Figure 1. Quantitative trait loci (QTL), probabilistic trait loci (PTL), and single cell (sc)PTL effects.
In each case, two genotypes at a given locus are compared, as indicated by the color outline of individuals (green versus purple). (A) The locus is a QTL and the purple genotype increases the trait value, as indicated by the size of individuals. (B) The genotype is a PTL and the purple genotype increases the trait variance without changing the mean trait value of individuals. (C) Individual cells of a tissue are represented by dots, colored by their value of a single cell quantitative trait. Here, the locus is a scPTL: the purple genotype increases single cell trait variance within the tissue. This may or may not change the macroscopic phenotype of individuals.