Sieburth L E, Running M P, Meyerowitz E M
Department of Biology, California Institute of Technology, Pasadena 91125, USA.
Plant Cell. 1995 Aug;7(8):1249-58. doi: 10.1105/tpc.7.8.1249.
AGAMOUS (AG) is an Arabidopsis MADS box gene required for normal development of the third and fourth whorls of the flower. In previously described ag mutants, the third whorl stamens are replaced by petals, and the fourth whorl is replaced by another (mutant) flower. We describe two new ag alleles, ag-4 and AG-Met205, retaining partial AG activity. Both produce flowers with stamens in the third whorl and indeterminate floral meristems; however, ag-4 flowers contain sepals in the fourth whorl, and AG-Met205 produces carpels. The ag-4 mutation results in partial loss of the C terminus of the K domain, a putative coiled coil, and AG-Met205 contains a site-directed mutation that causes a single amino acid change in this same region of the K box. Two models that might explain how these changes in AG result in the separation of different AG activities are discussed.
AGAMOUS（AG）是一种拟南芥MADS盒基因，是花的第三和第四轮正常发育所必需的。在先前描述的ag突变体中，第三轮雄蕊被花瓣取代，第四轮被另一个（突变）花取代。我们描述了两个新的ag等位基因，ag-4和AG-Met205，它们保留了部分AG活性。两者都产生第三轮有雄蕊和不确定花分生组织的花；然而，ag-4花的第四轮含有萼片，而AG-Met205产生心皮。ag-4突变导致K结构域C末端部分缺失，K结构域是一个假定的卷曲螺旋，而AG-Met205包含一个定点突变，该突变在K盒的同一区域引起单个氨基酸变化。讨论了两种可能解释AG中的这些变化如何导致不同AG活性分离的模型。
