Kerstetter R, Vollbrecht E, Lowe B, Veit B, Yamaguchi J, Hake S
Department of Plant Biology, University of California, Berkeley 94720.
Plant Cell. 1994 Dec;6(12):1877-87. doi: 10.1105/tpc.6.12.1877.
The homeobox of the knotted1 (kn1) gene was used to isolate 12 related sequences in maize. The homeodomains encoded by the kn1-like genes are very similar, ranging from 55 to 89% amino acid identity. Differences outside the precisely conserved third helix allowed us to group the genes into two classes. The homeodomains of the seven class 1 genes share 73 to 89% identical residues with kn1. The four class 2 genes share 55 to 58% identical residues with kn1, although the conservation within the class is greater than 87%. Expression patterns were analyzed by RNA gel blot analysis. Class 1 genes were highly expressed in meristem-enriched tissues, such as the vegetative meristem and ear primordia. Expression was not detectable in leaves. The class 2 genes were expressed in all tissues, although one was abundantly expressed in roots. The genes were mapped using recombinant inbred populations. We determined that clusters of two to three linked genes are present on chromosomes 1 and 8; otherwise, the genes are distributed throughout the genome. Four pairs of genes, similar in both sequence and expression patterns, mapped within duplicated regions of the genome.
利用玉米中knotted1（kn1）基因的同源异型框分离出了12个相关序列。kn1类基因编码的同源异型结构域非常相似，氨基酸同一性在55%至89%之间。精确保守的第三螺旋之外的差异使我们能够将这些基因分为两类。7个1类基因的同源异型结构域与kn1的相同残基有73%至89%的一致性。4个2类基因与kn1的相同残基有55%至58%的一致性，尽管该类基因内部的保守性大于87%。通过RNA凝胶印迹分析对表达模式进行了分析。1类基因在富含分生组织的组织中高度表达，如营养分生组织和雌穗原基。在叶片中未检测到表达。2类基因在所有组织中均有表达，尽管其中一个在根中大量表达。利用重组自交群体对这些基因进行了定位。我们确定在第1号和第8号染色体上存在两到三个连锁基因的簇；否则，这些基因分布在整个基因组中。四对在序列和表达模式上都相似的基因，定位在基因组的重复区域内。
