Fig. 3. Changes in I_Cl,swell at the G₂/M border. (A) Mean (±s.e.m.) currents in 2-cell stage embryos in late G₂ (2c late G₂), in prophase (2c proph), and in metaphase (2c meta), as determined by nuclear morphology (Fig. 2), and in 4-cell embryos 1 hour and 5-6 hours after cytokinesis, as indicated. Data for 1-cell embryos in metaphase (1c meta) are shown at right. Annotations are as in Fig. 1 (in addition, *P<0.05). The mean increase in diameter upon swelling was 16, 17 and 19% for late G₂, prophase, and metaphase 2-cell embryos respectively, 20 and 17% for 1 hour and 5-6 hours 4-cell embryos respectively, and 14% for 1-cell metaphase embryos. The inset shows currents for individual 2-cell embryos during late G₂, prophase, or metaphase, shown above the corresponding bars, with data obtained from the same embryo before swelling, after swelling, and then after introduction of DIDS connected. (B) Examples of currents in individual embryos in late G₂ of the 2-cell stage, and metaphase of the 1-cell and 2-cell stages (see Fig. 1 legend for description).