16.3 Retroviruses may transduce cellular sequences Defective vins U5gag」 V-Onc U3R Helper vinus FU6 gag en「U3月 Proteins of helper virus can replicate: defective s Figure 16 10 Replication-defective transforming viruses have a cellular sequence substituted for part of the viral sequence The defective virus may replicate with the assistance of a helper virus that carries the wild-type functions 请莘大Figure 16.10 Replication-defective transforming viruses have a cellular sequence substituted for part of the viral sequence. The defective virus may replicate with the assistance of a helper virus that carries the wild-type functions. 16.3 Retroviruses may transduce cellular sequences