FIGURE 7.

Increasing ERK-mediated feedback impairs GnRH sensing. Panel A, data from cells treated and imaged as in Fig. 1, except that they were transduced with Ad WT DUSP5myc (filled circles) or Ad R53A/R54A DUSP5 myc (open circles) at 4 pfu/nl. The data are pooled from three separate experiments, each with triplicate wells and at least three fields of view per well (mean ± S.E., n = 3). Panel B, corresponding I(ppERK;GnRH) values (mean ± S.E., n = 3). Panel C, corresponding myc expression levels in cells receiving 10⁻⁷ m GnRH (mean ± S.E., n = 3, the dashed line shows the background stain intensity). A, two way ANOVAs of the ppERK measures revealed significant differences between WT DUSP5 myc- and R53A/R54A DUSP5 myc-expressing cells at all times. B, similar ANOVAs of MI measures revealed a significant difference between WT DUSP5-myc and R53A/R54A DUSP5-myc expressing cells (p < 0.01), and post hoc Bonferroni tests revealed significant differences at all time points (*, p < 0.05; **, p < 0.01). One way ANOVAs of the myc data (C) revealed time as a significant source of variation, and post hoc Dunnett's tests revealed significant increases at 30 and 60 min (compared with 0 min) for each construct.