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Forensic Application of Mitochondrial DNA 16SrDNA Gene for Important Blowflies (Diptera: Calliphoridae) in China

Author: WangXingHua
Tutor: CaiJiFeng
School: Central South University
Course: Forensic
Keywords: Forensic entomology Mitochondrial DNA 16S Ribosomal DNA Calliphoridae Species Identification Postmortem Interval
CLC: D919.1
Type: Master's thesis
Year: 2011
Downloads: 28
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Abstract

Background: forensic entomology (Forensic entomology) is an application of entomological knowledge to solve legal problems especially in criminal cases, the detection of emerging disciplines, mainly for corruption corpse postmortem interval (Postmortem Interval, PMI) inferred. The main Sarcosaphagous insects including of Diptera flies in and Coleoptera beetles. Diptera Sarcosaphagous flies is the type of research and practical application, their growth and reproduction corruption corpse-eating special living habits often provide clues to homicide or John Doe case cracked. The body after death at different stages, to arrive different the corpse Sarcosaphagous flies species, showing a strong succession phenomenon. Necrophagous Calliphoridae (blow fly) is the first to appear in the body of flies, which Calliphoridae strongest sensitivity of bodies, often the first to reach the body, and lay eggs within a few hours after the death of the body, so , the determination the corpse flies Sarcosaphagous types and hair of childbearing age often is the estimated time after the death of key insect information (PMI). Most of the insects in the early and mid corpse in a non-mature stage, insect eggs and early larvae are morphologically very similar, therefore, more difficult to identify using traditional morphological methods. To solve this problem, this study used in recent years, the rapid development of molecular biology techniques, the use of self-16S rDNA primers designed from the gene level to explore the identification of insect species to provide basic information. Objective: This study based on literature reported data, their own design can obtain short segment 16SRibosomal of DNA (16S rDNA) sequences of primers, short segment 16SrDNA distinguish common addicted corpse sexual Korea flies, looking for common addicted corpse sexual Korea flies of molecular markers, for the use of The presumed dead necrophagous Calliphoridae time to provide technical support. Method: random collection of several regional outdoor multi-point the Flies sample placed on animal carcasses. Small insects DNA homogenate using improved method to extract the flies mtDNA detection of DNA purity and concentration of the protein and nucleic acid analyzer, Eppendorf5331 gradient PCR amplification; 7% polyacrylamide non-denaturing gel and discontinuous buffer system vertical electrophoresis and 0.8% detection of mitochondrial DNA and PCR products in agarose gel electrophoresis, PCR Gel Extraction Kit purification and PCR products were sequenced; the MEGA4 package sequence analysis and phylogenetic tree was constructed. Results: PCR amplification and DNA sequencing of the mitochondrial 16SrDNA gene to effectively detect gene sequences necrophagous Calliphoridae samples. By molecular evolutionary relationships to obtain samples kinship Figure 4 genera (bare gold Genus gold Genus Lucilia genus Calliphora genus), 10 kinds of flies (Lucilia, thus effectively identified, Pseudomonas fly, fork leaf green flies, light green flies, purple and green flies, the Nanling Lucilia megacephala of Fei Yan bare gold flies, red head blowflies regurgitant Calliphoridae) species relationships. Conclusion: mtDNA 16SrDNA 289bp gene sequence analysis is an effective tool to identify types of Calliphoridae. The detection method is rapid, simple and accurate, the new method can be used as forensic science to identify Sarcosaphagous types of flies, which provide the basis for the postmortem interval. 2 short segment 16SrDNA sequence there are certain limitations UPGMA phylogenetic tree, of Fei Yan bare gold fly alone into a bunch of separate genus and the same as gold flies megacephala species using molecular marker technology to identify flies just a supplement to traditional morphological methods. In different regions of the same kind of flies were not significant, further research need to increase the sample size of the same species in different regions.

Forensic Application of Mitochondrial DNA 16SrDNA Gene for Important Blowflies (Diptera: Calliphoridae) in China

Abstract

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