Figure 5.

Cyclin Dd levels in the germline are gradually reduced when growth arrest occurs in response to nutrient limitation. Oikopleura dioica were pulsed with the S-phase marker IdU for 1 h at day 3 when cultured under standard conditions or for 1 h at days 3, 6 and 12 when cultured under dense conditions. IdU incorporation and Cyclin Dd immunostaining were then assessed. Levels of Cyclin Dd during the early period of growth arrest remained similar to that observed under standard conditions but then gradually decreased as growth arrest persisted (n = 8 animals). Scale bars = 5 μm.