Ohno Carolyn K, Reddy G Venugopala, Heisler Marcus G B, Meyerowitz Elliot M
Division of Biology 156-29, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA.
Development. 2004 Mar;131(5):1111-22. doi: 10.1242/dev.00991.
Important goals in understanding leaf development are to identify genes involved in pattern specification, and also genes that translate this information into cell types and tissue structure. Loss-of-function mutations at the JAGGED (JAG) locus result in Arabidopsis plants with abnormally shaped lateral organs including serrated leaves, narrow floral organs, and petals that contain fewer but more elongate cells. jag mutations also suppress bract formation in leafy, apetala1 and apetala2 mutant backgrounds. The JAG gene was identified by map-based cloning to be a member of the zinc finger family of plant transcription factors and encodes a protein similar in structure to SUPERMAN with a single C(2)H(2)-type zinc finger, a proline-rich motif and a short leucine-rich repressor motif. JAG mRNA is localized to lateral organ primordia throughout the plant but is not found in the shoot apical meristem. Misexpression of JAG results in leaf fusion and the development of ectopic leaf-like outgrowth from both vegetative and floral tissues. Thus, JAG is necessary for proper lateral organ shape and is sufficient to induce the proliferation of lateral organ tissue.
理解叶片发育的重要目标是鉴定参与模式形成的基因，以及将这些信息转化为细胞类型和组织结构的基因。锯齿状（JAG）位点的功能缺失突变导致拟南芥植株的侧生器官形状异常，包括锯齿状叶片、狭窄的花器官以及含有较少但更长细胞的花瓣。jag突变还会在多叶、无花瓣1和无花瓣2突变背景下抑制苞片形成。通过图位克隆鉴定出JAG基因是植物转录因子锌指家族的成员，编码一种结构与SUPERMAN相似的蛋白质，具有单个C(2)H(2)型锌指、富含脯氨酸的基序和短的富含亮氨酸的阻遏基序。JAG mRNA定位于整个植株的侧生器官原基，但在茎尖分生组织中未发现。JAG的错误表达导致叶片融合以及从营养组织和花组织中异位长出叶状结构。因此，JAG对于形成正常的侧生器官形状是必需的，并且足以诱导侧生器官组织的增殖。
