Regulation of DNA packaging and transfer in extracellular vesicles

细胞间遗传物质在繁殖之外的转移是水平基因转移，在细菌种群中很常见。基因交换改变了微生物的活性和功能。控制基因交换将使新的实验方法能够理解微生物群落的功能，并将有助于先进生物技术的发展。水平基因转移的三种传统机制是转导、转化和接合，尽管大多数细菌物种产生的细胞外囊泡也促进基因交换。这项研究将分析影响细菌种群内细胞外囊泡的产生和交换的参数，以更好地了解细胞如何利用细胞外囊泡进行基因交换。更广泛的影响将通过与当地STEM组织合作来实现，以开发实践活动，向初中和高中学生教授基因组的生物物理学，并为学习生物物理学的本科生开发生物过程的定量建模课程。囊泡介导的基因转移可能是微生物种群内基因交换的通用途径，尽管通过囊泡调节基因交换效率的参数仍不清楚。该项目研究了含有细胞外囊泡的DNA的形成和摄取如何受到交换的遗传物质以及供体和受体细菌物种的特征的影响，包括外膜的特性。转座子诱变筛选将揭示调节囊泡介导的基因转移的动力学的其他因素。将通过实验测量和理论建模将基因转移到野生分离株中，以评估囊泡对野生种群基因交换的贡献。对囊泡中基因转移动力学过程的定量理解将有助于制定控制微生物种群中特定遗传成分转移的策略。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

The transfer of genetic material between cells outside of reproduction is horizontal gene transfer and is common within bacterial populations. Gene exchange changes the activity and functional capabilities of microbes. Control of gene exchange will enable new experimental methods to understand the function of microbial communities and will aid in the development of advanced biotechnologies. Three traditional mechanisms of horizontal gene transfer are transduction, transformation, and conjugation, although extracellular vesicles made by most bacterial species also facilitate gene exchange. This research will analyze the parameters that impact the production and exchange of extracellular vesicles within bacterial populations to better understand how cells utilize extracellular vesicles for gene exchange. The broader impacts will be achieved through work with local STEM organizations to develop hands-on activities to teach middle and high school students the biophysics of the genome as well as developing a quantitative modeling of biological processes course for undergraduates studying biophysics. Vesicle-mediated gene transfer may be a universal route of gene exchange within microbial populations, although parameters that modulate the efficiency of gene exchange through vesicles remain unclear. The project examines how the formation and uptake of DNA containing extracellular vesicles are influenced by characteristics of the exchanged genetic material and the donor and recipient bacterial species, including properties of the outer membrane. Transposon mutagenesis screens will reveal additional factors that regulate the dynamics of vesicle-mediated gene transfer. Gene transfer into wild isolates will be experimentally measured and theoretically modeled to assess the contribution of vesicles to gene exchange in wild populations. A quantitative understanding of the processes that shape the dynamics of gene transfer in vesicles will help formulate strategies to control the transfer of specific genetic components within microbial populations.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.