The bacterial gene Cys E and Cys M introduced in sheep are responsible for ________ .

The bacterial genes Cys E and Cys M encode enzymes responsible for the biosynthesis of the amino acid cysteine. Cysteine is a major component of keratin, which is the primary structural protein in wool. When these genes are introduced into sheep, they enable the sheep to synthesize their own cysteine, thereby increasing the formation of keratin protein and enhancing wool production.

Answer: increasing formation of keratin protein.