Pattern Formation in Developing Bacterial Colonies

Shapirio博士之前的工作强化了细菌菌落作为具有特定发育历史的高度组织化、差异化结构的观点。对携带多种lac融合元件的大肠杆菌菌株的研究提出了有关菌落发育过程中模式形成的细胞和分子事件的详细问题。其中一些关于细胞分化模式的问题可以通过使用组织化学、免疫学和原位杂交技术对菌落结构进行更详细的显微镜分析来回答。多细胞控制系统组成部分的鉴定将通过标准的分子遗传学方法（转座子诱变、克隆和已知调控突变的测试）启动。通过含有显示基因表达、菌落发育和细胞分裂的新遗传模式的细菌的部门的出现，进一步确定目前不可预测的形态发生调节系统变化的材料已经成为可能。这些细菌表达的新表型可以用与正常菌落相同的方法来表征，并且可以通过DNA转移和克隆程序来检查它们遗传变化的性质。一旦所有这些研究开始提供更精确的菌落结构及其潜在的遗传控制的图像，就有可能开始研究当多细胞接种物中的许多细菌细胞组织起来经历一个有规律的发育序列时会发生什么。夏皮罗博士提供了一些证据，证明细菌的菌落发育在形态上表现出一些明显的时间变化。他提出，这可以作为一种模型来获取关于多细胞生物如何发育和分化的信息。他的工作在这个领域是独一无二的，可能会导致分化研究的强大模型的发展。

Previous work of Dr. Shapirio has reinforced the view of bacterial colonies as highly organized, differentiated structures with specific developmental histories. Work with E. coli strains carrying various lac fusion elements has raised detailed questions about the cellular and molecular events involved in pattern formation during colony development. Some of these questions pertaining to patterns of cellular differentiation can be answered by a more detailed microscopic analysis of colony structure using histochemical, immunological and in situ hybridization technologies. Identification of the components of multicellular control systems will be initiated by standard molecular genetic methods (transposon mutagenesis, cloning and testing of known regulatory mutations). Further material for identifying currently unpredictable changes in morphogenetic regulatory systems has become available through the appearance of sectors containing bacteria that display novel hereditary patterns of gene expression, colony development and cell division. The novel phenotypes expressed by these bacteria can be characterized by the same methods that will be applied to normal colonies, and the nature of the hereditary changes in them can be examined by DNA transfer and cloning procedures. Once all these studies have begun to provide a more precise picture of colony structure and its underlying genetic control, it will be possible to begin investigating what happens when many bacterial cells in a multicellular inoculum organize themselves to undergo a regular developmental sequence. %%% Dr. Shapiro has provided some evidence that colony development in bacteria shows some distinct temporal changes in morphology. He proposes that this can be used as a model to obtain information about how multicellular organisms develop and differentiate. His work is unique in this area and could lead to the development of powerful models for the study of differentiation.