Biochemistry and Molecular Biology
Penn State Science
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Tim Miyashiro

Tim Miyashiro

Main Content

  • Assistant Professor of Biochemistry and Molecular Biology
410 South Frear Laboratory
University Park, PA 16802
Phone: (814) 865-1916

Research Interests

  • Bacterial gene expression within natural host environments; 
  • Host-microbe symbioses

Graduate Programs


Research Summary

The overall goal of the Miyashiro lab is to understand how bacteria regulate gene expression within a host environment.  Natural symbioses, which typically exhibit extraordinary host-microbe specificity as a result of coevolution, offer ideal systems to examine bacterial gene regulation within the context of host environments.  Our lab takes advantage of the symbiosis established between the bioluminescent bacterium, Vibrio fischeri, and the Hawaiian squid, Euprymna scolopesE. scolopes harbors populations of V. fischeri as a source of light within a specialized structure called the light organ.  The squid, which is a nocturnal animal, is thought to use this bioluminescence for various behaviors such as counter-illumination.

Bacterial transmission in the squid-vibrio symbiosis is horizontal, i.e., juvenile squid hatch from their eggs un-colonized and acquire their symbionts from the surrounding seawater.  As a result, we can study the initial steps of bacterial colonization within the lab.  We examine general microbiology themes such as phenotypic variation in gene expression, crosstalk in bacterial signaling systems, and bacterial modulation of host-microbe interactions.  To investigate these themes, our lab uses approaches based on single-cell microscopy, molecular genetics, and bioinformatics techniques.

Selected Publications


  • Miyashiro T and Ruby EG. 2012. Shedding light on bioluminescence regulation in Vibrio fischeri. Mol Microbiol. 84: 795-806. PMCID: PMC3359415
  • Cao X, Studer S, Wasserman KM, Zhang Y, Ruby EG, and Miyashiro T. 2012. The Novel Sigma Factor-like Regulator RpoQ Controls Luminescence, Chitinase Activity and Motility in Vibrio fischeri. mBio 3: e00285-11. PMCID: PMC3252764
  • Miyashiro T, Klein W, Oehlert D, Cao X, Schwartzman J, and Ruby EG. 2011. The N-acetyl-D-glucosamine repressor NagC of Vibrio fischeri facilitates colonization of Euprymna scolopes. Mol Microbiol 82: 894-903. PMCID: PMC3212624 Cover illustration for issue
  • Miyashiro T, Wollenberg MS, Cao X, Oehlert D, and Ruby EG. 2010. A single qrr gene is necessary and sufficient for LuxO-mediated regulation in Vibrio fischeri. Mol Microbiol 77: 1556-67. PMCID: PMC2947852
  • Miyashiro T and Goulian M. 2008. High Stimulus Unmasks Positive Feedback in an Autoregulated Bacterial Signaling Circuit. Proc Natl Acad Sci U S A. 105: 17457-62. PMCID: PMC2582279 Recommended [6] by Faculty of 1000
  • Liu Z, Miyashiro T, Tsou A, Hsiao A, Goulian M, and Zhu J. 2008. Mucosal Penetration Primes Vibrio cholerae for Host Colonization by Repressing Quorum Sensing. Proc Natl Acad Sci U S A. 105: 9769-74. PMCID: PMC2474479
  • Miyashiro T and Goulian M. 2007. Stimulus-Dependent Differential Regulation in the Escherichia coli PhoQ-PhoP System. Proc Natl Acad Sci U S A 104: 16305-10. PMCID: PMC2042202
  • Miyashiro T and Goulian M. 2007. Single-Cell Analysis of Gene Expression by Fluorescence Microscopy. Methods Enzymol 423:458-75. PMID: 17609146

*Underlined names indicate undergraduate students.