Vieira Cristina, Biémont Christian
Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université Lyon 1, 69622 Villeurbanne Cedex, France.
Genetica. 2004 Mar;120(1-3):115-23. doi: 10.1023/b:gene.0000017635.34955.b5.
Transposable elements (TEs) in the two sibling species, Drosophila melanogaster and D. simulans, differ considerably in amount and dynamics, with D. simulans having a smaller amount of TEs than D. melanogaster. Several hypotheses have been proposed to explain these differences, based on the evolutionary history of the two species, and claim differences either in the effective size of the population or in genome characteristics. Recent data suggest, however, that the higher amount of TEs in D. melanogaster could be associated with the worldwide invasion of D. melanogaster a long time ago while D. simulans is still under the process of such geographical spread. Stresses due to new environmental conditions and crosses between migrating populations could explain the mobilization of TEs while the flies colonize. Colonization and TE mobilization may be strong evolutionary forces that have shaped and are still shaping the eukaryote genomes.
在两个亲缘关系相近的物种——黑腹果蝇和拟暗果蝇中，转座元件（TEs）在数量和动态变化方面存在显著差异，拟暗果蝇的转座元件数量比黑腹果蝇少。基于这两个物种的进化历史，已经提出了几种假说来解释这些差异，这些假说认为差异存在于种群的有效大小或基因组特征方面。然而，最近的数据表明，黑腹果蝇中转座元件数量较多可能与很久以前它在全球范围内的入侵有关，而拟暗果蝇仍处于这种地理扩散的过程中。当果蝇进行殖民化时，新环境条件和迁移种群之间的杂交所带来的压力可以解释转座元件的动员。殖民化和转座元件的动员可能是塑造并仍在塑造真核生物基因组的强大进化力量。
