T7 Phage (image) University of Texas at Austin 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 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.