Kishimoto A, Nakato H, Izumi S, Tomino S
Department of Biology, Tokyo Metropolitan University, Japan.
Cell Tissue Res. 1999 Aug;297(2):329-35. doi: 10.1007/s004410051361.
Plasma proteins termed "SP1" and "30K proteins" are synthesized by the fat body cells of the silkworm, Bombyx mori, in a sex- and stage-specific manner during larval development. We successfully established a primary culture of the fat body cells in order to investigate the regulatory mechanisms of plasma protein gene expression. The primary cultures of fat body cells contained at least two cell types: small oval cells, and large spherical cells. The cells adhered to and migrated on the cultured dish after plating. By the 7th day of cultivation, the cells clustered to form fat body-like structures, which were maintained for at least 3 months. Plasma proteins were actively synthesized in the primary cultures of the fat body cells isolated from the final instar larvae only when the cells tightly adhered to and clustered on the cultured dish. Immunocytochemical analysis revealed that only 10-15% of the clustered cells synthesized plasma proteins in our culture system, indicating that the primary culture comprises heterogeneous cells that are morphologically and functionally distinct. The patterns of SP1 syntheses in primary cultures faithfully reproduced their sex-dependency in vivo.
血浆蛋白“SP1”和“30K蛋白”由家蚕（Bombyx mori）的脂肪体细胞在幼虫发育过程中以性别和阶段特异性方式合成。为了研究血浆蛋白基因表达的调控机制，我们成功建立了脂肪体细胞的原代培养体系。脂肪体细胞的原代培养物至少包含两种细胞类型：小椭圆形细胞和大球形细胞。接种后，细胞附着在培养皿上并迁移。培养至第7天时，细胞聚集形成脂肪体样结构，该结构至少维持了3个月。只有当从末龄幼虫分离的脂肪体细胞紧密附着并聚集在培养皿上时，血浆蛋白才会在脂肪体细胞的原代培养物中被积极合成。免疫细胞化学分析表明，在我们的培养体系中，只有10% - 15%的聚集细胞合成血浆蛋白，这表明原代培养包含形态和功能不同的异质细胞。原代培养中SP1的合成模式忠实地再现了其在体内的性别依赖性。
