Abstract: There are provided a method of producing a placenta-like organoid that can be subjected to long-term culture, a placenta-like organoid that is produced by the above producing method, and a production or test kit that contains the above placenta-like organoid. The method of producing a placenta-like organoid includes subjecting a pluripotent stem cell to suspension culture in the presence of a bone morphogenetic protein BMP4.

Abstract: The method for producing a cell construct including small intestinal epithelial cells includes: seeding stem cells onto cell culture substrate, the cell culture substrate having surface including cell culture part, wherein the cell culture part includes non-cell-adhesive part, and cell-adhesive part extending continuously or intermittently along periphery of the non-cell-adhesive part and surrounding the non-cell-adhesive part; and culturing the stem cells seeded to differentiate a part of the stem cells into small intestinal epithelial cells.

Abstract: A gut organoid includes a tissue structure that encloses a cavity. A method of using the gut organoid includes providing a test drug to the gut organoid in the presence of a buffer solution so that liquid comprising the test drug enters into the cavity, and collecting and analyzing the liquid in the cavity. A method for producing the gut organoid includes plating cells on a cell culture substrate including a surface on which a cell-adhesive region and a non-cell-adhesive region surrounding the cell-adhesive region are formed, and culturing the cells plated on the cell culture substrate so as to induce differentiation of the cells.

Abstract: An object of the present invention is to provide a cell culture method having excellent cell proliferation ability by a simple process and a medium and a culture medium kit used in the cell culture method described above. The present invention provides a cell culture method including: culturing cells in a medium in which a human-type recombinant protein is dissolved, in which the human-type recombinant protein is laminin, collagen, gelatin, or a variant thereof, and a content of the human-type recombinant protein in the medium is 0.01 ng/mL to 500 ?g/mL.

Abstract: The present invention provides a method, upon introducing an extracellular substance, such as sperm, a cell nucleus, a nucleic acid, and a protein, into a mammalian oocyte, for introducing the extracellular substance into a mammalian oocyte, which is safe for the mammalian oocyte, enables efficient introduction, and is technically easy. By treating the mammalian oocyte with a tubulin-polymerization inhibitor such as vinblastine, membrane fusion between the oocyte and the sperm is promoted, and the sperm and the oocyte are fused without making a hole in the oolemma and fertilization can be achieved. The method of the present invention can be applied not only to the case of introducing sperm into a mammalian oocyte, but also to the case of introducing an extracellular substance, such as a cell nucleus, a nucleic acid, and a protein, into a mammalian oocyte.

Abstract: The present invention provides methods of preparing spermatozoa suitable for use in ICSI-mediated transgenesis, wherein the methods include the suspension of spermatozoa in a buffered medium comprising an ion-chelating agent. In a preferred embodiment of the invention, the method of preparing spermatozoa for ICSI-mediated transgenesis further comprises treatment of membrane-disrupted or demembranated spermatozoa with a disulfide reducing agent. Also provided are spermatozoa suitable for use in ICSI-mediated transgenesis, wherein the exogenous nucleic acid to be co-inserted in an unfertilized oocyte via ICSI is closely associated with the membrane-disrupted or demembranated spermatozoon.

Abstract: A method of producing a non-human mammalian embryo, such as a mouse embryo, by nuclear cloning, in which the nucleus from a non-human mammalian embryonic stem (ES) cell (e.g., a non-human mammalian F1 ES cell), such as the nucleus of a mouse F1 ES cell, is introduced into an enucleated non-human mammalian oocyte, such as an enucleated mouse oocyte; embryos produced by the method; a method of producing mice from the resulting embryos and the mice produced thereby.