Analysis of Two Genes Expressed in Prepatterns in the Shoot Apex of Arabidopsis

施普林格9712927利用含有报告基因的DS转座子元件建立了一个转座子标签系统。已经产生了一个线集合，每个线包含一个随机插入到拟南芥基因组中的ds元素。Ds元件携带一个报告基因，允许通过报告基因监测附近基因的表达模式。对这些品系进行了拟南芥幼苗顶端报告基因的筛选。已经鉴定了几个基因，它们在茎顶端的离散区域中特异表达。这些基因包括在顶端分生组织中特异表达的基因，以及在每个叶原基底部区域中表达的基因。选择了两个品系(GT185和GT522)进行进一步鉴定。这两个品系都表现出报告基因在每个器官(莲座叶、茎生叶、花)和器官原基的一组细胞中的表达。这种表达模式表明，控制报告基因的基因可能参与了地上部顶端分生组织和器官原基之间的边界的建立。作为鉴定这两个品系中控制报告基因表达的基因的第一步，将仔细分析报告基因在不同发育阶段的表达模式。控制报告基因表达的基因将通过扩增DS插入两侧的DNA来克隆。这些基因将通过测序和原位杂交进行分子特征分析。GT185、GT522和两个基因之间的关系将被研究，这两个基因之前已经被证明在分生组织功能中发挥作用。

Springer 9712927 A transposon tagging system has been established using Ds transposable elements containing reporter genes. A collection of lines, each containing a Ds element inserted randomly in the Arabidopsis genome, has been generated. The Ds element carries a reporter gene, allowing the expression pattern of nearby genes to be monitored via the reporter gene. These lines have been screened for reporter gene expression in the shoot apex of Arabidopsis seedlings. Several genes have been identified that are specifically expressed in discrete domains within the shoot apex. These include genes expressed specifically in the shoot apical meristem, and genes expressed in domains at the base of each leaf primordium. Two lines (GT185 and GT522) have been chosen for further characterization. These lines both exhibit expression of the reporter gene in a group of cells subtending each organ (rosette leaf, cauline leaf, flower) and organ primordium. The expression pattern suggests that the genes controlling the reporter gene may be involved in the establishment of a boundary between the shoot apical meristem and organ primordia. As a first step in the characterization of the genes controlling reporter gene expression in these two lines, the reporter gene expression pattern will be carefully analyzed at different developmental stages. The genes controlling reporter gene expression will be cloned by amplification of DNA flanking the Ds insertion. The genes will be molecularly characterized by sequencing and in-situ hybridization. The relationship between GT185, GT522 and two genes that have previously been shown to play a role in meristem function will be examined.