An oligomeric compound comprising at least one monomer of Formula II: wherein independently for each monomer of Formula II: Bx is a heterocyclic base moiety selected from adenine, guanine, thymine, cytosine, uracil and 5-methylcytosine; A is O; T 4 is an internucleoside linking group linking the monomer to the oligomeric compound, wherein each internucleoside linking group is, independently, a phosphodiester internucleoside linking group or phosphorothioate internucleoside linking group; and T 3 is a phosphorus moiety having the formula: wherein: R a and R c are each, independently, OH, SH, C 1 -C 6 alkyl, substituted C 1 -C 6 alkyl, C 1 -C 6 alkoxy, substituted C 1 -C 6 alkoxy, amino or substituted amino; and R b is O or S; each Q 1 is H and each Q 2 is methyl; or each Q 2 is H and each Q 1 is methyl; G 1 is selected from OCH 3, OCH 2 F, OCHF 2, OCF 3, OCH 2 CH 3, O(CH 2) 2 F, OCH 2 CHF 2, OCH 2 CF 3, OCH 2 -CH=CH 2, O(CH 2) 2 -OCH 3, O(CH 2) 2 -SCH 3, O(CH 2) 2 -OCF 3, O(CH 2) 3 -N(R 4)(R 5), O(CH 2) 2 -ON(R 4)(R 5), O(CH 2) 2 -O(CH 2) 2 -N(R 4)(R 5), OCH 2 C(=O)-N(R 4)(R 5), OCH 2 C(=O)-N(R 6)-(CH 2) 2 -N(R 4)(R 5) or O(CH 2) 2 -N(R 6)-C(=NR 7)[N(R 4)(R 5)] wherein R 4, R 5, R 6 and R 7 are each, independently, H or C 1 -C 6 alkyl; each substituted group comprises one or more optionally protected substituent groups independently selected from halogen, OJ 1, N(J 1)(J 2), =NJ 1, SJ 1, N 3, CN, OC(=L)J 1, OC(=L)N(J 1)(J 2) and C(=L)N(J 1)(J 2); L is O, S or NJ 3; each J 1, J 2 and J 3 is, independently, H or C 1 -C 6 alkyl; and wherein said oligomeric compound comprises from 8 to 40 monomeric subunits, is complementary to a target RNA and is capable of activating argonaute protein. Bx is a heterocyclic base moiety selected from adenine, guanine, thymine, cytosine, uracil and 5-methylcytosine; A is O; T 4 is an internucleoside linking group linking the monomer to the oligomeric compound, wherein each internucleoside linking group is, independently, a phosphodiester internucleoside linking group or phosphorothioate internucleoside linking group; and T 3 is a phosphorus moiety having the formula: wherein: R a and R c are each, independently, OH, SH, C 1 -C 6 alkyl, substituted C 1 -C 6 alkyl, C 1 -C 6 alkoxy, substituted C 1 -C 6 alkoxy, amino or substituted amino; and R b is O or S; R a and R c are each, independently, OH, SH, C 1 -C 6 alkyl, substituted C 1 -C 6 alkyl, C 1 -C 6 alkoxy, substituted C 1 -C 6 alkoxy, amino or substituted amino; and R b is O or S; each Q 1 is H and each Q 2 is methyl; or each Q 2 is H and each Q 1 is methyl; G 1 is selected from OCH 3, OCH 2 F, OCHF 2, OCF 3, OCH 2 CH 3, O(CH 2) 2 F, OCH 2 CHF 2, OCH 2 CF 3, OCH 2 -CH=CH 2, O(CH 2) 2 -OCH 3, O(CH 2) 2 -SCH 3, O(CH 2) 2 -OCF 3, O(CH 2) 3 -N(R 4)(R 5), O(CH 2) 2 -ON(R 4)(R 5), O(CH 2) 2 -O(CH 2) 2 -N(R 4)(R 5), OCH 2 C(=O)-N(R 4)(R 5), OCH 2 C(=O)-N(R 6)-(CH 2) 2 -N(R 4)(R 5) or O(CH 2) 2 -N(R 6)-C(=NR 7)[N(R 4)(R 5)] wherein R 4, R 5, R 6 and R 7 are each, independently, H or C 1 -C 6 alkyl; each substituted group comprises one or more optionally protected substituent groups independently selected from halogen, OJ 1, N(J 1)(J 2), =NJ 1, SJ 1, N 3, CN, OC(=L)J 1, OC(=L)N(J 1)(J 2) and C(=L)N(J 1)(J 2); L is O, S or NJ 3; each J 1, J 2 and J 3 is, independently, H or C 1 -C 6 alkyl; and wherein said oligomeric compound comprises from 8 to 40 monomeric subunits, is complementary to a target RNA and is capable of activating argonaute protein.