Swaminathan K, Yang Y, Grotz N, Campisi L, Jack T
Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755, USA.
Plant Physiol. 2000 Dec;124(4):1658-67. doi: 10.1104/pp.124.4.1658.
In yeast and animals, cyclins have been demonstrated to be important regulators of cell cycle progression. In recent years, a large number of A-, B-, and D-class cyclins have been isolated from a variety of plant species. One class of cyclins, the D-class cyclins, is important for progression through G1 phase of the cell cycle. In Arabidopsis, four D-class cyclins have been isolated and characterized (CYCLIN-D1;1, CYCLIN-D2;1, CYCLIN-D3;1, and CYCLIN-D4;1). In this report we describe the characterization of a fifth D-class cyclin gene, CYCLIN-D3;2 (CYCD3;2), from Arabidopsis. An enhancer trap line, line 5580, contains a T-DNA insertion in CYCD3;2. Enhancer trap line 5580 exhibits expression in young vegetative and floral primordia. In line 5580, T-DNA is inserted in the first exon of the CYCD3;2 gene; in homozygous 5580 plants CYCD3;2 RNA is not detectable. Even though CYCD3;2 gene function is eliminated, homozygous 5580 plants do not exhibit an obvious growth or developmental phenotype. Via in situ hybridization we demonstrate that CYCD3;2 RNA is expressed in developing vegetative and floral primordia. In addition, CYCD3;2 is also capable of rescuing a yeast strain that is deficient in G1 cyclin activity.
在酵母和动物中，细胞周期蛋白已被证明是细胞周期进程的重要调节因子。近年来，从多种植物物种中分离出了大量A类、B类和D类细胞周期蛋白。其中一类细胞周期蛋白，即D类细胞周期蛋白，对于细胞周期G1期的进程很重要。在拟南芥中，已分离并鉴定了四种D类细胞周期蛋白（细胞周期蛋白D1;1、细胞周期蛋白D2;1、细胞周期蛋白D3;1和细胞周期蛋白D4;1）。在本报告中，我们描述了从拟南芥中鉴定出的第五个D类细胞周期蛋白基因，即细胞周期蛋白D3;2（CYCD3;2）。一个增强子捕获系，5580系，在CYCD3;2中含有一个T-DNA插入。增强子捕获系5580在幼嫩的营养组织和花原基中表达。在5580系中，T-DNA插入到CYCD3;2基因的第一个外显子中；在纯合的5580植株中检测不到CYCD3;2 RNA。尽管CYCD3;2基因功能被消除，但纯合的5580植株并未表现出明显的生长或发育表型。通过原位杂交，我们证明CYCD3;2 RNA在发育中的营养组织和花原基中表达。此外，CYCD3;2还能够拯救一个缺乏G1细胞周期蛋白活性的酵母菌株。
