Walden A R, Walter C, Gardner R C
School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand.
Plant Physiol. 1999 Dec;121(4):1103-16. doi: 10.1104/pp.121.4.1103.
We describe the isolation and characterization of 13 cDNA clones that are differentially expressed in male cones of Pinus radiata (D. Don). The transcripts of the 13 genes are expressed at different times between meiosis and microspore mitosis, timing that corresponds to a burst in tapetal activity in the developing anthers. In situ hybridization showed that four of the genes are expressed in the tapetum, while a fifth is expressed in tetrads during a brief developmental window. Six of the seven cDNAs identified in database searches have striking similarity to genes expressed in angiosperm anthers. Seven cDNAs are homologs of defense and pathogen response genes. The cDNAs identified are predicted to encode a chalcone-synthase-like protein, a thaumatin-like protein, a serine hydrolase thought to be a putative regulator of programmed cell death, two lipid-transfer proteins, and two homologs of the anther-specific A9 genes from Brassica napus and Arabidopsis. Overall, our results support the hypothesis that many of the reproductive processes in the angiosperms and gymnosperms were inherited from a common ancestor.
我们描述了13个在辐射松（D. Don）雄球果中差异表达的cDNA克隆的分离和特性分析。这13个基因的转录本在减数分裂和小孢子有丝分裂之间的不同时间表达，其时间与发育中的花药绒毡层活性的爆发相对应。原位杂交显示，其中四个基因在绒毡层中表达，而第五个基因在一个短暂的发育窗口期间在四分体中表达。在数据库搜索中鉴定出的七个cDNA中有六个与被子植物花药中表达的基因有显著相似性。七个cDNA是防御和病原体反应基因的同源物。所鉴定的cDNA预计编码一种查尔酮合酶样蛋白、一种类甜蛋白、一种被认为是程序性细胞死亡假定调节因子的丝氨酸水解酶、两种脂质转移蛋白，以及来自甘蓝型油菜和拟南芥的花药特异性A9基因的两个同源物。总体而言，我们的结果支持这样一种假说，即被子植物和裸子植物的许多生殖过程是从一个共同祖先遗传而来的。
