A new role for PGRP-S (Tag7) in immune defense: lymphocyte migration is induced by a chemoattractant complex of Tag7 with Mts1

PGRP-S (Tag7) is an innate immunity protein involved in the antimicrobial defense systems, both in insects and in mammals. We have previously shown that Tag7 specifically interacts with several proteins, including Hsp70 and the calcium binding protein S100A4 (Mts1), providing a number of novel cellular functions. Here we show that Tag7–Mts1 complex causes chemotactic migration of lymphocytes, with NK cells being a preferred target. Cells of either innate immunity (neutrophils and monocytes) or acquired immunity (CD4⁺ and CD8⁺ lymphocytes) can produce this complex, which confirms the close connection between components of the 2 branches of immune response.     

Production of DON-related trichothecenes byFusarium graminearum Schw from Krasnodarski krai of the USSR

34Fusarium graminearum Schw isolates produced 4-deoxynivalenol to form significant amounts of 4, 7 — dideoxynivalenol and lesser amounts of 4 — deoxynivalenol monoacetates on grain substratesin vitro. This is the first report on the capability a large group of naturally occurring isolates to produce 4,7-dideoxynivalenol. The average levels of 4,7-dideoxynivalenol on rice, corn, barley, and wheat as a substrate were respectively 26.8, 14.0, 12.8, and 10.5% of the level of 4-deoxynivalenol. 4, 7 — dideoxynivalenol was present in all examined naturally contaminated wheat kernel samples at levels of 1.7 to 7.9% of the level of 4-deoxynivalenol. These findings suggest that more attention should be given to the occurrence of 4,7-dideoxynivalenol in cereals.     

Transgene Coplacement and High Efficiency Site-Specific Recombination with the Cre/Loxp System in Drosophila

Studies of gene function and regulation in transgenic Drosophila are often compromised by the possibility of genomic position effects on gene expression. We have developed a method, called transgene coplacement, in which any two sequences can be positioned at exactly the same site and orientation in the genome. Transgene coplacement makes use of the bacteriophage P1 system of Cre/loxP site-specific recombination, which we have introduced into Drosophila. In the presence of a cre transgene driven by a dual hsp70-Mos1 promoter, a white reporter gene flanked by loxP sites is excised with virtually 100% efficiency both in somatic cells and in germ cells. A strong maternal effect, resulting from Cre recombinase present in the oocyte, is observed as white or mosaic eye color in F(1) progeny. Excision in germ cells of the F(1) yields a strong grand-maternal effect, observed as a highly skewed ratio of eye-color phenotypes in the F(2) generation. The excision reactions of Cre/loxP and the related FLP/FRT system are used to create Drosophila lines in which transgenes are at exactly allelic sites in homologous chromosomes.     

Somatoform disorders among patients attending walk-in clinics in Trinidad: prevalence and association with depression and anxiety

Objectives Somatoform disorders are common in international primary care settings, but have been little studied in the developing world. The objective of this study was to determine the prevalence of severe undifferentiated somatoform disorder, and its relationship to depression and anxiety, among patients attending walk-in clinics in Trinidad.Methods The study participants, who were all aged 18 years or older and attending walk-in clinics at 16 randomly selected health centres, were surveyed between May and August 2007 using the PRIME-MD questionnaire.Results There were 594 participants (the response rate was 92%), of whom 72.7% were female. Their ages ranged from 18 to 93 years, and 54.5% were over 50 years of age. In total, 37.2% were married and 25.9% were single. Indo-Trinidadians represented 43.1% and Afro-Trinidadians represented 36% of the study sample; 56.5% of the participants reported that their income was less than US$ 400 per month, and 65.7% were unemployed. At walk-in clinics in Trinidad, the estimated prevalence of severe undifferentiated somatoform disorder was 10.3% (95% CI: 7.86–12.74), that of hypochondriasis was 28.5% (95% CI: 24.9–32.1), and that of body dysmorphic disorder was 15.8% (95% CI: 11.9–18.7). Severe undifferentiated somatoform disorder was statistically significantly associated with gender and ethnicity but not with age, level of education, employment status or income. Chi-square testing found significant associations between the presence of severe undifferentiated somatoform disorder and both depression and anxiety (P < 0.05), between hypochondriasis and both anxiety and depression (P < 0.05), and between body dysmorphic disorder and depression (P < 0.05) but not anxiety. Regression analysis suggested that the demographic features that predicted severe undifferentiated somatoform disorder were being female or Indo-Trinidadian.Conclusions Walk-in clinics in Trinidad that serve older patients on a lower income have a high proportion of patients with somatoform disorders as measured by the PRIME-MD scale. These patients exhibit many features of anxiety and depression. These findings have implications for medical training and service delivery.     

Apoptotic cell death and related gene expression in metastatic tumors of AKR lymphomas of varying malignancy

Resistance to apoptosis may be related to tumor progression, due to the implications it might have on both tumor mass and genetic instability. We compared the tendency to spontaneous apoptosis and the proliferative capacity of metastatic growths of several AKR lymphoma variants (TAU-45, TAU-47, TAU-44, TAU-33, TAU-42 and TAU-46, in the order of increasing metastatic potential). We further compared the expression of several apoptosis-related genes. Cell proliferative capacity did not appear to determine malignant behavior since, on the whole, a decrease in S + G2M fraction was observed with increasing malignancy. Sensitivity to apoptotic cell death decreased with increasing malignancy when comparing the TAU-45, TAU-47, TAU-44 and TAU-33 variants, suggesting a role of reduced apoptosis in this T-cell lymphoma. An increase in Bcl-2 content with increasing aggressiveness among these variants, implicates this protein in this tumor progression-related resistance to apoptosis. However, the two variants of highest malignancy, TAU-42 and TAU-46, did not follow the same trend, since they displayed a relatively high content in apoptotic cells and a low Bcl-2 content. Fas receptor expression did not correlate with tendency to apoptosis, indicating that malignant behavior in the AKR lymphoma does not depend on CD95/Fas/APO1 downregulation. Overexpression of p53 was observed only in one of the variants of lowest malignancy.     

A genomic analysis of Drosophila somatic sexual differentiation and its regulation

In virtually all animals, males and females are morphologically, physiologically and behaviorally distinct. Using cDNA microarrays representing one-third of Drosophila genes to identify genes expressed sex-differentially in somatic tissues, we performed an expression analysis on adult males and females that: (1) were wild type; (2) lacked a germline; or (3) were mutant for sex-determination regulatory genes. Statistical analysis identified 63 genes sex-differentially expressed in the soma, 20 of which have been confirmed by RNA blots thus far. In situ hybridization experiments with 11 of these genes showed they were sex-differentially expressed only in internal genital organs. The nature of the products these genes encode provides insight into the molecular physiology of these reproductive tissues. Analysis of the regulation of these genes revealed that their adult expression patterns are specified by the sex hierarchy during development, and that doublesex probably functions in diverse ways to set their activities.     

Inter-familial relationships of the shorebirds (Aves: Charadriiformes) based on nuclear DNA sequence data

Background  

Phylogenetic hypotheses of higher-level relationships in the order Charadriiformes based on morphological data, partly disagree with those based on DNA-DNA hybridisation data. So far, these relationships have not been tested by analysis of DNA sequence data. Herein we utilize 1692 bp of aligned, nuclear DNA sequences obtained from 23 charadriiform species, representing 15 families. We also test earlier suggestions that bustards and sandgrouses may be nested with the charadriiforms. The data is analysed with methods based on the parsimony and maximum-likelihood criteria.     

The evolution of dosage-compensation mechanisms

Dosage compensation is the process by which the expression levels of sex-linked genes are altered in one sex to offset a difference in sex-chromosome number between females and males of a heterogametic species. Degeneration of a sex-limited chromosome to produce heterogamety is a common, perhaps unavoidable, feature of sex-chromosome evolution. Selective pressure to equalize sex-linked gene expression in the two sexes accompanies degeneration, thereby driving the evolution of dosage-compensation mechanisms. Studies of model species indicate that what appear to be very different mechanisms have evolved in different lineages: the male X chromosome is hypertranscribed in drosophilid flies, both hermaphrodite X chromosomes are downregulated in the nematode Caenorhabditis elegans, and one X is inactivated in mammalian females. Moreover, comparative genomic studies demonstrate that the trans-acting factors (proteins and non-coding RNAs) that have been shown to mediate dosage compensation are unrelated among the three lineages. Some tantalizing similarities in the fly and mammalian mechanisms, however, remain to be explained.