GENETIC ANALYSIS OF MORPHOGENESIS IN A NEMATODE

尾部周围感觉器官的形态发生，称为射线， 梭雄性秀丽线虫将通过联合遗传学方法进行研究， 细胞和分子方法。 有九对双边的射线 在可重复的位置，在尾巴上形成一个物种特异性的图案。 的 理解这种模式生成的策略包括 三个步骤：1）定义决定性的细胞事件， 模式的产生，2）分离和研究突变体， 形态发生和调节基因以及 参与决定性的细胞事件，以及3）学习如何 形态发生和调节基因在形态发生途径中相互作用。 这项研究的长期目标是了解基因是如何指定 多细胞动物的形态。 射线发展的三个方面得到解决： 1. 光线的数量。 射线的数量由规格决定 一个表达射线亚系的细胞亚群。 亚谱系 产生两个神经元和一个支持细胞， 在最后的幼虫阶段。 为了理解 射线亚系的控制，遗传和分子分析的线性， 32基因是进入射线神经源性分支的关键基因 子系统，将被执行。 为了了解如何调节 射线亚谱系的表达在不同的细胞谱系中是不同的， mAb-19基因的类似分析，mAb-19基因是一种表达 射线亚谱系的相关细胞的子集，将进行。 初步分析了八种阻止射线发育的突变， 完成，特别强调确定细胞谱系 这些突变体中的缺陷 2. 光线差异的生成。 虽然他们是从一个刻板的 细胞亚系，9个双边对射线彼此不同 在形态学、超微结构、神经递质使用方面， 在发育过程中与邻近细胞的相互作用， 要求. 将进行激光烧蚀实验， 决定射线之间差异的细胞相互作用。 遗传 将对五个基因进行分子研究， 建立射线差异的野生型模式所需的。 3. 射线的特殊空间排列的形成。 遗传和 将对假设的基因进行分子表征， 在形态发生过程中参与射线细胞的相互作用， 它们在表皮内的正确位置。

The morphogenesis of peripheral sense organs, known as rays, in the tail of the C. elegans male will be studied by means of a combined genetic, cellular, and molecular approach. Nine bilateral pairs of rays are present at reproducible sites, forming a species-specific pattern in the tail. The strategy to be taken to understand the generation of this pattern comprises three steps: 1) Defining the determinative cellular events that govern generation of the pattern, 2) Isolating and studying mutants, identifying both the morphogenetic and regulatory genes and gene products that participate in determinative cellular events, and 3) Learning how morphogenetic and regulatory genes interact in a morphogenetic pathway. The long term goal of this research is to understand how genes specify the form of multicellular animals. Three aspects of ray development are addressed: 1. Number of rays. The number of rays is determined by the specification of a subset of cells that express the ray sublineage. The sublineage generates two neurons and a support cell, which differentiate into a ray during the last larval stage. In order to understand how initiation of the ray sublineage is controlled, a genetic and molecular analysis of the lin- 32 gene, a key gene for entry into the neurogenic branch of the ray sublineage, will be carried out. In order to learn how regulation of expression of the ray sublineage differs in different cell lineages, a similar analysis of the mab-19 gene, a gene required for expression of the ray sublineage by a subset of related cells, will be carried out. Preliminary analysis of eight mutations that block development of rays will be completed, with particular emphasis on determining the cell lineage defects, if any, in these mutants. 2. Generation of ray differences. Although they rise from a stereotyped cell sublineage, the nine bilateral pairs of rays differ from each other with respect to morphology, ultrastructure, neurotransmitter usage, interactions with neighboring cells during development, and genetic requirements. Laser ablation experiments will be carried out to define cellular interactions that determine differences between the rays. Genetic and molecular studies will be undertaken on five genes postulated to be required for establishing the wild type pattern of ray differences. 3. Formation of a specific spatial arrangement of rays. A genetic and molecular characterization will be carried out on the gene hypothesized to participate during morphogenesis in interactions of ray cells required for their correct positioning within the epidermis.