Sequence Comparisons of Odorant Receptors among Tortricid Moths Reveal Different Rates of Molecular Evolution among Family Members

In insects, odorant receptors detect volatile cues involved in behaviours such as mate recognition, food location and oviposition. We have investigated the evolution of three odorant receptors from five species within the moth genera Ctenopseustis and Planotrotrix, family Tortricidae, which fall into distinct clades within the odorant receptor multigene family. One receptor is the orthologue of the co-receptor Or83b, now known as Orco (OR2), and encodes the obligate ion channel subunit of the receptor complex. In comparison, the other two receptors, OR1 and OR3, are ligand-binding receptor subunits, activated by volatile compounds produced by plants - methyl salicylate and citral, respectively. Rates of sequence evolution at non-synonymous sites were significantly higher in OR1 compared with OR2 and OR3. Within the dataset OR1 contains 109 variable amino acid positions that are distributed evenly across the entire protein including transmembrane helices, loop regions and termini, while OR2 and OR3 contain 18 and 16 variable sites, respectively. OR2 shows a high level of amino acid conservation as expected due to its essential role in odour detection; however we found unexpected differences in the rate of evolution between two ligand-binding odorant receptors, OR1 and OR3. OR3 shows high sequence conservation suggestive of a conserved role in odour reception, whereas the higher rate of evolution observed in OR1, particularly at non-synonymous sites, may be suggestive of relaxed constraint, perhaps associated with the loss of an ancestral role in sex pheromone reception

Framingham-based Tools to Calculate the Global Risk of Coronary Heart Disease: A Systematic Review of Tools for Clinicians

PURPOSE: To examine the features of available Framingham-based risk calculation tools and review their accuracy and feasibility in clinical practice. DATA SOURCES: medline, 1966–April 2003, and the google search engine on the Internet. TOOL AND STUDY SELECTION: We included risk calculation tools that used the Framingham risk equations to generate a global coronary heart disease (CHD) risk. To determine tool accuracy, we reviewed all articles that compared the performance of various Framingham-based risk tools to that of the continuous Framingham risk equations. To determine the feasibility of tool use in clinical practice, we reviewed articles on the availability of the risk factor information required for risk calculation, subjective preference for 1 risk calculator over another, or subjective ease of use. DATA EXTRACTION: Two reviewers independently reviewed the results of the literature search, all websites, and abstracted all articles for relevant information. DATA SYNTHESIS: Multiple CHD risk calculation tools are available, including risk charts and computerized calculators for personal digital assistants, personal computers, and web-based use. Most are easy to use and available without cost. They require information on age, smoking status, blood pressure, total and HDL cholesterol, and the presence or absence of diabetes. Compared to the full Framingham equations, accuracy for identifying patients at increased risk was generally quite high. Data on the feasibility of tool use was limited. CONCLUSIONS: Several easy-to-use tools are available for estimating patients' CHD risk. Use of such tools could facilitate better decision making about interventions for primary prevention of CHD, but further research about their actual effect on clinical practice and patient outcomes is required. DISCLOSURE: Drs. Sheridan and Pignone have participated in the development of Heart-to-Heart, one of the risk tools evaluated within. They have also received speaking and consulting fees from Bayer, Inc. Bayer, Inc. has licensed the Heart-to-Heart tool