T7 Phage (image) University of Texas at Austin Share Print E-Mail Caption Researchers found that the T7 virus has six tail fibers that are folded back against its capsid. The fibers extend as the virus locates a suitable host and as it "walks" across its host cell surface to find a site to infect. Credit From Hu et. al. 2013. Science Express. Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.