Fig. 7. Synchronous recovery from acidosis in oocytes and accompanying granulosa cells. Cumulus oocyte complexes from the ovaries of PMSG-primed adult mice were carefully cleaned so as to produce denuded oocytes, and oocytes with a part-covering of granulosa cells. Following loading with SNARF-AM, both oocyte and granulosa cell regions are clearly visible, such that regions of interest (ROI) for analysis can be positioned to measure pH independently in the different compartments (see inset; ROI examples outlined in white). The graph shown is one of four independent replicates, which comprised 26 denuded and 30 part-enclosed oocytes in total. The average curve for each cell type is shown. Note that pH_i of part-enclosed oocytes closely reflects that of the accompanying granulosa cells, including a steady pH_i increase which occurs during the Na⁺-free period, which is not evident in denuded oocytes. Over the course of three experiments, 26 oocyte-granulosa complexes and 30 denuded oocytes were examined.