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Description:
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The development of genetic transformation systems in insects has revolutionized the field of entomology . Transgenic insects provide tools to identify , isolate and analyze insect genes and to genetically modify insects for the purposes of insect control or disease vector modification . When transformation frequencies are high , multiple transgenic lines can be generated with relative ease . However , in most mosquito species , the results of transformation experiments have been suboptimal . Increased mosquito transformation efficiency is a research priority . Additionally , incorporation of refractory transgenes will not be sufficient to modify natural populations . A gene drive system will be required to allow transgenes to proliferate throughout populations and potentially reach fixation . This study proposes the use of germline -specific regulatory elements to promote confined , regulated transposase expression within the germ tissue . Creation of helper constructs utilizing endogenous promoters will potentially increase genetic transformation frequencies . The generation of lab strains of mosquitoes expressing an endogenous source of transposase within the germline will also serve as a powerful research tool . Endogenous sources of transposase will allow for comparative analysis of integration rates using different donor plasmids . Finally , the generation of autonomous transposable elements will provide a gene drive mechanism to move a tightly -linked refractory gene into a population . Four genes have been identified , cloned , and characterized , revealing expression patterns expected of germline -specific genes . Transcription profiles and in situ hybridization data support these conclusions . Putative cis -acting regulatory elements have been cloned and incorporated into DNA plasmid constructs . These elements are cloned in a manner such that they will regulate fluorescent gene expression . Additionally , similar elements have been cloned upstream of the Mos1 open reading frame , within the inverted terminal repeats of the mariner transposable element , thus creating autonomous elements and a potential gene drive mechanism . |