Abstract: The present invention provides a single-stranded nucleic acid molecule having a delivery function and capable of inhibiting expression of a target gene. The single-stranded nucleic acid molecule of the present invention is a single-stranded nucleic acid molecule composed of a region (Xc), a linker region (Lx) and a region (X), wherein said region (Xc) is complementary to said region (X), at least one of said region (X) and said region (Xc) contains an expression inhibitory sequence that inhibits expression of the target gene, and a bio-related substance having a delivery function is bonded to at least one selected from the group consisting of the 5?-terminus, the 3?-terminus, and said linker region (Lx).

Abstract: The present invention provides a natural type miRNA, which is a single-stranded nucleic acid containing X region and Y region, wherein the 3?-terminus of said X region and the 5?-terminus of said Y region are linked via a linker region of a non-nucleotide structure, the X region contains (a) a guide strand sequence or (b) a passenger strand sequence of a mature miRNA, when the X region contains (a), the Y region contains a passenger strand sequence of the mature miRNA, when the X region contains (b), the Y region contains a guide strand sequence of the mature miRNA, and the guide strand sequence and the passenger strand sequence form a double-stranded structure.

Abstract: The invention provides an artificial match-type miRNA utilizing miRNA. In particular, the invention provides a single strand nucleic acid containing an X region and a Y region, wherein the 3?-terminal of the X region and the 5?-terminal of the Y region are linked via a linker region of a non-nucleotide structure, the X region contains a guide strand sequence of a mature miRNA, and the Y region contains a sequence completely complementary to the X region is an artificial match-type miRNA. The artificial match-type miRNA can suppress expression of the target gene.

Abstract: The present invention provides a natural type miRNA, which is a single-stranded nucleic acid containing X region and Y region, wherein the 3?-terminus of said X region and the 5?-terminus of said Y region are linked via a linker region of a non-nucleotide structure, the X region contains (a) a guide strand sequence or (b) a passenger strand sequence of a mature miRNA, when the X region contains (a), the Y region contains a passenger strand sequence of the mature miRNA, when the X region contains (b), the Y region contains a guide strand sequence of the mature miRNA, and the guide strand sequence and the passenger strand sequence form a double-stranded structure.

Abstract: The present invention provides a single-stranded nucleic acid molecule having a delivery function and capable of inhibiting expression of a target gene. The single-stranded nucleic acid molecule of the present invention is a single-stranded nucleic acid molecule composed of a region (Xc), a linker region (Lx) and a region (X), wherein said region (Xc) is complementary to said region (X), at least one of said region (X) and said region (Xc) contains an expression inhibitory sequence that inhibits expression of the target gene, and a bio-related substance having a delivery function is bonded to at least one selected from the group consisting of the 5?-terminus, the 3?-terminus, and said linker region (Lx).

Abstract: The invention provides an artificial match-type miRNA utilizing miRNA. A In particular, the invention provides a single strand nucleic acid containing an X region and a Y region, wherein the 3?-terminal of the X region and the 5?-terminal of the Y region are linked via a linker region of a non-nucleotide structure, the X region contains a guide strand sequence of a mature miRNA, and the Y region contains a sequence completely complementary to the X region is an artificial match-type miRNA. The artificial match-type miRNA can suppress expression of the target gene.