RUI: Molecular and Morphological Phylogenetic Systematics of Extant and Fossil Characeae (Charophyta)

9407606麦考特在分子和形态数据在一个系统发育问题上的有趣和具有挑战性的应用中，德保罗大学的理查德·麦考特教授将研究被称为石藻的藻类群，轮藻。该群体中所有七个属的活着成员的代表将通过核苷酸测序方法对一些基因进行分析，以获得物种之间突变差异的数据。这些相同分类群的形态特征，以及与法国古植物学同事合作获得的这些藻类化石形式的丰富记录的数据，将与DNA结果结合起来，重建轮藻的系统发育关系。轮藻对于藻类来说相对较大和复杂；它们在枝条的顶端有生长区和有鞭毛的精子细胞，与某些陆地植物的精子细胞比其他绿藻更相似。轮藻是与陆地植物在系统发育上最接近的藻类之一，轮藻很可能表现出进化适应，这将有助于了解陆地植物起源的变化序列。此外，他们的化石记录也为校准基因的分子变化率提供了机会。

9407606 McCourt In an intriguing and challenging application of both molecular and morphological data to a problem in phylogeny, Professor Richard McCourt at DePaul University will be studying the algal group known as stoneworts, the Charophyta. Representatives of all seven genera of living members of the group will be analyzed for a number of genes by nucleotide sequencing methods, to acquire data on mutational differences among the species. Morphological features of these same taxa along with data on the rich record of fossil forms of these algae, acquired in collaboration with French paleobotanical colleagues, will be integrated with the DNA results to reconstruct the phylogenetic relationships of the charophytes. The charophytes are relatively large and complex for algae; they have growing regions at the apex of branches and flagellated sperm cells that are more similar to those of certain land plants than to other green algae. As one of the algal groups closest phylogenetically to the land plants, the charophytes are likely to show evolutionary adaptations that will help understand the sequence of changes in the origin of land plants. As well, their fossil record provides an opportunity to calibrate rates of molecular change in genes.