Oliveira de Carvalho M, Silva J C, Loreto E L S
Departamento de Biologia, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil.
Insect Mol Biol. 2004 Feb;13(1):55-63. doi: 10.1111/j.1365-2583.2004.00461.x.
We have identified 50 P element-homologous sequences in the genome of Anopheles gambiae by performing homology searches against the public genome database of A. gambiae using the canonical P element from Drosophila melanogaster as a query sequence. While most of these sequences belong to P subfamilies previously described from anopheline mosquitoes, at least four new subfamilies were identified. One of these A. gambiae P elements, which we termed AgPLS, was analysed in detail. AgPLS consists of three exons and does not have inverted terminal repeats. This element retains several of the structural features of other P-encoded peptides, such as motifs involved in DNA-protein and protein-protein interaction, and a motif involved in GTP utilization. Strong sequence and structural similarity to functional P elements, a number of nonsynonymous substitutions that is smaller than that of synonymous substitutions and the presence of putative nuclear localization signals suggest that the A. gambiae elements may retain the capacity for transposition or its repression. These sequences seem to be most closely related to P elements described from Musca domestica and Lucilia cuprina, the only P element hosts known outside the family Drosophilidae.
我们通过使用来自黑腹果蝇的典型P元件作为查询序列，对冈比亚按蚊的公共基因组数据库进行同源性搜索，在冈比亚按蚊的基因组中鉴定出了50个P元件同源序列。虽然这些序列中的大多数属于先前从按蚊中描述的P亚家族，但至少鉴定出了四个新的亚家族。我们对其中一个冈比亚按蚊P元件（我们称之为AgPLS）进行了详细分析。AgPLS由三个外显子组成，没有反向末端重复序列。该元件保留了其他P编码肽的几个结构特征，例如参与DNA-蛋白质和蛋白质-蛋白质相互作用的基序，以及参与GTP利用的基序。与功能性P元件的强序列和结构相似性、非同义替换数量小于同义替换数量以及推定的核定位信号的存在表明，冈比亚按蚊元件可能保留了转座或其抑制的能力。这些序列似乎与家蝇和铜绿蝇中描述的P元件关系最为密切，家蝇和铜绿蝇是果蝇科以外已知的仅有的P元件宿主。
