Since we expected susceptibility to lead to be dependent on genetic background, we performed dose-response studies on a sample of 10 randomly selected DGRP lines from the total population of 200 lines to establish an optimal concentration for analysis across the DGRP.
Phenotypic Variation in Sensitivity of Development Time and Viability to Lead Exposure in the DGRP
We measured development time and viability of larvae from 200 DGRP lines, which were healthy and easily reared, on standard medium and medium supplemented with 0.
Phenotypic Variation in Sensitivity of Activity to Lead Exposure in the DGRP
We analysed adult locomotor activity as a proxy for neural function in 166 DGRP lines that were able to produce enough adult flies when reared on 0.
Most DGRP lines develop faster during the larval stage and have higher viability to adulthood on control food than food supplemented with lead acetate.
We took advantage of natural variants segregating in the DGRP to identify DNA sequence variants associated with susceptibility to lead toxicity.
Whereas some lines appeared unaffected by exposure to lead acetate, 24 DGRP lines did not develop at all on lead-supplemented medium.
This percentage is similar to functional validation rates obtained with previous GWA studies on the DGRP (Jordan et al.
Since any variation in construction price is revealed early in the PPP project (often within the first 3 years of typically 15-40 year PPP agreements) and, in PPP contracts, construction risk is nearly always fully assigned to the private sector partner and is considered to represent a substantial proportion of the overall risk transfer achieved in a PPP, it seems to be a convenient indicator (European Commission DGRP, 2003).
European Commission DGRP (2003) Guidelines for successful public-private partnerships, Directorate General regional Policy--DGRP, Brussels.
European Commission DGRP (2004) Resource book on PPP case studies, Directorate General regional Policy--DGRP, Brussels.