转座子是一类散布在基因组中序列重复的DNA片段，它们可以通过特定转座酶在基因组中移动。目前测序的真核生物基因组的结果都显示转座子占基因组中相当大的一部分。目前对于转座子功能的研究主要集中在产生新功能、修饰染色质、保护生殖细胞，以及参与基因组的协同进化上。随着对其功能研究的深入，利用转座子转座能力开发的转基因系统可以改造物种的遗传性状。此外转座子还可以作为一个标尺用以分析物种进化关系。

Transposable elements (TEs) are regarded as a kind of movable DNA sequence with multiple copy number in genome that can be transmitted by the help of specific transcriptase. TEs account for a large part of host genome in the maps of sequenced insect species. Many studies including new function, chromatin modification, mermline protection, and involvement with hosts' co-evolution are being carried out nowadays. Owing to the profound understanding of TEs, transposon-mediated transgenic techniques are available to manipulate insect genetically. Moreover, TEs can be applied as a scale to analyze the phylogenic relationship.