Laser microdissection of grapevine leaf phloem infected by stolbur reveals site‐specific gene responses associated to sucrose transport and metabolism

Bois Noir is an emergent disease of grapevine that has been associated to a phytoplasma belonging to the XII‐A stolbur group. In plants, phytoplasmas have been found mainly in phloem sieve elements, from where they spread moving through the pores of plates, accumulating especially in source leaves. To examine the expression of grapevine genes involved in sucrose transport and metabolism, phloem tissue, including sieve element/companion cell complexes and some parenchyma cells, was isolated from healthy and infected leaves by means of laser microdissection pressure catapulting (LMPC). Site‐specific expression analysis dramatically increased sensitivity, allowing us to identify specific process components almost completely masked in whole‐leaf analysis. Our findings showed decreased phloem loading through inhibition of sucrose transport and increased sucrose cleavage activity, which are metabolic changes strongly suggesting the establishment of a phytoplasma‐induced switch from carbohydrate source to sink. The analysis focused at the infection site also showed a differential regulation and specificity of two pathogenesis‐related thaumatin‐like genes (TL4 and TL5) of the PR‐5 family.     

Solute Accumulation by Grape Pericarp Cells: V. RELATIONSHIP TO BERRY SIZE AND THE EFFECTS OF DEFOLIATION

We have studied the accumulation of water, dry matter (DM) andglucose and fructose (G + F) in selected grape berries cv. Dolcettoof varying initial size growing on leafed and defoliated vines.The first measurements at 2 d after veraison were obtained non-destructivelyfrom correlations with linear dimensions and deformability;the final measurements were made when the berries were harvested13 d later. The increments in DM and G + F per pericarp increased with initialberry size thus discounting an hypothesis of an equal amountof solutes supplied to all berries. The increments in weightof DM and G + F per increment of pericarp volume were constantin berries of different size, supporting an hypothesis of acontrol determined by concentration in the solution availablefor accumulation in all berries. Defoliation reduced the incrementsper pericarp and per g fr. wt. by about the same proportionand its effects were consistent with the above interpretations. Key words: Grape pericarp, sugar accumulation, phloem unloading, Vitis vinifera.     

Development of microsatellite markers for the Mediterranean gorgonian coral Corallium rubrum

Corallium rubrum, an endemic Mediterranean gorgonian coral, has undergone an intensive exploitation leading to the extinction of local commercial banks and changes in the structure and dynamics of coastal populations. Management and conservation of this species requires a better understanding of the genetic structuring and connectivity among populations. With this aim, seven microsatellite loci have been isolated. All loci were polymorphic with allele numbers ranging from five to 26 and observed heterozygosity ranging from 0.18 to 0.68. Significant deviations from Hardy–Weinberg expected genotype frequencies due to heterozygote deficiency were detected at all loci.     

Chromosomal speciation and phenotypic evolution in the house mouse

Chromosomal races of the house mouse (Mus musculus domesticus) in Valtellina and Orobian Alps (Northern Italy) are known for their very fast raciation. Here we present a study using geometric morphometries on size and shape changes in the skull and the mandible of three races (Orobian, Upper Valtellina, Poschiavo) occurring in this area and forming a presumably monophyletic group. One of the races (Upper Valtellina) went extinct recently in an area of sympatry with the Poschiavo race, so that data on genetics (chromosomes and allozymes), behaviour and morphology were available to investigate causes of phenotypic divergence during speciation with a recent extinction event. The evaluation of partial warp scores and the uniform component shows that morphological changes have been fast and that these races can be recognized on the basis of skull shape. Patterns of evolution in shape changes were visualized by combining the chromosomal phylogeny and shape space, summarizing therefore both the phenetic and cladistic relationships. Shape changes follow the cladogenetic sequence depicted by chromosomal fusions. The examination of Procrustes distances shows that the different parts of the skull evolved at different rates after speciation, with shifts in the integration of the various structures (olfactory, auditory, feeding, visualization, etc.). Among the possible causes, aggressive behaviour was advocated for sudden changes in the shape of the skull.     

Monomorphic Region of the Serotonin Transporter Promoter Gene in New World Monkeys

Genetic variation in the human serotonin system has long been studied because of its functional consequences and links to various neuropsychiatric and behavior‐related disorders. Among non‐human primates, the common marmosets (Callithrix jacchus) and tufted capuchins monkeys (Cebus apella) are becoming increasingly used as models to study the effects of genes, environments, and their interaction on physiology and complex behavior. In order to investigate the independent functions of and potential interactions between serotonin‐related genes, anxiety and neuropsychiatric disorders, we analyzed the presence and variability of the serotonin transporter gene‐linked polymorphic region (5‐HTTLPR) in marmoset and capuchin monkeys. By PCR and using heterologous primers from the human sequence, we amplified and then sequenced the corresponding 5‐HTT region in marmosets and capuchins. The resulting data revealed the presence of a tandem repeat sequence similar to that described in humans, but unlike humans and other Old World primates, no variable length alleles were detected in these New World monkeys, suggesting that if serotonin transporter is involved in modulating behavior in these animals it does so through different molecular mechanisms. Am. J. Primatol. 74:1028‐1034, 2012. © 2012 Wiley Periodicals, Inc.     

Serum Clara cell protein (CC16) in healthy young smokers

The CC16 microprotein is the main secretory product of Clara cells, which are epithelial cells lining lung airways. In crossing through the bronchoalveolar/blood barrier, CC16 diffuses passively into plasma. Serum CC16 (sCC16) has recently been proposed as a biomarker for detecting Clara cell impairments. The aim of this study was to assess if sCC16 concentrations are reduced in a group of healthy young smokers. A group of 118 healthy young males volunteered to take part in the study. Each subject answered a questionnaire, and provided blood and urine samples. Serum CC16, urinary cotinine and creatinine were measured. Median serum CC16 concentrations were lower in smokers than in non-smokers (11.3 mug l^-1 vs 14.6 mug l^-1; p = 0.005; N = 89 and 29, respectively) but did not correlate with either the daily or the life-time cigarette consumption, or with urinary cotinine concentrations. sCC16 did not correlate with age or body mass index in the whole study population or in the groups of smokers and non-smokers. These results suggest the reduction in sCC16 concentrations in a group of healthy young smokers may be an early effect of cigarette smoking.     

Actin mRNA Levels and Actin Synthesis During the Encystation of Entamoeba invadens

ABSTRACT. Parasitic amebas propagate among hosts through cysts, the resistant forms in their life cycle. In spite of their key role in infection, little is known about the encystation process and the mechanisms involved in reaching this stage. Two features drastically affected by encystation are motility and cell shape, both of which are determined by the cytoskeleton, composed mainly of actin in these organisms. Therefore, we studied the occurrence and relative levels of actin and actin synthesis during encystation of Entamoeba invadens. Using a cDNA actin probe obtained from a library of E. histolytica and a monoclonal antibody against actin, we found that, while the total actin levels sharply decrease as encystation proceeds, the levels of actin mRNA are reduced only in mature cysts. Moreover, actin synthesis does not take place in precysts and the later stages of cyst formation. In contrast, the levels of other proteins remain stable in trophozoites, precysts and cysts, and stage specific peptides are actively synthesized in precysts. The results indicate that encystation is accompanied by a preferential down-regulation of actin synthesis and a decrease in actin levels. The reorganization of the cytoskeleton occurring as trophozoites transform into round, quiescent cells, could be a regulatory factor in the observed changes.