Koch E A, Spitzer R H
Cell Tissue Res. 1982;224(2):315-33. doi: 10.1007/BF00216876.
Quantitative light- and electron-microscopic autoradiography was used to evaluate metabolic processes that occur during late developmental stages (10-14) of oogenesis in Drosophila melanogaster. Major differences in radiolabelling patterns were found after in vivo (10-45 min) uptake of [3H]-monosaccharides and [3H]-L-lysine. Several different methods of data analysis were required to facilitate interpretation of these patterns. [3H]-L-lysine produced extensive cytoplasmic labelling at all developmental stages. In addition, about 15% of alpha yolk spheres were intensely labelled at stage 10, reflecting the incorporation of radiolabelled vitellogenins synthesized during the incubation period. Subsequent stages showed low silver grain density over alpha yolk spheres until stage 14, when a burst of [3H]-L-lysine incorporation by most alpha spheres was observed, possibly indicative of a maturation process for embryogenesis. [3H]-D-glucose and [3H]-D-galactose (10 min, in vivo) both induced intense labelling of the beta yolk spheres in a manner suggesting in situ assembly beginning at early stage 13. Inasmuch as the polysaccharide of beta yolk spheres has the properties of glycogen (e.g., rosette structure digested by alpha-amylase) and the radiolabelled monosaccharides were introduced intra-abdominally, it is evident that transport systems as well as enzymes utilizing glucose and galactose for glycogenesis must be readily available. It is notable that wide-spread labelling of egg chambers was elicited by [3H]-D-glucose and [3H]-D-galactose (e.g., nurse cells, follicle cells, chorion, vitelline membrane), but the labelling induced by [3H]-N-acetylmannosamine was restricted mainly to the endochorion. A possible role of microtubules in distribution and assembly of yolk spheres was inferred when colchicine, admixed to the culture medium (2-5 ppm), produced abnormal distribution and diminution in number of both alpha and beta yolk spheres. In addition to revealing previously unknown metabolic events of vitellogenesis, the results provide additional criteria for stage characterization as well as a means to specifically label certain macromolecules for purposes of isolation.
采用定量光镜和电镜放射自显影技术，对黑腹果蝇卵子发生后期发育阶段（10-14期）发生的代谢过程进行评估。在体内摄取[3H]-单糖和[3H]-L-赖氨酸（10-45分钟）后，发现放射性标记模式存在主要差异。需要几种不同的数据分析方法来辅助解读这些模式。[3H]-L-赖氨酸在所有发育阶段均产生广泛的细胞质标记。此外，在第10阶段，约15%的α卵黄球被强烈标记，这反映了在潜伏期合成的放射性标记卵黄生成素的掺入。后续阶段显示α卵黄球上的银粒密度较低，直到第14阶段，此时观察到大多数α卵黄球大量掺入[3H]-L-赖氨酸，这可能表明胚胎发生的成熟过程。[3H]-D-葡萄糖和[3H]-D-半乳糖（体内10分钟）均以一种表明从13早期开始原位组装的方式诱导β卵黄球强烈标记。由于β卵黄球的多糖具有糖原的特性（例如，被α-淀粉酶消化的玫瑰花结结构），且放射性标记的单糖是经腹腔内引入的，很明显运输系统以及利用葡萄糖和半乳糖进行糖原合成的酶必须随时可用。值得注意的是，[3H]-D-葡萄糖和[3H]-D-半乳糖引发了卵室的广泛标记（例如，滋养细胞、卵泡细胞、卵壳、卵黄膜），但[3H]-N-乙酰甘露糖胺诱导的标记主要局限于内卵壳。当秋水仙碱混入培养基（2-5 ppm）中时，α和β卵黄球均出现分布异常和数量减少，据此推断微管在卵黄球的分布和组装中可能发挥作用。除了揭示卵黄生成过程中以前未知的代谢事件外，这些结果还为阶段特征描述提供了额外标准，以及一种为分离目的特异性标记某些大分子的方法。
