The Mitochondrial Genome of Aedes albopictus Skuse
| Autor: | HSiu-Ping Chang, 張秀萍 |
|---|---|
| Rok vydání: | 2002 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 90 Aedes albooictus (Skuse) is a mosquito which originally occurs in Asia. During this century this century, this mosquito has expanded into South and North America. It is associated with the transmission of dengue fever and Eastern equine encephalitis. Partial mitochondrial genes of Aedes albopictus were obtained by polymerase chain reaction (PCR) in this study. The nucleotide sequences were determined after transformation into the plasmid of E.Coli. Combination was made for the sequences derived in this study and those of reported previously by the colleagues in our laboratory. We obtained the entire mitochondrial genome of Aedes albopictus. The total length of the mitochondrial genome of this mosquito is found to be approximately 16,665bp. These genes were identified by comparing with the published sequences of Anopheles. In Aedes albopictus, the mitochondrial genome contains genes that encode 13 protein-coding genes, 22 transfer RNA, two ribosomal RNA and a control region. The arrangement and orientation of transcription and replication of these genes in Aedes albopictus are identical to those of Anopheles quadrimaculatus, Anopheles gambiae and Aede aegypti. The average nucleotide content of A and T is 79.4% in protein-coding genes. The high content of A and T is also reflected in the codon usages, especially at the third position. The nucleotide sequences between genes of the cytochromic oxidase complex (COI、COII、COIII) and cytochrome b reveal low variation among species in arthropods. However, genes for NADH dehydrogenase complex (ND1、ND2、ND3、ND4、ND4L、ND5、ND6) show greater variation. The 22 tRnA sequences indicate that the secondary structures are identical to those of those of Anopheles, except tRNASer. The length of the tRNA sequences ranges from 64 ~ 73 bp. Moreover, the nucleotide sequence of genes for 16S and 12S ribosomal RNA is also highly conserved because of the constrain in the secondary. In particular, the control region of mitochondrial DNA of Aedes albopictus is 1,772 bp in length, it is heavily biased to A and T nucleotide composed of 91.6%. Tandem repetition was observed in this region. Variation in size and copy number was also shown in this region as follows: type I contain5 copies of 186 ~ 191 bp / copy; Type II with 2 copies of 100 bp / copy and type III with 4 copies of 38 ~ 42 bp / copy. Tandem repetition of control region is not observed in Anopheles. Each of the mitochondrial genes was examined for Aedes albopictus and 11 species of arthropod in this study. The pairwise comparisons show that the sequences in mitochondrial genes are likely to be useful to address phylogenetices over different levels of divergence. The sequences of 12S rRNA, 16S rRNA and tRNA appear to best for arthropods from subfamily to class. The sequences of the highly conserved protein-coding genes could be useful to infer the relationships among genera to families. The sequences of the variable protein-coding genes may be used to infer the divergence among closely related species. Finally the control region can be a suitable marker for study genetic polymorphism and population structure in species. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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