Abstract: An object of the present invention is to provide a polynucleotide having a modification site in a translated region with translation activity retained. The object can be achieved by a polynucleotide containing a translated region from a start codon to a stop codon, in which the translated region contains n codons, and the n is a positive integer of 2 or more, each of the n codons contains first, second and third nucleotides, and the first nucleotides in at least two codons of the n codons are sugar modified nucleotides.

Abstract: The present invention provides, for example, an oligonucleotide derivative or a salt thereof comprising a circular oligonucleotide and a linear oligonucleotide, wherein the circular oligonucleotide and the linear oligonucleotide have base sequences complementary to each other, and form a complex via a hydrogen bond between the complementary base sequences, and a method for producing the same.

Abstract: An oligonucleotide having improved affinity for AGO2 is disclosed. The oligonucleotide has a nucleotide residue or a nucleoside residue represented by formula (I) wherein X1 is an oxygen atom or the like, R1 is formula (IIA), wherein R5A is halogen or the like, and R6A is a hydrogen atom or the like, or formula (IVA) wherein Y3A is a nitrogen atom or the like, and Y4A is CH or the like, or the like, R2 is a hydrogen atom, hydroxy, halogen, or optionally substituted lower alkoxy, and R3 is a hydrogen atom or the like at the 5? end thereof, and the nucleotide residue or the nucleoside residue binds to an adjacent nucleotide residue through the oxygen atom at position 3. A method for improving the knockdown activity of an oligonucleotide wherein the oligonucleotide has a knockdown activity against an mRNA encoding a protein involved in a disease.

Abstract: An oligonucleotide having a nucleotide residue or a nucleoside residue represented by formula (I) {wherein X1 is an oxygen atom or the like, R1 is formula (IIA) (wherein R5A is halogen or the like, and R6A is a hydrogen atom or the like), formula (IVA) (wherein Y3A is a nitrogen atom or the like, and Y4A is CH or the like), or the like, R2 is a hydrogen atom, hydroxy, halogen, or optionally substituted lower alkoxy, and R3 is a hydrogen atom or the like, or formula (VI) (wherein n2 is 1, 2 or 3)} at the 5? end thereof, wherein the nucleotide residue or the nucleoside residue binds to an adjacent nucleotide residue through the oxygen atom at position 3, is provided.

Abstract: The present invention provides an oligonucleotide derivative having, at an oxygen atom of at least one phosphate group of an oligonucleotide, a group represented by formula (I): (wherein R1 represents lower alkyl or the like; and R2 and R3 are the same or different and respectively represent an electron-withdrawing group or the like), or a salt thereof.

Abstract: An oligonucleotide having a nucleotide residue or a nucleoside residue represented by formula (I) {wherein X1 is an oxygen atom or the like, R1 is formula (IIA) (wherein R5A is halogen or the like, and R6A is a hydrogen atom or the like), formula (IVA) (wherein Y3A is a nitrogen atom or the like, and Y4A is CH or the like), or the like, R2 is a hydrogen atom, hydroxy, halogen, or optionally substituted lower alkoxy, and R3 is a hydrogen atom or the like, or formula (VI) (wherein n2 is 1, 2 or 3)} at the 5? end thereof, wherein the nucleotide residue or the nucleoside residue binds to an adjacent nucleotide residue through the oxygen atom at position 3, is provided.

Abstract: The present invention provides an oligonucleotide having improved affinity for AGO2, and the like. The oligonucleotide has a nucleotide residue or a nucleoside residue represented by formula (I) {wherein X1 is an oxygen atom or the like, R1 is formula (IIA) (wherein R5A is halogen or the like, and R6A is a hydrogen atom or the like) or formula (IVA) (wherein Y3A is a nitrogen atom or the like, and Y4A is CH or the like), or the like, R2 is a hydrogen atom, hydroxy, halogen, or optionally substituted lower alkoxy, and R3 is a hydrogen atom or the like} at the 5? end thereof, and the nucleotide residue or the nucleoside residue binds to an adjacent nucleotide residue through the oxygen atom at position 3.

Abstract: An oligonucleotide, which has a nucleotide residue or a nucleoside residue represented by formula (I) at the 5? end thereof, wherein the nucleotide residue or the nucleoside residue binds to an adjacent nucleotide residue via the oxygen atom at position 3, or the like; wherein X represents an oxygen atom or the like, R1 represents formula (II) wherein Y1 represents a nitrogen atom or the like, R5 represents halogen or the like, R6 and R7 may be the same or different, and each represents a hydrogen atom or the like, and R3 represents a hydrogen atom or the like.

Abstract: The present invention provides a composition that comprises a lipidparticle encapsulating a double-stranded nucleic acid molecule, wherein the antisense strand is a polynucleotide of 17 to 30 bases in which a sequence is complementary to the sequence of the 17 contiguous bases of a target gene's mRNA, the sense strand is a polynucleotide of 17 to 30 bases that contains a base sequence complementary to the base sequence of bases 1 to 17 in the 5?-end to 3?-end direction of the antisense strand, and a particular amount of the sugars binding to certain bases of the antisense strand and the sense strand are deoxyribose, or ribose whose hydroxyl group at the 2? position is substituted by a modifying group, and wherein the lipidparticle contains a lipid bilayer membrane whose constituent component is a lipid conjugate, a fatty acid conjugate or an aliphatic hydrocarbon conjugate of a water-soluble substance.

Abstract: The present invention provides a composition that comprises a lipidparticle encapsulating a double-stranded nucleic acid molecule, wherein the antisense strand is a polynucleotide of 17 to 30 bases in which a sequence is complementary to the sequence of the 17 contiguous bases of a target gene's mRNA, the sense strand is a polynucleotide of 17 to 30 bases that contains a base sequence complementary to the base sequence of bases 1 to 17 in the 5?-end to 3?-end direction of the antisense strand, and a particular amount of the sugars binding to certain bases of the antisense strand and the sense strand are deoxyribose, or ribose whose hydroxyl group at the 2? position is substituted by a modifying group, and wherein the lipidparticle contains a lipid bilayer membrane whose constituent component is a lipid conjugate, a fatty acid conjugate or an aliphatic hydrocarbon conjugate of a water-soluble substance.

Abstract: The present invention provides a composition that comprises a liposome encapsulating a double-stranded nucleic acid molecule, wherein the antisense strand is a polynucleotide of 17 to 30 bases in which a sequence is complementary to the sequence of the 17 contiguous bases of a target gene's mRNA, the sense strand is a polynucleotide of 17 to 30 bases that contains a base sequence complementary to the base sequence of bases 1 to 17 in the 5?-end to 3?-end direction of the antisense strand, and a particular amount of the sugars binding to certain bases of the antisense strand and the sense strand are deoxyribose, or ribose whose hydroxyl group at the 2? position is substituted by a modifying group, and wherein the liposome contains a lipid bilayer membrane whose constituent component is a lipid conjugate, a fatty acid conjugate or an aliphatic hydrocarbon conjugate of a water-soluble substance.