Why do bacteriophage encode tRNAs?

这个项目研究噬菌体-细菌相互作用系统，围绕噬菌体tRNAs的使用和进化选择。它主要集中在理解为什么噬菌体编码tRNA，以及tRNA如何影响噬菌体宿主范围和噬菌体毒力。进一步的研究路线将包括检查是否有证据表明细菌宿主和噬菌体在宿主和噬菌体基因组中观察到的tRNAs差异存在共同进化。另一种研究途径将是检查噬菌体tRNA和细菌密码子是否编码相同或不同的tRNA，如果是，是哪一个。这个项目的目标是创建一个使用大肠杆菌和T4噬菌体的模型系统。将创建T4突变体，将T4内编码的每个tRNA系统地敲除，并将这些突变体的毒力和宿主范围与T4“野生型”噬菌体的毒力和宿主范围进行比较。同时，该项目将进行生物信息学和生物统计学研究，以调查已知和测序的噬菌体及其宿主内tRNA的差异和使用差异。这将包括将全基因组分析所建议的噬菌体系统进化与编码tRNA所建议的噬菌体的预测进化进行比较。将编码的tRNAs与细菌宿主编码的tRNAs的进化进行比较，将有助于了解细菌的tRNAs是否有规律和随机地被噬菌体获得，它们是否在历史宿主的噬菌体基因组中高度保守，或者噬菌体基因组中tRNAs的变化可能是由于随机突变但仍处于选择性进化压力下。

This project examines bacteriophage-bacterial interaction systems, surrounding the use of and evolutionary selection for bacteriophage tRNAs. It primarily focuses understanding why bacteriophage encode for tRNAs, and how tRNAs impact bacteriophage host range and bacteriophage virulence. Further routes of investigation will include examining if there is evidence of co-evolution of bacterial hosts and bacteriophage, with respect to observed differences in tRNAs in the host and bacteriophage genomes. Another route of investigation will be to examine if bacteriophage tRNAs and bacterial codons are coding for the same or different tRNAs, and if so, which ones.This project will aim to create a model system using E. coli and T4 bacteriophage. T4 mutants will be created which have each tRNA encoded within T4 systematically knocked out, and these mutants' virulence and host range will be compared against the T4 "wild type" bacteriophage's virulence and host range. Concurrently, this project will undertake bioinformatics and biostatistics research to investigate differences and usage differences in tRNAs within known and sequenced bacteriophage and their hosts. This will involve comparing the phylogenetic evolution of bacteriophage as suggested by whole-genome analysis with the predicted evolution of bacteriophage as suggested by encoded tRNAs. Comparing the evolution based on encoded tRNAs against the tRNAs as encoded by their bacterial hosts will offer insight into whether bacterial tRNAs are regularly and randomly acquired by bacteriophage, if they are highly conserved within bacteriophage genomes from a historic host, or if changes in tRNAs in bacteriophage genomes may be due to random mutation but still under selective evolutionary pressures.