转座元件是一类广泛分布于真核生物的可移动的遗传因子,可以引起基因重组和变异,在物种进化及遗传改良中起着重要作用。针对近年来原生动物全基因组序列中大量发现的转座元件,文章着重比较了转座元件在锥虫、利什曼虫、微孢子虫、变形虫和滴虫基因组序列中的存在种类、分布特征及其功能意义。原生动物转座元件以LINE和SINE为主,其次是DNA转座元件和LTR反转座元件,部分转座元件在高A+T含量区富集,预示着转座元件与基因组序列A+T含量有着紧密联系。根据不同种微孢子虫基因组之间转座元件的差异,推测在微孢子虫基因组进化过程中,至少经历了一次转座元件的丢失事件。最后对转座元件在原生动物寄生虫的进一步研究和应用作了展望。
Transposable elements are important factors to cause genetic variation and recombination, which are widely spreaded in eukaryotic organisms. Object to the increasing numbers of transposable elements in protozoa genome, this review focus on the types and genomic distributions of transposable elements in newly completed genome of protozoa parasite, mainly including Trypanosoma, Leishmania, microsporidia, Amoebozoa. The LINE and SINE elements are predominated in protozoa genome, followed by the DNA transposons and LTR retrotransposons. Several elements incline to insert in AT-rich region, suggesting the possible close relationship between the activity of transposable elements and AT content of genome. By the comparision of the divergence of transposable elements in microspordian genome, it was hypothesed that at least one loss event of transposable element had occurred during microsporidian genomic evolution. Finally, the prospects of transposable elements were discussed in the application of functional gene research of protozoa.