Sexual reproduction and developmental adaptations in Xanthoria parietina

Thalli of Xanthoria parietina have been grown in cultures in the natural environment. In early phases of development the fungus associates with foreign algae and only later forms a symbiosis with Pseudotrebouxia . The lichen is shown to have a very effective mechanism for distribution by sexual spores followed by relichenization.     

Effect of repeated apoA-IMilano/POPC infusion on lipids, (apo)lipoproteins,and serum cholesterol efflux capacity in cynomolgus monkeys

MDCO-216, a complex of dimeric recombinant apoA-IMilano (apoA-IM) and palmitoyl-oleoyl-phosphatidylcholine (POPC), was administered to cynomolgus monkeys at 30, 100, and 300 mg/kg every other day for a total of 21 infusions, and effects on lipids, (apo)lipoproteins, and ex-vivo cholesterol efflux capacity were monitored. After 7 or 20 infusions, free cholesterol (FC) and phospholipids (PL) were strongly increased, and HDL-cholesterol (HDL-C), apoA-I, and apoA-II were strongly decreased. We then measured short-term effects on apoA-IM, lipids, and (apo)lipoproteins after the first or the last infusion. After the first infusion, PL and FC went up in the HDL region and also in the LDL and VLDL regions. ApoE shifted from HDL to LDL and VLDL regions, while ApoA-IM remained located in the HDL region. On day 41, ApoE levels were 8-fold higher than on day 1, and FC, PL, and apoE resided mostly in LDL and VLDL regions. Drug infusion quickly decreased the endogenous cholesterol esterification rate. ABCA1-mediated cholesterol efflux on day 41 was markedly increased, whereas scavenger receptor type B1 (SRB1) and ABCG1-mediated effluxes were only weakly increased. Strong increase of FC is due to sustained stimulation of ABCA1-mediated efflux, and drop in HDL and formation of large apoE-rich particles are due to lack of LCAT activation.     

A novel locus (RP24) for X-linked retinitis pigmentosa maps to Xq26-27.

Two genetic loci, RP2 and RP3, for X-linked retinitis pigmentosa (XLRP) have been localized to Xp11.3-11.23 and Xp21.1, respectively. RP3 appears to account for 70% of XLRP families; however, mutations in the RPGR gene (isolated from the RP3 region) are identified in only 20% of affected families. Close location of XLRP loci at Xp and a lack of unambiguous clinical criteria do not permit assignment of genetic subtype in a majority of XLRP families; nonetheless, in some pedigrees, both RP2 and RP3 could be excluded as the causative locus. We report the mapping of a novel locus, RP24, by haplotype and linkage analysis of a single XLRP pedigree. The RP24 locus was identified at Xq26-27 by genotyping 52 microsatellite markers spanning the entire X chromosome. A maximum LOD score of 4.21 was obtained with DXS8106. Haplotype analysis assigned RP24 within a 23-cM region between the DXS8094 (proximal) and DXS8043 (distal) markers. Other chromosomal regions and known XLRP loci were excluded by obligate recombination events between markers in those regions and the disease locus. Hemizygotes from the RP24 family have early onset of rod photoreceptor dysfunction; cone receptor function is normal at first, but there is progressive loss. Patients at advanced stages show little or no detectable rod or cone function and have clinical hallmarks of typical RP. Mapping of the RP24 locus expands our understanding of the genetic heterogeneity in XLRP and will assist in development of better tools for diagnosis.     

A chemical,genetic, and structural analysis of the nuclear bile acid receptor FXR

The farnesoid X receptor (FXR) functions as a bile acid (BA) sensor coordinating cholesterol metabolism, lipid homeostasis, and absorption of dietary fats and vitamins. However, BAs are poor reagents for characterizing FXR functions due to multiple receptor independent properties. Accordingly, using combinatorial chemistry we evolved a small molecule agonist termed fexaramine with 100-fold increased affinity relative to natural compounds. Gene-profiling experiments conducted in hepatocytes with FXR-specific fexaramine versus the primary BA chenodeoxycholic acid (CDCA) produced remarkably distinct genomic targets. Highly diffracting cocrystals (1.78 A) of fexaramine bound to the ligand binding domain of FXR revealed the agonist sequestered in a 726 A(3) hydrophobic cavity and suggest a mechanistic basis for the initial step in the BA signaling pathway. The discovery of fexaramine will allow us to unravel the FXR genetic network from the BA network and selectively manipulate components of the cholesterol pathway that may be useful in treating cholesterol-related human diseases.     

Isolation and characterization of the ecdysone receptor and its heterodimeric partner ultraspiracle through development in Sciara coprophila

Regulation of DNA replication is critical, and loss of control can lead to DNA amplification. Naturally occurring, developmentally regulated DNA amplification occurs in the DNA puffs of the late larval salivary gland giant polytene chromosomes in the fungus fly, Sciara coprophila. The steroid hormone ecdysone induces DNA amplification in Sciara, and the amplification origin of DNA puff II/9A contains a putative binding site for the ecdysone receptor (EcR). We report here the isolation, cloning, and characterizing of two ecdysone receptor isoforms in Sciara (ScEcR-A and ScEcR-B) and the heterodimeric partner, ultraspiracle (ScUSP). ScEcR-A is the predominant isoform in larval tissues and ScEcR-B in adult tissues, contrary to the pattern in Drosophila. Moreover, ScEcR-A is produced at amplification but is absent just prior. We discuss these results in relation to the model of ecdysone regulation of DNA amplification.     

Hundred and eighty years of fleet dynamics in the Belgian sea fisheries

Understanding the impact of fisheries on the commercial fish stocks requires detailed catch statistics and data on the dynamics of fleet and catch effort, at least before industrial fishing started. Most time-series on the fleet dynamics start after the 1980s, at times when major changes in fleet characteristics had already taken place. In the present paper, the results of the integration of data on fleet size (from 1830), tonnage (from 1842) and engine power (kW, from 1912) of the Belgian sea fisheries fleet are presented. The decrease in fleet size and changes in overall tonnage and engine power since the beginning of the reconstructed time-series, are quantified. The data show that the decrease in fleet size (?85 %) and in overall engine power (?5 %) was compensated by an increase in average tonnage per vessel (×10 increase) and in average engine power per vessel (×6 increase). The overall fishing effort of the fleet expressed as the total number of days spent at sea has decreased by approximately ?84 % between 1938 and 2010, while the average amount of fish landed per day per vessel (1,000 kg in 2008–2010) has at least doubled in the same period. The data reconstruction provides a unique view on the dynamics in the sea fisheries fleet of Belgium over 180 years and the political and social events associated to these changes.     

Design,construction, and characterization of a second‐generation DARPin library with reduced hydrophobicity

Designed ankyrin repeat proteins (DARPins) are well‐established binding molecules based on a highly stable nonantibody scaffold. Building on 13 crystal structures of DARPin‐target complexes and stability measurements of DARPin mutants, we have generated a new DARPin library containing an extended randomized surface. To counteract the enrichment of unspecific hydrophobic binders during selections against difficult targets containing hydrophobic surfaces such as membrane proteins, the frequency of apolar residues at diversified positions was drastically reduced and substituted by an increased number of tyrosines. Ribosome display selections against two human caspases and membrane transporter AcrB yielded highly enriched pools of unique and strong DARPin binders which were mainly monomeric. We noted a prominent enrichment of tryptophan residues during binder selections. A crystal structure of a representative of this library in complex with caspase‐7 visualizes the key roles of both tryptophans and tyrosines in providing target contacts. These aromatic and polar side chains thus substitute the apolar residues valine, leucine, isoleucine, methionine, and phenylalanine of the original DARPins. Our work describes biophysical and structural analyses required to extend existing binder scaffolds and simplifies an existing protocol for the assembly of highly diverse synthetic binder libraries.     

Health-related quality of life and weight loss among overweight and obese U.S. adults, 2001 to 2002

Objective: To examine the prevalence and association of health‐related quality of life (HRQOL) with trying to lose weight and with weight loss practices (eating fewer calories, physical activity, and both) among overweight and obese U.S. adults ≥ 20 years of age. Research Methods and Procedures: This study used data from the 2001 to 2002 National Health and Nutrition Examination Survey, a continuous annual survey of the civilian non‐institutionalized U.S. population. This analysis included those ≥ 20 years of age with BMI ≥ 25 (n = 2578) who responded to four standard HRQOL measures that assessed general health status and recent physical health, mental health, and activity limitation. Results: Among obese men, but not women, there were significant increasing linear trends in the adjusted prevalence of trying to lose weight as physically unhealthy and activity limitation days increased. Regardless of BMI or HRQOL, reducing calories was a common weight loss practice (66% to 86%). Except for recent activity limitation, respondents with BMI ≥ 35 did not generally differ by HRQOL level in the attainment of recommended physical activity either alone or in combination with reduced calories, whereas those in the BMI 25 to 34.9 groups often differed significantly by HRQOL level. Specifically, increased unhealthy or activity limitation days were associated with reduced prevalence of attained physical activity. Discussion: Our findings indicate an association between trying to lose weight and a greater number of unhealthy days reported by obese men, suggesting that these men may be influenced by traditional clinical weight‐loss counseling that is prompted by weight and comorbidity, whereas women had a high prevalence of trying to lose weight irrespective of weight and HRQOL. Assessment of HRQOL, especially measures that evaluate physical domains, could provide subjective information to assist with weight counseling.