Psychological impact of genetic testing for breast cancer susceptibility in women of Ashkenazi Jewish background: a prospective study

The recognition that the prevalence of three founder mutations in the BRCA1 and BRCA2 genes is over 2% in Ashkenazi Jews has resulted in numerous epidemiological research studies of this ethno-religious group. To determine the effects of incorporating research into clinical practice, a psychological impact study of women participating in an epidemiological study was conducted. Sixty women of Ashkenazi Jewish background who underwent genetic testing for founder mutations were assessed using mailed, self-administered questionnaires with validated measures of psychological outcome. Forty-three women elected to learn their results and 17 women declined to do so. Women who elected to learn their results were also assessed 7-10 days, 4 months, and 12 months after results disclosure. Women who chose to learn their results had significantly higher baseline breast cancer anxiety, compared to those who elected not to learn their results (z = -2.27; p = 0.023). Unaffected women who elected to learn their results showed a significant decrease in breast cancer anxiety 4 months (z = -2.37, p = 0.018) and 12 months (z = -3.06, p = 0.002) post-notification compared to baseline. Genetic testing for mutations common in Ashkenazi Jewish women with result disclosure does not lead to adverse psychological outcomes.     

Comparative analysis detects dependencies among the 5' splice-site positions

Human-mouse comparative genomics is an informative tool to assess sequence functionality as inferred from its conservation level. We used this approach to examine dependency among different positions of the 5' splice site. We compiled a data set of 50,493 homologous human-mouse internal exons and analyzed the frequency of changes among different positions of homologous human-mouse 5' splice-site pairs. We found mutual relationships between positions +4 and +5, +5 and +6, -2 and +5, and -1 and +5. We also demonstrated the association between the exonic and the intronic positions of the 5' splice site, in which a stronger interaction of U1 snRNA and the intronic portion of the 5' splice site compensates for weak interaction of U1 snRNA and the exonic portion of the 5' splice site, and vice versa. By using an ex vivo system that mimics the effect of mutation in the 5' splice site leading to familial dysautonomia, we demonstrated that U1 snRNA base-pairing with positions +6 and -1 is the only functional requirement for mRNA splicing of this 5' splice site. Our findings indicate the importance of U1 snRNA base-pairing to the exonic portion of the 5' splice site.     

Cross-reactivity of some antibodies to human epitopes with shrimp Pandalus borealis proteins: a possible aid in validation and characterization of crustacean cells in vitro

Cell characterization of primary cultures in vertebrates is well established but not in marine invertebrates. This fact is hampering advances in the development of tissue cultures from this species. In the present study, a panel of antibodies to structural proteins, stress proteins, oncogenes and proliferation antigens, developed against mammalian antigens, were tested in paraffin sections of the crustacean Pandalus borealis tissues. Several tissues were analysed: hepatopancreas, gills, ovaries, epithelium under the cuticle and abdominal muscle. Specific antibodies to crustacean proteins are not commercially available. The immunocytochemical results show that antibodies to human epitopes cross-react with antigens in the crustacean Pandalus borealis indicating that some cellular proteins are highly conserved in evolution. Cytokeratin, proliferating cell nuclear antigen, ras and p-glycoprotein were detected by immunocytochemistry in Pandalus borealis. No immunoreactivity for Ki-67 and metallothionein was observed. This system can help in validation and characterization of invertebrate cultures.     

Computerized classification of Mediterranean vegetation using panchromatic aerial photographs

Abstract. Historical aerial photographs are an important source for data on medium- to long-term (10 - 50 yr) vegetation changes. Older photographs are panchromatic, and manual interpretation has traditionally been used to derive vegetation data from such photographs. We present a method for computerized analysis of panchromatic aerial photographs, which enables one to create high resolution, accurate vegetation maps. Our approach is exemplified using two aerial photographs (from 1964 and 1992) of a test area on Mt. Meron, Israel. Spatial resolution (pixel size) of the geo-rectified photos was 0.30 m and spatial accuracy (RMS error) ca. 1 m. An illumination adjustment prior to classification was found to be essential in reducing misclassification error rates. Two classification approaches were employed: a standard maximum-likelihood supervised classifier, and a modification of a supervised classification, which takes into account spectral properties of individual pixels as well as their neighbourhood characteristics. Accuracy of the maximum likelihood classification was 81 % in the 1992 image and 54 % in the 1964 image. The neighbour classifier increased accuracy to 89 % and 82 % respectively. The overall results suggest that computerized analysis of sequences of panchromatic aerial photographs may serve as a valuable tool for the quantification of medium-term vegetation changes.     

Mutations in LRP5 or FZD4 underlie the common familial exudative vitreoretinopathy locus on chromosome 11q

Familial exudative vitreoretinopathy (FEVR) is an inherited blinding disorder of the retinal vascular system. Autosomal dominant FEVR is genetically heterogeneous, but its principal locus, EVR1, is on chromosome 11q13-q23. The gene encoding the Wnt receptor frizzled-4 (FZD4) was recently reported to be the EVR1 gene, but our mutation screen revealed fewer patients harboring mutations than expected. Here, we describe mutations in a second gene at the EVR1 locus, low-density-lipoprotein receptor-related protein 5 (LRP5), a Wnt coreceptor. This finding further underlines the significance of Wnt signaling in the vascularization of the eye and highlights the potential dangers of using multiple families to refine genetic intervals in gene-identification studies.     

Helicobacter pylori 3-deoxy-D-manno-octulosonate-8-phosphate (KDO-8-P) synthase is a zinc-metalloenzyme

3-Deoxy-D-manno-2-octulosonate-8-phosphate (KDO-8-P) synthase catalyzes the aldol-type condensation of phosphoenolpyruvate and D-arabinose-5-phosphate (A-5-P) to produce KDO-8-P and inorganic phosphate. All KDO-8-P synthases, as exemplified by the enzyme from Escherichia coli, were believed not to require a metal cofactor for catalytic activity. However, recent studies have demonstrated that the KDO-8-P synthase from Aquifex aeolicus is a metalloenzyme. Moreover, sequence alignments and phylogenetic analysis of KDO-8-P synthase protein sequences strongly suggested that there is a whole subfamily of KDO-8-P synthases that are also metalloenzymes. One of these putative metalloenzymes is the ortholog from the human pathogen Helicobacter pylori. In order to test this model, we have cloned the kdsa gene encoding H. pylori KDO-8-P synthase, and overexpressed and purified the protein. This enzyme was found to bind one mol Zn/mol monomer, and the removal of this metal by treatment with 2,6-pyridine dicarboxylic acid abolished enzymatic activity. The Zn(2+) in the enzyme could be quantitatively replaced by Cd(2+), which increased the observed k(cat) by approximately 2-fold, and decreased the apparent K(m)(A-5-P) by approximately 6.5-fold. Furthermore, removal of the Zn(2+) from the enzyme did not greatly perturb its circular dichroism spectra. Thus, the divalent metal most likely serves as cofactor directly involved in catalysis.     

A multiscale analysis of herbaceous species richness in a Mediterranean ecosystem

Aims Studies of species distribution patterns traditionally have been conducted at a single scale, often overlooking species–environment relationships operating at finer or coarser scales. Testing diversity-related hypotheses at multiple scales requires a robust sampling design that is nested across scales. Our chief motivation in this study was to quantify the contributions of different predictors of herbaceous species richness at a range of local scales.Methods Here, we develop a hierarchically nested sampling design that is balanced across scales, in order to study the role of several environmental factors in determining herbaceous species distribution at various scales simultaneously. We focus on the impact of woody vegetation, a relatively unexplored factor, as well as that of soil and topography. Light detection and ranging (LiDAR) imaging enabled precise characterization of the 3D structure of the woody vegetation, while acoustic spectrophotometry allowed a particularly high-resolution mapping of soil CaCO 3 and organic matter contents.Important findings We found that woody vegetation was the dominant explanatory variable at all three scales (10, 100 and 1000 m 2), accounting for more than 60% of the total explained variance. In addition, we found that the species richness–environment relationship was scale dependent. Many studies that explicitly address the issue of scale do so by comparing local and regional scales. Our results show that efforts to conserve plant communities should take into account scale dependence when analyzing species richness–environment relationships, even at much finer resolutions than local vs. regional. In addition, conserving heterogeneity in woody vegetation structure at multiple scales is a key to conserving diverse herbaceous communities.     

Refinement of a Translocation Breakpoint Associated with Blepharophimosis–Ptosis–Epicanthus Inversus Syndrome to a 280-kb Interval at Chromosome 3q23

Blepharophimosis syndrome (BPES) is an autosomal dominant disorder of craniofacial development, the features of which include blepharophimosis, ptosis, and epicanthus inversus. Although it has been suggested that BPES is genetically heterogeneous, a major locus for this condition resides at chromosome 3q23. We have previously mapped a translocation breakpoint associated with BPES to the D3S1316–D3S1615 interval. The markers in this region have subsequently been shown to lie in a different order, with the BPES locus mapping to the 1-cM D3S1576 and D3S1316 interval. In the current investigation, a physical map, consisting of 60 yeast artificial chromosome (YAC) clones and 1 bacterial artificial chromosome, that spans this region has been constructed. Ten expressed sequence tags and the cellular retinol-binding protein I locus have been mapped to the contig. YAC end isolation has led to the creation of novel STSs that have been used to reduce the size of the BPES critical region to a 280-kb interval, which has been cloned in two nonchimeric YACs.     

Extensive chordate and annelid macrosynteny reveals ancestral homeobox gene organization

Genes with the homeobox motif are crucial in developmental biology and widely implicated in the evolution of development. The Antennapedia (ANTP)-class is one of the two major classes of animal homeobox genes, and includes the Hox genes, renowned for their role in patterning the anterior-posterior axis of animals. The origin and evolution of the ANTP-class genes are a matter of some debate. A principal guiding hypothesis has been the existence of an ancient gene Mega-cluster deep in animal ancestry. This hypothesis was largely established from linkage data from chordates, and the Mega-cluster hypothesis remains to be seriously tested in protostomes. We have thus mapped ANTP-class homeobox genes to the chromosome level in a lophotrochozoan protostome. Our comparison of gene organization in Platynereis dumerilii and chordates indicates that the Mega-cluster, if it did exist, had already been broken up onto four chromosomes by the time of the protostome-deuterostome ancestor (PDA). These results not only elucidate an aspect of the genome organization of the PDA but also reveal high levels of macrosynteny between P. dumerilii and chordates. This implies a very low rate of interchromosomal genome rearrangement in the lineages leading to P. dumerilii and the chordate ancestor since the time of the PDA.