The genetic architecture of sexually selected traits in two natural populations of Drosophila montana

The work was supported by the National Environment Research Council (grant NE/E015255/1 to MGR and RKB) and the Academy of Finland (project 132619 to AH).We investigated the genetic architecture of courtship song and cuticular hydrocarbon traits in two phygenetically distinct populations of Drosophila montana. To study natural variation in these two important traits, we analysed within-population crosses among individuals sampled from the wild. Hence, the genetic variation analysed should represent that available for natural and sexual selection to act upon. In contrast to previous between-population crosses in this species, no major quantitative trait loci (QTLs) were detected, perhaps because the between-population QTLs were due to fixed differences between the populations. Partitioning the trait variation to chromosomes suggested a broadly polygenic genetic architecture of within-population variation, although some chromosomes explained more variation in one population compared with the other. Studies of natural variation provide an important contrast to crosses between species or divergent lines, but our analysis highlights recent concerns that segregating variation within populations for important quantitative ecological traits may largely consist of small effect alleles, difficult to detect with studies of moderate power.PostprintPeer reviewe

Daily Liquorice Consumption for Two Weeks Increases Augmentation Index and Central Systolic and Diastolic Blood Pressure

<div><p>Background</p><p>Liquorice ingestion often elevates blood pressure, but the detailed haemodynamic alterations are unknown. We studied haemodynamic changes induced by liquorice consumption in 20 subjects versus 30 controls with average blood pressures of 120/68 and 116/64 mmHg, respectively.</p><p>Methods</p><p>Haemodynamic variables were measured in supine position before and after two weeks of liquorice consumption (daily glycyrrhizin dose 290–370 mg) with tonometric recording of radial blood pressure, pulse wave analysis, and whole-body impedance cardiography. Thirty age-matched healthy subjects maintaining their normal diet were studied as controls.</p><p>Results</p><p>Two weeks of liquorice ingestion elevated peripheral and central systolic and diastolic blood pressure (by 7/4 and 8/4 mmHg, 95% confidence intervals [CI] 2-11/1-8 and 3-13/1-8, respectively, <i>P</i><0.05), and increased extracellular volume by 0.5 litres (<i>P</i><0.05 versus controls). Also augmentation index adjusted to heart rate 75/min (from 7% to 11%, 95% CI for change 0.3-7.5, <i>P</i><0.05) and aortic pulse pressure (by 4 mmHg, 95% CI 1-7, <i>P</i><0.05) were elevated indicating increased wave reflection from the periphery. In contrast, peripheral (−3/−0.3 mmHg) and central blood pressure (−2/−0.5 mmHg), aortic pulse pressure (−1 mmHg), and augmentation index adjusted to heart rate 75/min (from 9% to 7%) decreased numerically but not statistically significantly without changes in extracellular volume in the control group. Heart rate, systemic vascular resistance, cardiac output, and pulse wave velocity did not differ between the groups.</p><p>Conclusions</p><p>Two weeks of daily liquorice consumption increased extracellular volume, amplified pressure wave reflection from the periphery, and elevated central systolic and diastolic blood pressure.</p><p>Trial Registration</p><p>EU Clinical Trials Register EudraCT 2006-002065-39</p><p>ClinicalTrials.gov <a href="http://clinicaltrials.gov/ct2/show/NCT01742702" target="_blank">NCT01742702</a></p></div

Flow diagram of the study.

<p>Flow diagram of the study.</p

Demographic data and laboratory values at baseline.

<p>All other values are mean ± SD except for sex, which shows the number of subjects.</p><p>*Blood samples for fasting plasma values were not obtained from one subject.</p

Changes in weight, extracellular water, brachial office systolic and diastolic blood pressure, plasma aldosterone and plasma potassium after two weeks of liquorice ingestion.

<p>All values are mean ± SD.</p><p>*Blood samples for fasting plasma values were not obtained from one subject.</p>†<p><i>P</i> = 0.02 and ^‡<i>P</i><0.001 versus the corresponding value before liquorice diet.</p>#<p>Two normotensive and normokalemic subjects showed divergent serum aldosterone concentrations (6138 and 3720 pmol/l). If these subjects were excluded from the analysis, mean serum aldosterone concentration in the normal diet group was 548±340 pmol/l (p = 0.78 between groups).</p

Aortic pulse pressure, augmentation index, and pulse wave velocity, liquorice diet versus normal diet.

<p>Grey lines represent each individual, thick black line represents mean values of each variable. <i>P</i> values are for the difference in the change of each variable between liquorice diet versus normal diet, <i>P</i> values in brackets are for the change within each group, n = 20 and 30 in the liquorice and normal diet groups, respectively.</p

Heart rate, cardiac index, systemic vascular resistance index, liquorice diet versus normal diet.

<p>Grey lines represent each individual, thick black line represents mean change of each variable. <i>P</i> values are for the difference in the change of each variable between liquorice diet versus normal diet, <i>P</i> values in brackets are for the change within each group, n = 20 and 30 in the liquorice and normal diet groups, respectively.</p

Radial and aortic blood pressure, liquorice diet versus normal diet.

<p>Grey lines represent each individual, thick black line represents mean values of each variable. SBP, systolic blood pressure; DBP, diastolic blood pressure; <i>P</i> values between graphs are for the difference in the change of each variable between liquorice diet versus normal diet, <i>P</i> values in brackets are for the change within each group, n = 20 and 30 in the liquorice and normal diet groups, respectively.</p