| الوصف: |
Clustering groups phages with significant nucleotide and proteome similarities together; phages with relatively unique genome properties are instead classified as Singletons. Multiple established clusters and Singletons reflect the vast genome diversity of phages — currently, there are 136 clusters and 94 singletons. Recently a brand new cluster, FI, was formed to include Arthrobacter phages Whytu and Yavru. In this study, we focused on Whytu, which was initially a Singleton, but became the first member of Cluster FI. Since Whytu was grouped into a new cluster, if Whytu is unique compared to non-FI phages, then comparative genome analysis (BLASTn, Dotplots, OrthoANI, and Phamerator) should reveal great nucleotide and proteomic differences between Whytu and non-FI phages. Intracluster comparative genomic analyses were first performed to understand the reclassification of formerly Singleton Whytu into Cluster FI with Yavru. As expected, Whytu and Yavru share high nucleotide and proteome similarity, but differ in regions coding for a minor tail protein and lysin A. A phylogenetic tree of lysin A gene suggested that Whytu’s lysin A may have been acquired through methods other than vertical inheritance. Contrary to our expectations, intercluster comparisons revealed high gene content similarity between Cluster FI phages, Singleton BlueFeather, and Cluster FE phages, which together comprise the top BLASTn hits. Despite high gene content similarity, however, there was high nucleotide dissimilarity suggesting that aside from Yavru, Whytu’s nucleotide profile is highly unique. Findings from this study thus give further insight into phage diversity and add to the growing field of phage biology. |