Rerie W G, Feldmann K A, Marks M D
School of Biological Sciences, University of Nebraska-Lincoln 68588-0118.
Genes Dev. 1994 Jun 15;8(12):1388-99. doi: 10.1101/gad.8.12.1388.
The GLABRA2 gene (GL2) is one of several genes known to have a role in trichome development in Arabidopsis. Mutations at this locus result in abnormal trichome expansion. We have identified several gl2 mutants from a T-DNA-mutagenized population of plants. The T-DNA insert in one of the mutant lines cosegregated with the recessive gl2 phenotype and thus served as a molecular tag to isolate genomic DNA at the putative GL2 locus. RFLP analysis of the segregating population and subsequent molecular complementation experiments established that the GL2 gene had been cloned. The predicted polypeptide from one of the ORFs contained on this fragment showed significant identity to the homeo domain sequence. The construction of a full-length cDNA by RT-PCR confirmed the presence of a homeo box in the GL2 gene and showed that it is substantially different from other recently cloned homeo box genes in plants. The expression pattern of GL2, as demonstrated by in situ hybridization, indicated that the gene is expressed in trichome progenitor cells and at stages associated with trichome development. This suggests that GL2 may regulate events required for the directional cell expansion observed during trichome formation.
GLABRA2基因（GL2）是已知在拟南芥毛状体发育中起作用的几个基因之一。该位点的突变导致毛状体异常扩展。我们从一个经T-DNA诱变的植物群体中鉴定出了几个gl2突变体。其中一个突变株系中的T-DNA插入与隐性gl2表型共分离，因此可作为分子标签用于在假定的GL2位点分离基因组DNA。对分离群体的RFLP分析及随后的分子互补实验证实已克隆到GL2基因。该片段上所含一个开放阅读框的预测多肽与同源异型结构域序列具有显著同源性。通过RT-PCR构建全长cDNA证实了GL2基因中存在一个同源异型框，且表明它与植物中最近克隆的其他同源异型框基因有很大不同。原位杂交显示的GL2表达模式表明，该基因在毛状体祖细胞以及与毛状体发育相关的阶段表达。这表明GL2可能调控毛状体形成过程中定向细胞扩展所需的事件。
