FIGURE 2.

FOXP2 protein expression in SH-SY5Y cells. (A) Representative Western blot illustrating that anti-FOXP2 antibody detected no protein in parental cells, indicative of absent endogenous expression. Moreover, there was no FOXP2 detectable in cells carrying empty vector (pcDNA3). In contrast, bands were recognized in SH-SY5Y cells stably transfected with pcDNA3-hsaFOXP2, -ptrFOXP2, -mmuFOXP, and -cjaFOXP2 (all without FLAG tag), thereby indicating similar levels of exogenous FOXP2 expression. Purified lysates were run on an SDS-PAGE gel, transferred to PVDF membrane, and successively hybridized with the respective antibodies. Lower panel: β-actin served as a standard for protein load. (B) Densitometric analysis of FOXP2 levels. The given measurements refer to biological replicates I–III (with two technical replicates, each) of the conditions labeled in (A). Maximum (Max.) fold-difference corresponds to the ratio of the most extreme pair of mean expression levels (m/m) between hsaFOXP2-overexpressing cells and cells expressing non-human FOXP2 (here: mmuFOXP2). cja, marmoset (Callithrix jacchus); hsa, human (Homo sapiens); mmu, Rhesus monkey (Macaca mulatta); ptr, chimpanzee (Pan troglodytes).