Carolina Concha, Ying Yan, Alex Arp, Evelin Quilarque, Agustin Sagel, Adalberto Pérez de León, W Owen McMillan, Steven Skoda, Maxwell J Scott
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引用次数: 15
Abstract
Background: The New World Screwworm fly (NWS), Cochliomyia hominivorax, is an ectoparasite of warm-blooded animals and a major pest of livestock in parts of South America and the Caribbean where it remains endemic. In North and Central America it was eradicated using the Sterile Insect Technique (SIT). A control program is managed cooperatively between the governments of the United States and Panama to prevent the northward spread of NWS from infested countries in South America. This is accomplished by maintaining a permanent barrier through the release of millions of sterile male and female flies in the border between Panama and Colombia. Our research team demonstrated the utility of biotechnology-enhanced approaches for SIT by developing a male-only strain of the NWS. The strain carried a single component tetracycline repressible female lethal system where females died at late larval/pupal stages. The control program can be further improved by removing females during embryonic development as larval diet costs are significant.
Results: The strains developed carry a two-component system consisting of the Lucilia sericata bottleneck gene promoter driving expression of the tTA gene and a tTA-regulated Lshid proapoptotic effector gene. Insertion of the sex-specifically spliced intron from the C. hominivorax transformer gene within the Lshid gene ensures that only females die when insects are reared in the absence of tetracycline. In several double homozygous two-component strains and in one "All-in-one" strain that had both components in a single construct, female lethality occurred at the embryonic and/or first instar larval stages when raised on diet without tetracycline. Laboratory evaluation for phenotypes that are relevant for mass rearing in a production facility revealed that most strains had fitness characteristics similar to the wild type J06 strain that is currently reared for release in the permanent barrier. Testing of an "All in one" strain under mass rearing conditions showed that the strain maintained the fitness characteristics observed in small-scale rearing.
Conclusions: The early female lethal strains described here could be selected by the NWS Control Program for testing at large scale in the production facility to enhance the efficiency of the NWS eradication program.
背景:新世界螺旋蝇(New World Screwworm fly, NWS)是温血动物的一种体外寄生虫,也是南美洲和加勒比部分地区牲畜的主要害虫。在北美和中美洲,使用昆虫不育技术(SIT)将其根除。控制方案是美国和巴拿马政府之间的合作管理,以防止NWS从南美侵染国家向北蔓延。这是通过在巴拿马和哥伦比亚之间的边界释放数百万只不育的雄性和雌性苍蝇来维持永久屏障来实现的。我们的研究小组通过开发NWS的雄性菌株,证明了生物技术增强方法对SIT的实用性。该菌株携带单组分四环素抑制雌虫致死系统,雌虫在幼虫/蛹后期死亡。由于幼虫的饮食成本很高,可以通过在胚胎发育期间去除雌性来进一步改善控制程序。结果:培养的菌株携带一个双组分系统,包括驱动tTA基因表达的丝光Lucilia sericata瓶颈基因启动子和tTA调控的Lshid促凋亡效应基因。在Lshid基因中插入来自C. hominivorax变形基因的性别特异性剪接内含子,确保在没有四环素的环境下饲养昆虫时,只有雌性死亡。在几种双纯合子双组分菌株和一种“全合一”菌株中,这两种成分在一个结构中都有,当在没有四环素的饮食中饲养时,雌性死亡发生在胚胎和/或第一龄幼虫阶段。对生产设施中大规模饲养相关表型的实验室评估显示,大多数菌株具有与目前在永久屏障中饲养释放的野生型J06菌株相似的适应度特征。在群体饲养条件下对“All in one”品系的测试表明,该品系保持了在小规模饲养中观察到的适合度特征。结论:本文描述的早期雌性致死菌株可由NWS控制计划选择,在生产设施中进行大规模检测,以提高NWS根除计划的效率。
期刊介绍:
BMC Genetics is an open access, peer-reviewed journal that considers articles on all aspects of inheritance and variation in individuals and among populations.