Molecular evolution of ribosomal DNA and its transposons in Daphnia.

很大一部分动植物基因组由重复序列组成，这些重复序列影响基因表达模式、细胞分裂速度和细胞大小。这些重复的或多基因家族的成员在物种之间存在分歧，但通常在物种内是同质的，这被称为协同进化。这种同质性是通过重复单位之间的重组来维持的，重复单位的产物在种群水平上受到遗传漂移、基因流动和自然选择的影响。新的变异在一个基因家族和整个物种中传播的速度取决于重组的速度、基因家族的大小、基因家族出现的染色体数量和种群结构。我研究的长期目标是以水蚤的核糖体DNA为模型系统，了解多基因家族进化的机制和后果。

A large fraction of plant and animal genomes consists of repeated sequences that impact patterns of gene expression, rates of cell division and cell size. The members of these repeated, or multigene families diverge between species, but are generally homogeneous within species, which is known as concerted evolution. This homogeneity is maintained by recombination between repeat units, the products of which are subject to genetic drift, gene flow and natural selection at the population level. The rate at which new variants spread through a gene family, and an entire species depends on rates of recombination, gene family size, the number of chromosomes on which the gene family occurs and population structure. The long-term goal of my research is to understand the mechanisms and consequences of multigene family evolution using ribosomal DNA in the waterflea, Daphnia as a model system.