In the previous studies the hybridization between the probes and single stranded clones were performed at temperatures superior to 50°C, thus under very stringent conditions, reducing the possibility of selection of clones due to mismatches.
On the one hand, there is the view that more stringent EPL reduces TFP.
For Group 1 subjects, this stringent threshold reduced the number of cases down to 115 (37 males and 78 females) with a mean of 29.1 years (range, 17 48).
These stringent criteria reduced the dataset that entered the final analysis to 6 model sequences, 14 observer sequences and 21 non-observer sequences.
These stringent criteria reduced the number of primer pairs in the working set to 99.
These more stringent standards reduce the coverage and thus the power, but the observed patterns remain (supplementary table S3, Supplementary Material online).
Setting more stringent cutoffs reduces the coverage too much: r ≥ 0.70 includes only ~26%% of the gene loci; r ≥ 0.80 includes only ~6%%.
Despite the more stringent threshold reduced the number of genes under analysis, we obtained very similar COG results (Additional file 18: Table S13).
More stringent thresholds reduced the value range of the parameter motifs, but the resultant minor changes did not significantly affect the main findings (see Discussion).
This criterion of requiring a one-to-one orthologous relationship in all the additional species is very stringent and reduces greatly the number of gene pairs for our analysis.
