hsp60, anti-Hsp65, anti-Hsp70, and Hsp70 levels were measured with enzyme-linked immunosorbent assay (ELISA). Serum CRP levels were determined by an autoanalyzer using the manufacturer’s kit. Plasma von Willebrand factor antigen levels were quantified by ELISA, while plasma fibronectin concentration by nephelometry. Plasma malondialdehyde levels were measured by the thiobarbituric-acid-based colorimetric assay. For statistical analyses, nonparametric methods were applied. Anti-Hsp60, anti-Hsp65, and anti-Hsp70 antibodies were detected in all of our serum samples. There were no significant differences in serum anti-Hsp60, anti-Hsp65, and anti-Hsp70 antibody levels between the control and preeclamptic groups. Serum levels of Hsp70 and CRP, as well as plasma levels of VWF antigen, fibronectin, and malondialdehyde, were significantly higher in preeclamptic patients than in normotensive healthy pregnant women. Serum anti-Hsp60 antibody levels showed significant correlations with serum anti-Hsp65 antibody levels both in the control and the preeclamptic groups (Spearman R = 0.55 and 0.59; p < 0.001, respectively). However, no other relationship was found between clinical features (maternal age, smoking status, parity, body mass index, gestational age at blood draw, systolic and diastolic blood pressure, gestational age at delivery, and fetal birth weight) and measured laboratory parameters of the study subjects and serum anti-Hsp antibody levels in either study group. In conclusion, anti-Hsp60 and anti-Hsp70 antibodies as naturally occurring autoantibodies are present in the peripheral circulation of healthy pregnant women. Nevertheless, humoral immunity against heat shock proteins was not associated with preeclampsia. Further studies are warranted to explore the role of heat shock proteins and immune reactivity to them in the immunobiology of normal pregnancy and preeclampsia.     

Mitochondria produce reactive nitrogen species via an arginine-independent pathway

We measured the contribution of mitochondrial nitric oxide synthase (mtNOS) and respiratory chain enzymes to reactive nitrogen species (RNS) production. Diaminofluorescein (DAF) was applied for the assessment of RNS production in isolated mouse brain, heart and liver mitochondria and also in a cultured neuroblastoma cell line by confocal microscopy and flow cytometry. Mitochondria produced RNS, which was inhibited by catalysts of peroxynitrite decomposition but not by nitric oxide (NO) synthase inhibitors. Disrupting the organelles or withdrawing respiratory substrates markedly reduced RNS production. Inhibition of complex I abolished the DAF signal, which was restored by complex II substrates. Inhibition of the respiratory complexes downstream from the ubiquinone/ubiquinol cycle or dissipating the proton gradient had no effect on DAF fluorescence. We conclude that mitochondria from brain, heart and liver are capable of significant RNS production via the respiratory chain rather than through an arginine-dependent mtNOS.     

Mice lacking the extracellular matrix adaptor protein matrilin-2 develop without obvious abnormalities.

Matrilins are putative adaptor proteins of the extracellular matrix (ECM) which can form both collagen-dependent and collagen-independent filamentous networks. While all known matrilins (matrilin-1, -2, -3, and -4) are expressed in cartilage, only matrilin-2 and matrilin-4 are abundant in non-skeletal tissues. To clarify the biological role of matrilin-2, we have developed a matrilin-2-deficient mouse strain. Matrilin-2 null mice show no gross abnormalities during embryonic or adult development, are fertile, and have a normal lifespan. Histological and ultrastructural analyses indicate apparently normal structure of all organs and tissues where matrilin-2 is expressed. Although matrilin-2 co-localizes with matrilin-4 in many tissues, Northern hybridization, semiquantitative RT-PCR, immunohistochemistry and biochemical analysis reveal no significant alteration in the steady-state level of matrilin-4 expression in homozygous mutant mice. Immunostaining of wild-type and mutant skin samples indicate no detectable differences in the expression and deposition of matrilin-2 binding partners including collagen I, laminin-nidogen complexes, fibrillin-2 and fibronectin. In addition, electron microscopy reveals an intact basement membrane at the epidermal-dermal junction and normal organization of the dermal collagen fibrils in mutant skin. These data suggest that either matrilin-2 and matrilin-2-mediated matrix-matrix interactions are dispensable for proper ECM assembly and function, or that they are efficiently compensated by other matrix components including wild-type levels of matrilin-4.     

Empirical isotropic chemical shift surfaces

A list of proteins is given for which spatial structures, with a resolution better than 2.5 A, are known from entries in the Protein Data Bank (PDB) and isotropic chemical shift (ICS) values are known from the RefDB database related to the Biological Magnetic Resonance Bank (BMRB) database. The structures chosen provide, with unknown uncertainties, dihedral angles phi and psi characterizing the backbone structure of the residues. The joint use of experimental ICSs of the same residues within the proteins, again with mostly unknown uncertainties, and ab initio ICS(phi,psi) surfaces obtained for the model peptides For-(L-Ala)(n)-NH(2), with n = 1, 3, and 5, resulted in so-called empirical ICS(phi,psi) surfaces for all major nuclei of the 20 naturally occurring alpha-amino acids. Out of the many empirical surfaces determined, it is the 13C(alpha)-1H(alpha) ICS(phi,psi) surface which seems to be most promising for identifying major secondary structure types, alpha-helix, beta-strand, left-handed helix (alpha(D)), and polyproline-II. Detailed tests suggest that Ala is a good model for many naturally occurring alpha-amino acids. Two-dimensional empirical 13C(alpha)-1H(alpha) ICS(phi,psi) correlation plots, obtained so far only from computations on small peptide models, suggest the utility of the experimental information contained therein and thus they should provide useful constraints for structure determinations of proteins.     

The small RNA expression profile of the developing murine urinary and reproductive systems

microRNAs (miRNAs) are small non-coding RNAs with fundamental roles in the regulation of gene expression. miRNAs assemble with Argonaute (Ago) proteins to miRNA-protein complexes (miRNPs), which interact with distinct binding sites on mRNAs and regulate gene expression. Specific miRNAs are key regulators of tissue and organ development and it has been shown in mammals that miRNAs are also involved in the pathogenesis of many diseases including cancer. Here, we have characterized the miRNA expression profile of the developing murine genitourinary system. Using a computational approach, we have identified several miRNAs that are specific for the analyzed tissues or the developmental stage. Our comprehensive miRNA expression atlas of the developing genitourinary system forms an invaluable basis for further functional in vivo studies.     

Haste makes waste but condition matters: molt rate-feather quality trade-off in a sedentary songbird

Background

The trade-off between current and residual reproductive values is central to life history theory, although the possible mechanisms underlying this trade-off are largely unknown. The ‘molt constraint’ hypothesis suggests that molt and plumage functionality are compromised by the preceding breeding event, yet this candidate mechanism remains insufficiently explored.

Methodology/Principal Findings

The seasonal change in photoperiod was manipulated to accelerate the molt rate. This treatment simulates the case of naturally late-breeding birds. House sparrows Passer domesticus experiencing accelerated molt developed shorter flight feathers with more fault bars and body feathers with supposedly lower insulation capacity (i.e. shorter, smaller, with a higher barbule density and fewer plumulaceous barbs). However, the wing, tail and primary feather lengths were shorter in fast-molting birds if they had an inferior body condition, which has been largely overlooked in previous studies. The rachis width of flight feathers was not affected by the treatment, but it was still condition-dependent.

Conclusions/Significance

This study shows that sedentary birds might face evolutionary costs because of the molt rate–feather quality conflict. This is the first study to experimentally demonstrate that (1) molt rate affects several aspects of body feathers as well as flight feathers and (2) the costly effects of rapid molt are condition-specific. We conclude that molt rate and its association with feather quality might be a major mediator of life history trade-offs. Our findings also suggest a novel advantage of early breeding, i.e. the facilitation of slower molt and the condition-dependent regulation of feather growth.     

Human telomeric sequence forms a hybrid-type intramolecular G-quadruplex structure with mixed parallel/antiparallel strands in potassium solution

Human telomeric DNA consists of tandem repeats of the sequence d(TTAGGG). The formation and stabilization of DNA G-quadruplexes in the human telomeric sequence have been shown to inhibit the activity of telomerase, thus the telomeric DNA G-quadruplex has been considered as an attractive target for cancer therapeutic intervention. However, knowledge of the intact human telomeric G-quadruplex structure(s) formed under physiological conditions is a prerequisite for structure-based rational drug design. Here we report the folding structure of the human telomeric sequence in K⁺ solution determined by NMR. Our results demonstrate a novel, unprecedented intramolecular G-quadruplex folding topology with hybrid-type mixed parallel/antiparallel G-strands. This telomeric G-quadruplex structure contains three G-tetrads with mixed G-arrangements, which are connected consecutively with a double-chain-reversal side loop and two lateral loops, each consisting of three nucleotides TTA. This intramolecular hybrid-type telomeric G-quadruplex structure formed in K⁺ solution is distinct from those reported on the 22 nt Tel22 in Na⁺ solution and in crystalline state in the presence of K⁺, and appears to be the predominant conformation for the extended 26 nt telomeric sequence Tel26 in the presence of K⁺, regardless of the presence or absence of Na⁺. Furthermore, the addition of K⁺ readily converts the Na⁺-form conformation to the K⁺-form hybrid-type G-quadruplex. Our results explain all the reported experimental data on the human telomeric G-quadruplexes formed in the presence of K⁺, and provide important insights for understanding the polymorphism and interconversion of various G-quadruplex structures formed within the human telomeric sequence, as well as the effects of sequence and cations. This hybrid-type G-quadruplex topology suggests a straightforward pathway for the secondary structure formation with effective packing within the extended human telomeric DNA. The hybrid-type telomeric G-quadruplex is most likely to be of pharmacological relevance, and the distinct folding topology of this G-quadruplex suggests that it can be specifically targeted by G-quadruplex interactive small molecule drugs.     

Trigonostemons G and H,dinorditerpenoid dimers with axially chiral biaryl linkage from Trigonostemon chinensis

Trigonostemons G and H, two novel dimeric dinorditerpenoids, were isolated from the stem barks of Trigonostemon chinensis. Their planar structures and relative configurations were established by extensive analysis of spectroscopic data. Trigonostemons G and H possess a homodimeric biaryl skeleton obtained from two rearranged chiral nonracemic abietane-type dinorditerpenes through an axially chiral biaryl 11,11′-linkage. Torsional scan and computation of the transition states were carried out to estimate the rotational energy barrier, and the axial chirality (aS) was determined by time-dependent density functional theory (TDDFT) electronic circular dichroism (ECD) calculations. The positive n-π* ECD transitions of the isolated carbonyl chromophore above 300 nm could be used to determine the central chirality of trigonostemon G independently by ECD calculations of the diastereomers.