Question

The retroviral transfected DNA is infected into mammalian cells by helper retrovirus. Helper retrovirus should not be packaged and the method adopted for this is?

(a) Deletion of the packaging signal in the helper genome

(b) Deletion of multiple parts of the helper genome

(c) Division of the helper genome into several pieces

(d) All of the mentioned

I have been asked this question in an online interview.

Origin of the question is Cultured Cells in Mammals and Restricted Areas in Intact Organisms topic in section Using Other Organisms of Genetic Engineering

Answer 1

Correct option is (d) All of the mentioned

To explain: Helper retrovirus is used for introduction of transfected DNA into mammalian cells. But it is necessary that helper retrovirus itself should not be packaged. It can be achieved by deletion of the packaging signal in the helper genome, deletion of multiple parts of the helper genome and division of the helper genome into several pieces.