Delavault Philippe, Thalouarn Patrick
Groupe de Physiologie et Pathologie Végétales, Faculté des Sciences et des Techniques, BP 92208, 2 rue de la Houssinière, 44322 Cedex 3, Nantes, France.
Gene. 2002 Sep 4;297(1-2):85-92. doi: 10.1016/s0378-1119(02)00868-5.
Orobanche species characterization using plastid sequences as molecular markers revealed that O. cumana contains at least two distinct rbcL sequences: one similar in size to the truncated rbcL pseudogene from O. cernua, a closely related species, and another with a size comparable to that of rbcL plastid genes from autotrophic plants. In this work, the nucleotide sequences of these two copies are reported and analysed. The organization of the O. cumana plastid genome was investigated using a long-distance PCR strategy in order to determine their localization. Because of the non-plastid localization of the rbcL larger copy, Southern blot and PCR chromosome-walking experiments were carried out to better characterize this transferred sequence and to identify its localization. Then the mode of multiple transfer of genetic information from plastid to nucleus and the concomitant plastid sequence disorganization and migration during parasitic plant evolution are discussed.
利用质体序列作为分子标记对列当属植物进行表征，结果显示，向日葵列当至少包含两种不同的rbcL序列：一种大小与来自近缘物种弯管列当的截短rbcL假基因相似，另一种大小与自养植物的质体rbcL基因相当。在本研究中，报告并分析了这两个拷贝的核苷酸序列。为了确定它们的定位，采用长距离PCR策略研究了向日葵列当质体基因组的组织。由于rbcL较大拷贝的非质体定位，进行了Southern杂交和PCR染色体步移实验，以更好地表征该转移序列并确定其定位。随后讨论了在寄生植物进化过程中遗传信息从质体向细胞核多次转移的模式以及伴随的质体序列紊乱和迁移。
