一个新的mariner类转座子的鉴定

Identif ication of a Novel mariner-like Transposable Element

根据mariner类转座子转座酶的保守区设计简并引物,以曲阜灰飞虱的基因组DNA为模板,通过PCR扩增、回收、克隆和测序,得到长为493bp的片段,命名为qfclone493,提交GenBank数据库,获得注册号为EU542024.将qfclone493与19种有代表性的mariner类转座子核苷酸序列进行系统学分析,结果表明qfclone493属于mauritiana亚族,与此亚族已知mariner类转座子的核苷酸序列同源性最高为74%,认为qfclone493是mauritiana亚族的一个新的mariner类转座子,命名为lsmar1.序列分析表明,lsmar1的最大ORF仅编码141个氨基酸,不能表达完整的转座酶;与隶属于同一亚族、且具有完全自主活性的mos1相比,lsmar1所编码的氨基酸序列在核定位信号(Nuclear location signal,NLS)和D,D(34)D关键部位发生突变,因此推测lsmar1可能不具有转座活性.

Total DNA of Laodelphax striatellus was extracted, and one DNA fragment was amplified by the degeneracy primers designed from conserved regions of transposase of the mariner-like transposable elements. The sequencing results showed that the length of the obtained fragment was 493 bp. It was named qfclone493 and given the accession No. of EU542024 from the GenBank. Phylogeny analysis on nucleotide sequence was performed among qfclone493 and 19 species of mariner-like transposable elements downloaded from the GenBank. The results indicated that qfclone493 copy belonged to the mauritiana subfamily. The highest homology of nucleotide sequence between qfclone493 and the other known members of mauritiana subfamily was 74%. qfclone493 was considered to be a new member of transponson of the mauritiana subfamily and designated tentatively as lsmar1. The results of sequence analysis revealed that the largest ORF of lsmar1 encoded only 141 amino acids, and could not encode the intact transposase. In addition, compared with the amino acids encoded by the mos1, there were mutations on the key regions of nuclear localization signal （Nuclear location signal, NLS） and the motif of the D,D（34）D triad of the amino acids encoded by the lsmar1. Therefore, it can be conjectured that the lsmar1 is an inactive mariner-like transposable element. Fig4, Ref23