Figure 5. Naturally-aged eggs show a marked reduction in oscillation number following parthenogenetic activation with SrCl₂.

(a,b) Typical SrCl₂-induced oscillatory patterns in young and naturally-aged eggs. (b) Note that two different oscillatory responses were observed for aged eggs. i) 61.5% of aged eggs oscillated for the duration of imaging (left panel). ii) 38.5% of aged eggs ceased oscillating prematurely (right panel). (c) Quantification of the number of oscillations in the first two hours in young (n = 40) and aged (n = 13) eggs revealed a marked reduction in oscillation frequency with maternal age (P < 0.0001). (d) Quantification of the fold-change fluorescence ratio in young (n = 40) and aged (n = 13) eggs revealed oscillation amplitude is unaffected by age (P = 0.7). Experiments performed in Ca²⁺ -free media. a.u. represents arbitrary units. ns indicates not statistically significant. Error bars are s.e.m.