Particle for the encapsidation of a genome engineering system

A retroviral particle, comprising a protein derived from the Gag polyprotein, an envelope protein, optionally an integrase, and at least two encapsidated non-viral RNAs, the encapsidated non-viral RNAs each comprising an RNA sequence of interest bound to an encapsidation sequence, each encapsidation sequence being recognized by a heterologous binding domain introduced into the protein derived from the Gag polyprotein and/or into the integrase, in which the at least two encapsidated non-viral RNAs differ by their sequence of interest, wherein:

• at least one of said sequences of interest of the encapsidated non-viral RNAs comprises a part coding for a nuclease, said nuclease being chosen from the group constituted by a nuclease associated with CRISPR system;
• and
• the sequence of interest of the other encapsidated non-viral RNA corresponds to at least one recognition element of a guide RNA.