The Z family, a group of transposed human immunoglobulin V kappa genes

A group of highly homologous transposed human V kappa I genes, which we call the Z family, was characterized. To date four members, ZI-ZIV, comprising about 230 kb, have been analyzed on cosmid clones. The largest region (ZI) has a length of 85 kb. The Z regions show extensive homology to each other according to restriction maps and hybridization data. In each Z region a solitary V kappa I gene was found. No V kappa genes of other subgroups were detected by hybridization. The nucleotide sequence of the ZI gene revealed a non-processed V kappa I pseudogene. Hybridization experiments with DNAs from rodent/human cell hybrids and other experimental data indicate that some and possibly all members of the Z family lie outside of the kappa locus which is located on chromosome 2; they have been transposed to other chromosomes. Because of their separation from the J kappa C kappa gene segment, the Z genes can be classified as pseudogenes independent of their sequences. We postulate that the Z family arose by amplification event(s). The Z regions can also be regarded as a small family of very long repetitive sequences.     

Purification partielle et propriétés des amylases de la poire

Three amylases E1, E2 and E3 have been extracted from Passe-Crassane pears pulp and partially purified. A good extraction of these enzymes is obtained only with non ionic detergents. Furthermore, solubilization of amylase E1 needs the use of these compounds. Separation of the 3 amylases is obtained by chromatography on Sephadex G100. E1 and E2 are β-amylases whereas E3 is an α-amylase. The first two have similar kinetic properties and interconversion of one form into the other is possible. It is suggested that the insoluble form E1 is the result of the association of β-amylase E2 with other compounds present in the fruit.     

Unexpected consequences of control: competitive vs. predator release in a four-species assemblage of invasive mammals

Invasive species are frequently the target of eradication or control programmes to mitigate their impacts. However, manipulating single species in isolation can lead to unexpected consequences for other species, with outcomes such as mesopredator release demonstrated both theoretically and empirically in vertebrate assemblages with at least two trophic levels. Less is known about the consequences of species removal in more complex assemblages where a greater number of interacting invaders increases the potential for selective species removal to result in unexpected changes in community structure. Using a replicated Before-After Control-Impact field experiment with a four-species assemblage of invasive mammals we show that species interactions in the community are dominated by competition rather than predation. There was no measurable response of two mesopredators (rats and mice) following control of the top predator (stoats), but there was competitive release of rats following removal of a herbivore (possums), and competitive release of mice following removal of rats.     

High-throughput microsatellite isolation through 454 GS-FLX Titanium pyrosequencing of enriched DNA libraries

Microsatellites (or SSRs: simple sequence repeats) are among the most frequently used DNA markers in many areas of research. The use of microsatellite markers is limited by the difficulties involved in their de novo isolation from species for which no genomic resources are available. We describe here a high-throughput method for isolating microsatellite markers based on coupling multiplex microsatellite enrichment and next-generation sequencing on 454 GS-FLX Titanium platforms. The procedure was calibrated on a model species (Apis mellifera) and validated on 13 other species from various taxonomic groups (animals, plants and fungi), including taxa for which severe difficulties were previously encountered using traditional methods. We obtained from 11,497 to 34,483 sequences depending on the species and the number of detected microsatellite loci ranged from 199 to 5791. We thus demonstrated that this procedure can be readily and successfully applied to a large variety of taxonomic groups, at much lower cost than would have been possible with traditional protocols. This method is expected to speed up the acquisition of high-quality genetic markers for nonmodel organisms.     

Plasma Peptide Biomarker Discovery for Amyotrophic Lateral Sclerosis by MALDI –TOF Mass Spectrometry Profiling

The diagnostic of Amyotrophic lateral sclerosis (ALS) remains based on clinical and neurophysiological observations. The actual delay between the onset of the symptoms and diagnosis is about 1 year, preventing early inclusion of patients into clinical trials and early care of the disease. Therefore, finding biomarkers with high sensitivity and specificity remains urgent. In our study, we looked for peptide biomarkers in plasma samples using reverse phase magnetic beads (C18 and C8) and MALDI-TOF mass spectrometry analysis. From a set of ALS patients (n=30) and healthy age-matched controls (n=30), C18- or C8-SVM-based models for ALS diagnostic were constructed on the base of the minimum of the most discriminant peaks. These two SVM-based models end up in excellent separations between the 2 groups of patients (recognition capability overall classes > 97%) and classify blinded samples (10 ALS and 10 healthy age-matched controls) with very high sensitivities and specificities (>90%). Some of these discriminant peaks have been identified by Mass Spectrometry (MS) analyses and correspond to (or are fragments of) major plasma proteins, partly linked to the blood coagulation.     

Angiotensin II acts through the angiotensin 1a receptor to upregulate pendrin

Pendrin is an anion exchanger expressed in the apical regions of B and non-A, non-B intercalated cells. Since angiotensin II increases pendrin-mediated Cl(-) absorption in vitro, we asked whether angiotensin II increases pendrin expression in vivo and whether angiotensin-induced hypertension is pendrin dependent. While blood pressure was similar in pendrin null and wild-type mice under basal conditions, following 2 wk of angiotensin II administration blood pressure was 31 mmHg lower in pendrin null than in wild-type mice. Thus pendrin null mice have a blunted pressor response to angiotensin II. Further experiments explored the effect of angiotensin on pendrin expression. Angiotensin II administration shifted pendrin label from the subapical space to the apical plasma membrane, independent of aldosterone. To explore the role of the angiotensin receptors in this response, pendrin abundance and subcellular distribution were examined in wild-type, angiotensin type 1a (Agtr1a) and type 2 receptor (Agtr2) null mice given 7 days of a NaCl-restricted diet (< 0.02% NaCl). Some mice received an Agtr1 inhibitor (candesartan) or vehicle. Both Agtr1a gene ablation and Agtr1 inhibitors shifted pendrin label from the apical plasma membrane to the subapical space, independent of the Agtr2 or nitric oxide (NO). However, Agtr1 ablation reduced pendrin protein abundance through the Agtr2 and NO. Thus angiotensin II-induced hypertension is pendrin dependent. Angiotensin II acts through the Agtr1a to shift pendrin from the subapical space to the apical plasma membrane. This Agtr1 action may be blunted by the Agtr2, which acts through NO to reduce pendrin protein abundance.     

Natriuretic peptides and endothelin-1 in patients undergoing coronary artery bypass grafting

Off-pump coronary artery bypass grafting (CABG) is an alternative to conventional CABG using cardiopulmonary bypass. Off-pump technique reduces the complications of CABG performed with extracorporeal circulatory assistance (Lancey et al. 2000; Mack et al. 2004a,b). The object of this study was to compare peri- and postoperative time courses of vasoactive peptides - atrial natriuretic poptide (ANP), brain natriuretic poptide (BNP) and endothelin-1 (ET-1) in off-pump versus on-pump CABG. 22 patients, who underwent on-pump (group A, n = 11) or off-pump CABG (group B, n = 11) were studied. The peri- and postoperative time courses of plasma ANP and BNP were similar in both groups. A statistically significant difference between ET-1 plasma level 2 h after surgery in the group A and ET-1 plasma level 2 h after surgery in the group B (2.46 + or - 1.14 pg/ml/Ht versus 0.74 + or - 0.09 pg/ml/Ht, p < 0.0001) was found. Different CABG techniques were not associated with significant changes in peri- and postoperative plasma ANP and BNP. By contrast, plasma ET-1 significantly rose in the group A 2 h after surgery, indicating endothelial damage.