Unuma T, Suzuki T, Kurokawa T, Yamamoto T, Akiyama T
Biol Bull. 1998 Feb;194(1):92-97. doi: 10.2307/1542517.
Female sea urchins store the major yolk protein (MYP) in ovarian nutritive phagocytes before vitellogenesis. Using immunological procedures, we detected MYP in the testicular nutritive phagocytes of Pseudocentrotus depressus, the red sea urchin, and then compared the distribution of MYP between sexes during gametogenesis. MYP was purified from unfertilized eggs by ion exchange chromatography (Q Sepharose) and gel filtration (Superdex 200), and an antiserum (anti-MYP) was raised against MYP. Immunoblot analysis demonstrated that immature testes, as well as ovaries, contained a large quantity of MYP. Immunohistochemistry showed that MYP was distributed in the nutritive phagocytes occupying the follicular lumen in both males and females. In both sexes, as gametogenesis proceeded, the nutritive phagocytes degenerated and the gonadal lumen filled with gametes. MYP accumulated in ripe ova as a yolk protein in the mature ovary. In contrast, MYP was not detected in mature testes, because stored spermatozoa did not react with anti-MYP. We conclude that in male P. depressus, MYP is stored in the testicular nutritive phagocytes and utilized as the nutrient source for spermatogenesis.
雌性海胆在卵黄发生之前，会将主要卵黄蛋白（MYP）储存在卵巢的营养吞噬细胞中。我们采用免疫学方法，在红海胆（Pseudocentrotus depressus）的睾丸营养吞噬细胞中检测到了MYP，然后比较了配子发生过程中MYP在两性之间的分布情况。通过离子交换色谱法（Q Sepharose）和凝胶过滤法（Superdex 200）从未受精卵中纯化出MYP，并制备了针对MYP的抗血清（抗-MYP）。免疫印迹分析表明，未成熟的睾丸以及卵巢中都含有大量的MYP。免疫组织化学显示，MYP分布于占据两性滤泡腔的营养吞噬细胞中。在两性中，随着配子发生的进行，营养吞噬细胞退化，性腺腔中充满了配子。在成熟卵巢中，MYP作为卵黄蛋白积累在成熟卵子中。相比之下，在成熟睾丸中未检测到MYP，因为储存的精子不与抗-MYP发生反应。我们得出结论，在雄性P. depressus中，MYP储存在睾丸营养吞噬细胞中，并作为精子发生的营养来源被利用。
