Dissertation > Biological Sciences > Entomology > Insect genetics

Molecular Systematic Study on Several Genera of Myrmicinae (Hymenoptera :Formicidae) from Guangxi

Author ChenZhenPeng
Tutor ZhouShanYi
School Guangxi Normal University
Course Ecology
Keywords Myrmicinae mtDNA CO1 gene CO2 gene tRNAleu gene Molecular phylogeny and evolution
CLC Q963
Type Master's thesis
Year 2004
Downloads 148
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Ants belonging to Hymenoptera (Hymenoptera), Formicidae (Myrmicinae), is typical of social insects, according to statistics, the world has documented a total of 16 extant ant subfamilies, 296 genera and 9538 kinds. Estimated that worldwide there are 15,000 species of ant species, they form a large population of animals in terrestrial ecosystems dominant position, and that reflects the high degree of social ant behavior, so that its research in evolutionary biology has a very important position. In this study, widely Xiqie leaves Formicinae insects as the research object, the application of DNA sequencing technology to obtain wide Xiqie leaf Formicinae seven genera and 12 species of mitochondrial cytochrome oxidase subunit 1 and 2, and complete a total length of about 851bp of the gene tRNAleu DNA sequences. Sequences of these genes, using MEGA, DNASP, Phylip and other software for data processing and analysis, molecular phylogenetic study on broad Xiqie leaf Formicinae seven genera and 12 species between the taxonomic status and relationship, revealing the leaf-cutting ants Asia Section 7 genera and 12 species phylogeny and evolutionary relationships. For the development of molecular systematics provide new information and academic point of view, enrich and improve Formicidae molecular phylogeny for the wide Xiqie insect leaf Formicinae basis for the study of molecular systems. In the obtained sequence of about 851bp of DNA, AT about 75.75%, GC about 24.25%, the overall AT bias characteristics clearly demonstrated, which is similar to other insects. From the point of view throughout the study, from the nucleotide sequence analysis of the basic components to the non-synonymous substitution and synonymous substitution studies, from nucleotide diversity among populations converted to partial correlation with transversion distance analysis and phylogenetic analysis of the final The results imply a higher rate of CO2 CO1 gene phylogenetic evolution rate. In various analyzes (including nucleotide base composition analysis; basic amino acid composition analysis; nucleotide diversity analysis; non-synonymous substitution and synonymous substitution analysis; codon usage analysis; conversion transversion analysis; tRNAleu gene Ring two four-arm structure analysis; \place. Through the various aspects of research and analysis to obtain evidence and information display, the final results of the analysis of molecular phylogeny: pavement ant genus with red ants are two small branches form a large branch; Pheidole genus and chest ribbed leaf-cutting ants belong to this two small branches form a large branch; giant ant genus and the first disc abdomen ant genus two small branches form a large branch; composed of the three major branches of a larger branch; rather give abdomen abdomen ant ant genus Tour held (C.vagula) in this large lateral branches. According to the evolution of the original order of the studied species are arranged as follows: the first giant ant genus gt; cite abdomen ant genus gt; edge chest leaf-cutting ant genus gt; pavement ant genus gt; Pheidole genus gt; red ant genus gt; ventral plate ant genus; Or may be: first giant ant genus ≥ cite abdomen ant genus gt; edge chest leaf-cutting ant genus gt; plate abdomen ant genus gt; pavement ant genus gt; Pheidole genus gt; red ant genus. Results from this study analysis can be seen, CO1 gene, CO2 genes and gene tRNAleu is suitable for evolutionary relationships among and phylogenetic analysis, rather unsuitable for the species in particular is very close genetic relationship between the evolution of species and phylogenetic analysis of research and study, and if the case involves more than just problems between research questions, but includes the species problem, which requires a more appropriate choice and are considering incorporating genes, such as cytochrome b gene (Cytb ), which is greater than the rate of gene evolution gene CO1 and CO2 evolution rate. These problems need to be in the future in-depth study. In this study, by analyzing the secondary structure of the gene tRNAleu get some meaningful information, which means that research and analysis from junior to senior structural development of the structure, to the exercise by the genetic structure of the function, the internal structure and mechanism of re- traits and characteristics to the surface, which will be the future development of molecular systematics another trend, as it was by the traditional phylogenetic analysis into microscopic and macroscopic molecular phylogeny generated with molecular studies the deepening and development of molecular phylogeny should be, but also from the microscopic to the macroscopic analysis of the direction of development, micro and macro, this should be made between the two are complementary and mutually reinforcing and mutually beneficial. In addition, from the research point of view, proper and reasonable sampling, get more information, including nucleotide sites, amino acid sites and through different means and methods of analysis, based on different theories, combining different evidence and results etc., which all contribute to better explore and solve problems, find and interpret its own rules, allowing researchers to develop a deeper level and to the wider spatial extension.

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