Abstract: A production method for a genetically modified megakaryocyte, the method including a step of introducing a CRISPR-associated (Cas) family protein and guide RNA (gRNA) into a megakaryocyte to modify a subject gene, in which the Cas family protein and the gRNA to be introduced into the megakaryocyte in the step form a complex beforehand. This production method is useful as a technique for producing a genetically modified megakaryocyte and a modified platelet.

Abstract: A production method of genomic DNA in which a deletion of more than 100 bases of nucleotides is introduced into a target region of the genomic DNA, the method includes a contact step of bringing a type I CRISPR associated complex for anti-viral defense (type I Cascade complex), CRISPR RNA (crRNA), and Cas3 protein into contact with the genomic DNA.

Abstract: A method for producing, from a donor cell, a low-antigenic cell in which a rejection reaction is reduced in a case where the cell is allogeneically transplanted into a recipient, the method including: determining human leukocyte antigen (HLA) alleles for the donor cell and the recipient, respectively; specifying an HLA allele that is present in the donor cell but is not present in the recipient; and disrupting or modifying the specified HLA allele to obtain a cell population including a cell not expressing an HLA protein specific to the donor cell, in which the cell not expressing the HLA protein specific to the donor cell is the low-antigenic cell.