| Summary: | 碩士 === 國立中興大學 === 昆蟲學系所 === 102 === ABSTRACT
The insecticidal effect of organophosphate and carbamate neurotoxic insecticides is mainly because of the inhibition of acetylcholinesterase (AChE) activity by chemicals, and thus disrupts the normal nerve conduction in insects. In recent years, food safety becomes the most concerned issue; and the pesticide residues on various agricultural products are strictly confined under safe ranges. Characteristics of the interaction of AChE and pesticides are considered that it could be used as potential biological tool for detecting pesticide residues on crops. In this study, therefore, an attempt to establish a detection method was conducted by targeting on the AChE of the oriental fruit fly, Bactrocera dorsalis (Hendel). Firstly, various amounts of the head homogenate of B dorsalis were reacted with acetylthiocholine iodide (a synthetic ACh compound) to establish appropriate detection ranges and standard methods. After several replicates of the reaction tests, the first six minutes was determined as an optimal light absorption observing time period. Furthermore, RT-PCR and molecular cloning technology were applied to isolate the cDNA fragments of full length and mature AChE proteins, respectively, to recombine the individual cDNA fragment into the pET 29a expression vector, and to transform the expression host E. coli (BL21). The current results showed that both full length and mature AChE proteins were not able to be expressed in the system. The possible reasons to lead these results may be due to that the AChE gene contains rare eukaryotic codons which are not able to be expressed in the prokaryotic host. However, the details have yet to be further investigated.
|
|---|
