Transgenic mice expressing fluorescent protein

A method of producing a non-human transgenic mammal which expresses a fluorescent protein in multipotent stem and progenitor cells, comprising:

• (a) introducing into a fertilized egg of a non-human mammal, DNA comprising a regulatory sequence of a mammalian nestin gene operably linked to a gene coding for a fluorescent protein that is expressed in multipotent stem and progenitor cells of the non-human mammal;
• (b) introducing the fertilized egg of (a) into a non-human mammal of the same species;
• (c) allowing the non-human mammal to produce progeny which are non-human transgenic mammals;
• and
• (d) selecting non-human mammal progeny of (c) whose multipotent stem and progenitor cells express the fluorescent gene.

A method for assessing a compound's ability to promote multipotent stem and progenitor cell differentiation, comprising:

• (a) contacting live multipotent stem and progenitor cells, which have integrated into their genome DNA comprising a regulatory sequence of a mammalian nestin gene operably linked to a gene coding for a marker/reporter protein wherein the gene coding for the marker/reporter protein is expressed in multipotent stem and progenitor cells, with a compound to be assessed;
• (b) determining a marker/reporter protein measurement of the live cells of a) in the presence of the compound;
• and
• (c) comparing the marker/reporter protein measurement of b) to the marker/reporter protein measurement of live control cells;
• wherein a decrease or absence of marker/reporter protein measurement of the live cells in the presence of the compound compared to the marker/reporter protein measurement of the live control cells is indicative of the compound's ability to promote multipotent stem and progenitor cell differentiation.

A method for assessing a compound's toxicity to multipotent stem and progenitor cells, comprising:

• (a) contacting live stem and progenitor cells, which have integrated into their genome DNA comprising a regulatory sequence of a mammalian nestin gene operably linked to a gene coding for a marker/reporter protein, wherein the gene coding for the marker/reporter protein is expressed in multipotent stem and progenitor cells, with a compound to be assessed;
• (b) determining live cells expressing the marker/reporter protein in the presence of the compound;
• and
• (c) comparing the live cells expressing the marker/reporter protein of b) to live, control cells expressing the marker/reporter protein;
• wherein a decrease or absence of live cells expressing the marker/reporter protein in the presence of the compound compared to the live control cells expressing the marker/reporter protein is indicative of the compound's toxicity to multipotent stem and progenitor cells.

A method for assessing a compound's ability to promote differentiation of totipotent cells into multipotent stem and progenitor cells, comprising:

• (a) contacting live totipotent stem and progenitor cells, which have integrated into their genome DNA comprising a regulatory sequence of a mammalian nestin gene operably linked to a gene coding for a marker/reporter protein, wherein the gene coding for the marker/reporter protein is expressed in multipotent stem and progenitor cells;
• (b) determining a marker/reporter protein measurement of the live cells of a) in the presence of the compound;
• and
• (c) comparing the marker/reporter protein measurement of b) to marker/reporter protein measurement of control cells;
• wherein an increase of marker/reporter protein measurement in the presence of the compound compared to the marker/reporter protein measurement of control cells is indicative of the compound's ability to promote differentiation of totipotent cells into multipotent stem and progenitor cells.