Since phages use the host resources to replicate themselves after infection, the different sizes of the phage genome should influence the replication rate. We, therefore, hypothesized that the smaller genomes should burst the cell faster than the larger ones. As well, the shorter genomes would have greater burst sizes because they should replicate faster. Here, we obtained 16 phages of various genome length. All phages were isolated on Streptomyces griseus and available in our phage bank at the University of North Texas. We performed one-step growth studies for the 16 phages, as well as determined the host doubling time from its growth curve. The results show that S. griseus grown in nutrient broth has a doubling time of 5 hours and 22 minutes. This doubling time is used as a guideline for the phage growth studies. Because the filamentous nature of the host caused several difficulties during the experiment, we isolated single cells by sonication and centrifugation. After the cell number was determined by viable cell count, the cells were infected with each type of phage using a multiplicity of infection (MOI) of 0.5. The results show that phages' burst times range between 45 (±0, standard error) and 420 (±30) minutes and burst sizes from 12 (±0) to 1500 (±60) The statistical analyses show that there is no correlation between either genome size and burst time (R= -0.01800, P=0.97894) or genome size and burst size (R= -0.32678, P=0.21670). We further performed the comparative genomics studies to investigate whether the phages with similar burst times and burst sizes show similar genome structures. The studies show that Eddasa and Lorelei have similar burst times of 45 to 60 minutes and share 52 homologs. For burst size, only Tribute and Blueeyedbeauty that have similar burst sizes of 21-30, and they are genetically related because of the 48 shared homologs. Although this study did not find any correlation between genome size and burst time/burst size, it provides a foundation for further studies to determine what regulates these two traits.
| Identifer | oai:union.ndltd.org:unt.edu/info:ark/67531/metadc1505188 |
| Date | 05 1900 |
| Creators | Maneekul, Jindanuch |
| Contributors | Hughes, Lee E., Benjamin, Robert C., Azad, Rajeev K. |
| Publisher | University of North Texas |
| Source Sets | University of North Texas |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation |
| Format | viii, 65 pages, Text |
| Rights | Public, Maneekul, Jindanuch, Copyright, Copyright is held by the author, unless otherwise noted. All rights Reserved. |
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