Light-controlled production of spawning-inducing substance in jellyfish ovary
Light-controlled production of spawning-inducing substance in jellyfish ovary
复制标题
水母卵巢中产卵诱导物质的光控产生
作者：
S. Ikegami;N. Honji;M. Yoshida
水母 Spirocodon saltatrix 是水母科的一种钟形成员，直径在 5 至 8 厘米之间，在夜幕降临后不久产卵。将动物置于黑暗中会在大约 2 小时内导致成熟配子的大量释放，无论昼夜关系如何1-3。早上和下午早些时候从卵巢取出的卵母细胞未成熟，含有生发囊泡，而产卵总是完全成熟4。当与动物分离时，卵巢在1-2小时后在光照下排出卵子，并且卵巢内剩余的卵母细胞很小5。当这些卵巢置于光照下（水面约 8,000 Ix）时，它们的尺寸逐渐增大，15 小时后完全生长。我们在此报道，孤立的卵巢在黑暗中暴露 30 分钟后 50-70 分钟排出卵，在此期间卵巢中会产生低分子量的产卵诱导物质。卵巢在持续光照下无法产生这种物质。
THE jellyfish Spirocodon saltatrix, a bell-shaped member of the hydromedusae between 5 and 8 cm in diameter, spawns soon after nightfall; placing the animal in the dark causes a copious release of mature gametes within approximately 2 h, regardless of the day–night relationship1–3. Oocytes taken from the ovaries during the morning and early afternoon are immature and contain germinal vesicles whereas spawned eggs are always fully mature4. When isolated from the animals, the ovaries discharge eggs in the light 1–2 h later and the remaining oocytes inside the ovaries are small5. When these ovaries are placed in the light (about 8,000 Ix at the surface of the water) they gradually increase in size, becoming fully grown after 15 h. We report here that the isolated ovaries discharge eggs 50–70 min after a 30-min exposure to the dark, during which period a spawning-inducing substance of low molecular weight is produced in the ovaries. The ovaries fail to produce this substance in continuous illumination.