Vollbrecht E, Veit B, Sinha N, Hake S
USDA-ARS Plant Gene Expression Center, Albany, California 94710.
Nature. 1991 Mar 21;350(6315):241-3. doi: 10.1038/350241a0.
The Knotted-1 (Kn1) locus is defined by several dominant gain-of-function mutations that alter leaf development. Foci of cells along the lateral veins do not differentiate properly, but continue to divide, forming outpocketings or knots. The ligule, a fringe normally found at the junction of leaf blade and sheath, is often displaced and perpendicular to its normal position. The phenotype is manifested in all cell layers of the leaf blade, but is controlled by a subgroup of cells of the inner layer. Mutations result from the insertion of transposable elements or a tandem duplication. We show that the Kn1 gene encodes a homeodomain-containing protein, the first identified in the plant kingdom. Sequence comparisons strongly suggest that Kn1 acts as a transcription factor. Here we use the Kn1 homeobox to isolate other expressed homeobox genes in maize. The Kn1 homeobox may permit the isolation of genes that, like animal and fungal counterparts, regulate cell fate determination.
结瘤-1（Kn1）基因座由几个改变叶片发育的显性功能获得性突变所定义。沿着侧脉的细胞焦点不能正常分化，而是继续分裂，形成袋状或瘤状结构。叶舌，一种通常位于叶片和叶鞘交界处的边缘结构，常常移位并与其正常位置垂直。这种表型在叶片的所有细胞层中都有表现，但由内层的一个细胞亚群控制。突变是由转座元件的插入或串联重复引起的。我们发现Kn1基因编码一种含同源异型结构域的蛋白质，这是在植物界首次鉴定出来的。序列比较强烈表明Kn1作为一种转录因子发挥作用。在这里，我们利用Kn1同源异型框来分离玉米中其他表达的同源异型框基因。Kn1同源异型框可能有助于分离那些像动物和真菌中的对应基因一样调控细胞命运决定的基因。
