Males of the predatory mirid bug Macrolophus caliginosus exploit plant volatiles induced by conspecifics as a sexual synomone

The olfactory responses of male and female Macrolophus caliginosus Wagner (Heteroptera: Miridae) adults towards volatiles from green bean plants previously exposed to feeding by conspecifics and to direct odours from conspecifics were tested in a Y-tube olfactometer. Female M. caliginosus did not respond to volatiles from plants exposed to mirid feeding or to odours emitted directly by adult mirids. In contrast, male mirid bugs were attracted both to volatiles from plants previously exposed to feeding by conspecific females and to odours emitted by conspecifics only with a marginally significant preference for the former. The gas chromatography-mass spectrometry analysis showed that mirid feeding induced the release of 11 additional compounds as compared to the volatiles emitted from clean plants. Three of these substances (5-ethyl-2(5H)-furanone, Z-3-hexenyl tiglate, and E,E-α-farnesene) were released only after feeding by females. Furthermore, 21 compounds were identified in volatiles emitted directly by mirids, 12 of which were unique to the mirids (i.e., not present in clean plants or plants previously exposed to mirid feeding). The results suggest that female-specific herbivore-induced plant volatiles play a role as mate-finding cues by the male mirids. The ecological implications of the findings are discussed, and the term ‘sexual synomone’ is introduced.     

Loss of STOP Protein Impairs Peripheral Olfactory Neurogenesis

Background

STOP (Stable Tubulin-Only Polypeptide) null mice show behavioral deficits, impaired synaptic plasticity, decrease in synaptic vesicular pools and disturbances in dopaminergic transmission, and are considered a neurodevelopmental model of schizophrenia. Olfactory neurons highly express STOP protein and are continually generated throughout life. Experimentally-induced loss of olfactory neurons leads to epithelial regeneration within two months, providing a useful model to evaluate the role played by STOP protein in adult olfactory neurogenesis.

Methodology/Principal Findings

Immunocytochemistry and electron microscopy were used to study the structure of the glomerulus in the main olfactory bulb and neurogenesis in the neurosensorial epithelia. In STOP null mice, olfactory neurons showed presynaptic swellings with tubulovesicular profiles and autophagic-like structures. In olfactory and vomeronasal epithelia, there was an increase in neurons turnover, as shown by the increase in number of proliferating, apoptotic and immature cells with no changes in the number of mature neurons. Similar alterations in peripheral olfactory neurogenesis have been previously described in schizophrenia patients. In STOP null mice, regeneration of the olfactory epithelium did not modify these anomalies; moreover, regeneration resulted in abnormal organisation of olfactory terminals within the olfactory glomeruli in STOP null mice.

Conclusions/Significance

In conclusion, STOP protein seems to be involved in the establishment of synapses in the olfactory glomerulus. Our results indicate that the olfactory system of STOP null mice is a well-suited experimental model (1) for the study of the mechanism of action of STOP protein in synaptic function/plasticity and (2) for pathophysiological studies of the mechanisms of altered neuronal connections in schizophrenia.     

A biochemical study on the level of lipids and glycoproteins in the serum and platelets of liver cirrhotic bleeders

Bleeding complication and abnormal platelet functions are associated with liver cirrhosis. The aim of the present investigation was to assess the functional integrity of platelets in terms of lipids like cholesterol and phospholipids, glycoproteins and membrane-bound enzymes. Liver cirrhotic patients with bleeding complications were studied. Age and sex matched normal healthy volunteers were also involved in this study as a control group. Levels of cholesterol, phospholipids, glycoproteins and adenosine triphosphatases were assessed in isolated platelet membrane fraction. The level of glycoproteins and the activity of adenosine triphosphatases were found to be decreased significantly in cirrhotic patients. The cholesterol/phospholipid ratio was found to be altered significantly, indicating an alteration in the fluidity of platelet membrane. The results of this study reveal that the functional impairment of platelets in liver cirrhotic patients which is responsible for their bleeding tendency might also be due to altered lipid and enzyme levels in platelet membrane.     

Promotion of sustainable capture fisheries and aquaculture in Asian reservoirs and lakes

A collaborative international project funded by the European Union's INCO-DC programme is undertaking limnological, fish biological, environmental and socio-economic research in five tropical lakes and reservoirs in Sri Lanka, Thailand and the Philippines over the period 1998–2001. The aim is to determine their trophic structure and their capacity to sustain both their existing fisheries and present and future aquaculture. In some cases, these activities could potentially be expanded for the benefit of rural communities and of the local market within the bounds of social and environmental sustainability. This paper describes the concepts and methods involved in this innovative multidisciplinary project which aims to integrate limnological, fisheries and socio-economic issues in a comparative approach involving Asian and European research teams.Deceased.     

An analysis approach to identify specific functional sites in orthologous proteins using sequence and structural information: Application to neuroserpin reveals regions that differentially regulate inhibitory activity

The analysis of sequence conservation is commonly used to predict functionally important sites in proteins. We have developed an approach that first identifies highly conserved sites in a set of orthologous sequences using a weighted substitution‐matrix‐based conservation score and then filters these conserved sites based on the pattern of conservation present in a wider alignment of sequences from the same family and structural information to identify surface‐exposed sites. This allows us to detect specific functional sites in the target protein and exclude regions that are likely to be generally important for the structure or function of the wider protein family. We applied our method to two members of the serpin family of serine protease inhibitors. We first confirmed that our method successfully detected the known heparin binding site in antithrombin while excluding residues known to be generally important in the serpin family. We next applied our sequence analysis approach to neuroserpin and used our results to guide site‐directed polyalanine mutagenesis experiments. The majority of the mutant neuroserpin proteins were found to fold correctly and could still form inhibitory complexes with tissue plasminogen activator (tPA). Kinetic analysis of tPA inhibition, however, revealed altered inhibitory kinetics in several of the mutant proteins, with some mutants showing decreased association with tPA and others showing more rapid dissociation of the covalent complex. Altogether, these results confirm that our sequence analysis approach is a useful tool that can be used to guide mutagenesis experiments for the detection of specific functional sites in proteins. Proteins 2015; 83:135–152. © 2014 Wiley Periodicals, Inc.