为了探讨Tc1/Mariner转座子在4种鲇(沟鲇、黑斑原、鲇和南方鲇)中的特征及在演化过程中的作用，实验使用de novo预测和同源预测两种方法鉴定了4种鲇基因组中的Tc1/Mariner转座子并进行演化分析。通过对所获得序列的统计及分类，结果显示，4种鲇基因组中Tc1/Mariner转座子的含量分别为9.46%、2.70%、7.83%和8.54%，并且分别被分为38、20、43和55个家族。基于转座酶催化区域的结构和系统发育分析的结果，4种鲇的Tc1/Mariner转座子总共可以分为5个不同的亚类群：DD34E(Tc1)、DD35E、DD36E、DD37E和DD35D(pogo)。系统发育分析表明，多数支系中鲇和南方鲇的转座子聚为姐妹群。插入时间分析表明，Tc1/Mariner转座子的插入时间主要分布在0~5百万年前。大多数Tc1/Mariner转座子在0~1百万年前或2~3百万年前有一个突然的扩增。另外，4种鲇的Tc1/Mariner转座子大部分插入到基因的内含子中。本实验通过对4种鲇中Tc1/Mariner转座子的鉴定、比较与演化分析，为Tc1/Mariner转座子的深入研究奠定了基础。

To investigate the characteristics of Tc1/Mariner transposons in four catfish genomes (Ictalurus punctatus, Glyptosternum maculatum, Silurus asotus and S. meridionalis) and their role in the evolution, we used de novo and homology methods to predict Tc1/Mariner transposons and explored the role in the evolution of those four catfishes. The results showed that the contents of Tc1/Mariner transposons in the four catfishes were 9.46%, 2.70%, 7.83% and 8.54%, respectively. All the Tc1/Mariner transposons in the four catfishes were classified into 38, 20, 43 and 55 families, respectively. Based on the structural and phylogenetic analysis of the catalytic region of the transposase, the Tc1/Mariner transposons in the four catfishes can be classified into five different subgroups: Tc1 (DD34E), DD35E, DD36E, DD37E and pogo (DD35D). Phylogenetic analysis indicated that the transposons of most of the branches for S. asotus and S. meridionalis were clustered into sister groups. The results indicated that the insertion time of the majority Tc1/Mariner transposons mainly ranges between 0-5 Mya (million years ago). Many Tc1/Mariner transposons have a burst expansion between 0-1 Mya or 2-3 Mya. In addition, most of the Tc1/Mariner transposons in the four catfishes were inserted into the intron of the gene. In summary, this study provides new insights into the evolution of Tc1/Mariner transposons in the fish genomes.

Q785;S917.4

国家自然科学基金(31572254)