Abstract: A gene is provided, which can be used as a marker for determining whether a certain cell, particularly an undifferentiated cell including a tissue stem cell, has pluripotency or an undifferentiated state. The gene is called Stm and includes a Stm1 gene, which is expressed specifically in a cell under an undifferentiated state if the cell has pluripotency. A kit for determining a differentiated state of a cell is also provided. The kit comprises (a) an agent capable of reacting specifically with a Stm gene or a Stm gene product; and (b) means for determining whether or not the Stm gene is expressed in the cell.

Abstract: The present invention provides a method for preparing a mature hepatocyte from an embryonic stem cell in vitro, comprising: (a) culturing the embryonic stem cell so as to differentiate into an endodermal cell; (b) isolating the endodermal cell from a population of the differenciated cell; and (c) culturing the isolated endodermal cell in the presence of a Thy 1-positive mesenchymal cell.

Abstract: A method for producing a monkey-derived embryonic stem cell comprising the steps of carrying out fertilization by insemination by in vitro fertilization or intracytoplasmic sperm injection using a monkey ovum and monkey sperms, thereby giving a fertilized ovum, allowing the fertilized ovum to differentiate into a blastocyst by in vitro culture, and establishing an ES cell line using the blastocyst; the monkey ES cell obtained by the method, a method for screening a reagent for specific differentiation into cell or tissue by using the ES cell; and a differentiated cell or differentiated tissue each differentiated from the ES cell. According to the present invention, applications of the embryonic stem cells to embryological studies clinical applications, experimental models, and the like on primates, studies of diseases, are expected.

Abstract: By exposing somatic cells to a component derived from ES cells to act on somatic cells and detecting the activity thereof, the reprogramming agent can be screened. Further, by exposing somatic cells to a component including a reprogramming agent or an isolated reprogramming agent, the somatic cells can be reprogrammed. Furthermore, according to the present invention, since the tetraploid cells have proliferating capability and pluripotency, such cells can be differentiated and the cells, tissues or organs, which can be used for transplantation, can be produced.

Abstract: An object of the present invention is to efficiently establish cells, tissues, and organs capable of serving as donors for treating diseases, without eliciting immune rejection reactions, without starting with an egg cell. This object was achieved by providing a pluripotent stem cell having a desired genome. The cell was produced by treating with a reprogramming agent, producing a fusion cell of an MHC deficient stem cell with a somatic cell, or after producing a fusion cell of a stem cell with a somatic cell, removing a gene derived from the stem cell by performing genetic manipulation with a retrovirus.

Abstract: A cryopreservation medium and a cryopreservation method which make it possible to cryopreserve ES cells from primates simply with high viability are provided. A cryopreservation medium containing a cryoprotectant at a Concentration of from 12% (W/V) to 50% (W/V) and a cryopreservation method for primate embryonic stem cells, which comprises a step of suspending primate embryonic stem cells in the cryopreservation medium, and a refrigeration step of freezing the suspension of the primate embryonic stem cells in the cryopreservation medium by cooling it to ?80° C. or below at a rate of from 0.5° C. to 10° C. per minute, and a preservation step of storing the frozen suspension of primate embryonic stem cells in the cryopreservation medium enable simple cryopreservation of primate embryonic stem cells with high viability.

Abstract: A method for producing a monkey-derived embryonic stem cell comprising the steps of carrying out fertilization by insemination by in vitro fertilization or intracytoplasmic sperm injection using a monkey ovum and monkey sperms, thereby giving a fertilized ovum, allowing the fertilized ovum to differentiate into a blastocyst by in vitro culture, and establishing an ES cell line using the blastocyst; the monkey ES cell obtained by the method, a method for screening a reagent for specific differentiation into cell or tissue by using the ES cell; and a differentiated cell or differentiated tissue each differentiated from the ES cell. According to the present invention, applications of the embryonic stem cells to embryological studies clinical applications, experimental models, and the like on primates, studies of diseases, are expected.

Abstract: An enzyme solution for subculturing primate embryonic stem (ES) cells and a method of culturing primate ES cells is described herein. The enzyme solution comprises trypsin, calcium chloride and a serum substitute. The culturing method comprises the step of culturing primate ES cells in a solution comprising trypsin and calcium chloride, and optionally a serum substitute. The solution and method of this invention enable one to stably maintain and propagate ES cells derived from a primate, such as monkey or human, for a long period in an undifferentiated state and with a normal karyotype.

Abstract: A novel and efficient method for production of a transgenic animal is developed. This invention provides a method for production of a novel transgenic animal comprising the steps of introducing a foreign gene into testis of an animal, selecting transfected spermatocytes, spermatids or spermatozoa in which the foreign gene was introduced using a fluorescence marker gene as an indicator and fertilizing an unfertilized oocyte or ovum with the transfected spermatocyte, spermatid or spermatozoa.

Abstract: Disclosed is a cosmetic composition comprising a glutathione/.alpha.-cyclodextrin and/or .beta.-cyclodextrin inclusion complex.The cosmetic composition of the present invention has the effects of glutathione on the skin and is free of an offensive odor of glutathione.