Abstract: The present invention provides a cell culture having a cartilage-like tissue forming property, including a cell population in which the expression intensity of at least one cell surface marker selected from the group consisting of CD166, CD165, CD99, GD2, STRO-1, CD108, CD164, CD6, CD106, and CD107b is not higher than the threshold for each cell surface marker, and/or, the expression intensity of at least one cell surface marker selected from the group consisting of CD26, CD73, CD105, CD44, CD120a, CD201, EGFR, CD146, CD140a, and CD90 is not lower than the threshold for each cell surface marker.

Abstract: A protein for visual color recognition and the like, the protein having a channel activity and including an amino acid residue different from the amino acid residue present in a first amino acid sequence represented by SEQ ID NO: 1, at a position or positions corresponding to one or two or more selections from the group consisting of the following positions in the first amino acid sequence: positions 53, 83, 87, 117, 120, 124, 137, 139, 142, 143, 146, 150, 169, 173, 177, 198, 204, 216, 217, 218, 231, 238, 245, and 247.

Abstract: An excellent photosensitivity is exhibited by a protein including, at a position or positions corresponding to one or two or more positions selected from the group made of the following (1) to (3) in a first amino acid sequence represented by SEQ ID NO: 1: (1) positions 39, 94, 98, 102, 110, 113, 114, 162, 224, 225, 230, 231, and 235, (2) positions 53, 61, 68, 74, 76, 80, 130, 137, 194, 195, 198, 200, 204, 205, 209, 210, 253, and 254, and (3) positions 46, 83, 84, 87, 90, 91, 116, 117, 120, 124, 139, 142, 143, 146, 173, 214, 216, 217, 238, 242, and 245, an amino acid residue different from that in the first amino acid sequence, and that has channel activity.