Abstract: A method of retrovirus storage, characterized in that a retrovirus is sustained in the presence of a substance with retrovirus binding activity immobilized on a solid phase. Further, there is provided a retrovirus composition characterized in that a retrovirus in the form of binding to a substance with retrovirus binding activity is sealed in a container holding a solid phase having the substance with retrovirus binding activity immobilized thereon.

Abstract: The N-acetylglucosaminyltransferase III activity is enhanced in a cell carrying retrovirus-origin gag-pol gene and env gene. By constructing a retrovirus vector with the use of the above cell, a retrovirus vector having a modified sugar chain structure can be obtained. The retrovirus vector constructed by this method shows a high infection efficiency particularly in the presence of a functional substance.

Abstract: A complex comprising a double-stranded DNA containing a terminal repeated sequence originating in a retrovirus and a DNA having a base sequence which does not occur in this retrovirus and a retrovirus-origin protein component.

Abstract: Improved methods for transferring a gene into target cells by using a retrovirus, wherein the gene transfer efficiency is improved and the target cells are efficiently transformed by binding the retrovirus to a functional substance which is immobilized on as carrier and having an activity of binding to retroviruses followed by washing; using an antibody capable of specifically recognizing cells, laminin or mannose-rich type sugar chain as a substance having an activity of binding to the target cells; pre-treating the target cells so as to inactivate transferring receptor, or introducing a new functional group into the functional substance.

Abstract: A complex comprising a double-stranded DNA containing a terminal repeated sequence originating in a retrovirus and a DNA having a base sequence which does not occur in this retrovirus and a retrovirus-origin protein component.

Abstract: Improved methods for transferring a gene into target cells by using a retrovirus, wherein the gene transfer efficiency is improved and the target cells are efficiently transformed by binding the retrovirus to a functional substance which is immobilized on as carrier and having an activity of binding to retroviruses followed by washing; using an antibody capable of specifically recognizing cells, laminin or mannose-rich type sugar chain as a substance having an activity of binding to the target cells; pre-treating the target cells so as to inactivate transferrin receptor, or introducing a new functional group into the functional substance.

Abstract: Improved methods for transferring a gene into target cells by using a retrovirus, wherein the gene transfer efficiency is improved and the target cells are efficiently transformed by binding the retrovirus to a functional substance which is immobilized on as carrier and having an activity of binding to retroviruses followed by washing; using an antibody capable of specifically recognizing cells, laminin or mannose-rich type sugar chain as a substance having an activity of binding to the target cells; pre-treating the target cells so as to inactivate transferrin receptor, or introducing a new functional group into the functional substance.

Abstract: Killifish genes which are expressed specifically to females in accordance with the phenotype sex, characterized by having a base sequence selected from among the base sequences represented by SEQ ID NOS: 1 to 21 in Sequence Listing.

Abstract: An antiviral agent which is characterized in containing at least one compound selected from a group consisting of 4,5-dihydroxy-2-cyclopenten-1-one represented by the following formula [I] and an optically active substance and a salt thereof as an effective component.

Abstract: An antiviral agent which is characterized in containing at least one compound selected from a group consisting of 4,5-dihydroxy-2-cyclopenten-1-one represented by the following formula [I] and an optically active substance and a salt thereof as an effective component.

Abstract: A compound represented by the following formula [I] or an optically active substance or a salt thereof. (In the formula, a bond shown by a dotted line in the five-membered ring means that said five-membered ring may be any of a cyclopentene ring having a double bond and a cyclopentane ring where said bond is saturated and, in the case of a cyclopentene ring, X is OH, Y is ═O and Z is H while, in the case of a cyclopentane ring, X is ═O, Y is OH and Z is OH. R is a residue after removal of an SH group from the SH-containing compound.