Ancestral polyploidy in seed plants and angiosperms

Whole-genome duplication (WGD), or polyploidy, followed by gene loss and diploidization has long been recognized as an important evolutionary force in animals, fungi and other organisms, especially plants. The success of angiosperms has been attributed, in part, to innovations associated with gene or whole-genome duplications, but evidence for proposed ancient genome duplications pre-dating the divergence of monocots and eudicots remains equivocal in analyses of conserved gene order. Here we use comprehensive phylogenomic analyses of sequenced plant genomes and more than 12.6 million new expressed-sequence-tag sequences from phylogenetically pivotal lineages to elucidate two groups of ancient gene duplications-one in the common ancestor of extant seed plants and the other in the common ancestor of extant angiosperms. Gene duplication events were intensely concentrated around 319 and 192 million years ago, implicating two WGDs in ancestral lineages shortly before the diversification of extant seed plants and extant angiosperms, respectively. Significantly, these ancestral WGDs resulted in the diversification of regulatory genes important to seed and flower development, suggesting that they were involved in major innovations that ultimately contributed to the rise and eventual dominance of seed plants and angiosperms.     

生物科学专业实验教学创新教育模式的构建

分析高等院校现行的实验教学教育模式，发现存在有无法实现创新教育宗旨的弊端，通过加强创新教育理念的树立，明确专业创新能力培养的内涵，进行适应培养创新人才需要的课程体系改革，调整教学内容，改革教学的方法，建立能力水平考核方式等教学实施。构建生物科学专业实验教学新模式，从而充分发挥高等院校的优势，全面提高大学生的创新素质。