ABSTRACT
Lycophytes and seed plants constitute the typical vascular plants. Lycophytes have been thought to have no paleo-polyploidization although the event is known to be critical for the fast expansion of seed plants. Here, genomic analyses including the homologous gene dot plot analysis detected multiple paleo-polyploidization events, with one occurring approximately 13-15 million years ago (MYA) and another about 125-142 MYA, during the evolution of the genome of Selaginella moellendorffii, a model lycophyte. In addition, comparative analysis of reconstructed ancestral genomes of lycophytes and angiosperms suggested that lycophytes were affected by more paleo-polyploidization events than seed plants. Results from the present genomic analyses indicate that paleo-polyploidization has contributed to the successful establishment of both lineages-lycophytes and seed plants-of vascular plants.
Subject(s)
Evolution, Molecular , Genome, Plant , Genomics , Phylogeny , Polyploidy , Selaginellaceae/geneticsABSTRACT
Purpose:To study the effect of radiotherapy combined with chemotherapy on advanced esophageal cancer. Methods:124 cases of advanced esophageal cancer were treated from March 1990 to April 1995. Patients were divided into 2 groups, including simple irradiation group receiving conventional radiotherapy to a total of 65～70 Gy; combined group which received the same radiotherapy as simple irradiation group plus chemotherapy with DFP or DF regimen. Both groups were followed for 5 years. Results:The short term results of radiotherapy combined with chemotherapy was better than that of radiotherapy alone. The difference between these two groups was statistically significant (P