Zimmerman M P, Thomas F C, Thompson J E, Djerassi C, Streiner H, Evans E, Murphy P T
Department of Chemistry, Stanford University, California 94305.
Lipids. 1989 Mar;24(3):210-6. doi: 10.1007/BF02535236.
The sponge Pseudaxinyssa sp., unique in sterol and fatty acid composition, was cellularly dissected into fractions enriched in each of the major cell types present in the sponge: microbial symbionts (cyanobacteria), small sponge cells (pinacocytes and choanocytes), and large sponge cells (archeocytes and cyanophytes). Three phototrophic microbial symbionts were also isolated from the cell fractions and grown in culture. An unsymmetrical distribution of fatty acids and sterols was observed for the sponge cells: small cells contained larger quantities of long chain fatty acids (greater than C24) and smaller quantities of sterols than were present in the larger sponge cells. Moreover, the rare sterols 24-isopropylcholesterol predominated in the smaller sponge cells, whereas its 22-dehydro analog predominated in the larger sponge cells. Long chain fatty acids and sterols were not detected in the cultured microbial symbionts. This constitutes the first report of lipid variability according to cell type for this most primitive group of Metazoa.
海绵 Pseudaxinyssa sp. 在甾醇和脂肪酸组成方面独具特色，通过细胞解剖将其分离为富含海绵体中每种主要细胞类型的组分：微生物共生体（蓝细菌）、小型海绵细胞（扁平细胞和领细胞）以及大型海绵细胞（原始细胞和蓝藻细胞）。还从细胞组分中分离出三种光合微生物共生体并进行培养。观察到海绵细胞中脂肪酸和甾醇的分布不对称：小型细胞含有比大型海绵细胞更多的长链脂肪酸（大于 C24）和更少的甾醇。此外，稀有甾醇 24 - 异丙基胆固醇在较小的海绵细胞中占主导，而其 22 - 脱氢类似物在较大的海绵细胞中占主导。在培养的微生物共生体中未检测到长链脂肪酸和甾醇。这是关于这种最原始的后生动物群体中脂质根据细胞类型变化的首次报道。
