Abstract: The present invention provides compositions and methods for programming mammalian cells to perform desired functions. In particular, the present invention provides compositions and methods for programming stem cells to differentiate into a desired cell type. A quorum sensing systems that regulates the expression of cell fate regulators is introduced into mammalian host cells, such as stem cells. The quorum sensing systems generally comprises vectors that express the components of a bacterial quorum sensing pathway, including proteins which catalyze the synthesis of an autoinducer and a gene encoding a regulatory partner of the autoinducer, and vectors in which genes encoding cell fate regulators are operably linked to a promoter induced by the autoinducer/regulatory partner complex.

Abstract: The present invention provides compositions and methods for programming mammalian cells to perform desired functions. In particular, the present invention provides compositions and methods for programming stem cells to differentiate into a desired cell type. A quorum sensing systems that regulates the expression of cell fate regulators is introduced into mammalian host cells, such as stem cells. The quorum sensing systems generally comprises vectors that express the components of a bacterial quorum sensing pathway, including proteins which catalyze the synthesis of an autoinducer and a gene encoding a regulatory partner of the autoinducer, and vectors in which genes encoding cell fate regulators are operably linked to a promoter induced by the autoinducer/regulatory partner complex.

Abstract: The present invention provides compositions and methods for programming mammalian cells to perform desired functions. In particular, the present invention provides compositions and methods for programming stem cells to differentiate into a desired cell type. A quorum sensing systems that regulates the expression of cell fate regulators is introduced into mammalian host cells, such as stem cells. The quorum sensing systems generally comprises vectors that express the components of a bacterial quorum sensing pathway, including proteins which catalyze the synthesis of an autoinducer and a gene encoding a regulatory partner of the autoinducer, and vectors in which genes encoding cell fate regulators are operably linked to a promoter induced by the autoinducer/regulatory partner complex.

Abstract: The present invention provides compositions and methods for programming mammalian cells to perform desired functions. In particular, the present invention provides compositions and methods for programming stem cells to differentiate into a desired cell type. A quorum sensing systems that regulates the expression of cell fate regulators is introduced into mammalian host cells, such as stem cells. The quorum sensing systems generally comprises vectors that express the components of a bacterial quorum sensing pathway, including proteins which catalyze the synthesis of an autoinducer and a gene encoding a regulatory partner of the autoinducer, and vectors in which genes encoding cell fate regulators are operably linked to a promoter induced by the autoinducer/regulatory partner complex.

Abstract: The present invention provides compositions and methods for programming mammalian cells to perform desired functions. In particular, the present invention provides compositions and methods for programming stem cells to differentiate into a desired cell type. A quorum sensing systems that regulates the expression of cell fate regulators is introduced into mammalian host cells, such as stem cells. The quorum sensing systems generally comprises vectors that express the components of a bacterial quorum sensing pathway, including proteins which catalyze the synthesis of an autoinducer and a gene encoding a regulatory partner of the autoinducer, and vectors in which genes encoding cell fate regulators are operably linked to a promoter induced by the autoinducer/regulatory partner complex.

Abstract: The present invention provides compositions and methods for programming mammalian cells to perform desired functions. In particular, the present invention provides compositions and methods for programming stem cells to differentiate into a desired cell type. A quorum sensing systems that regulates the expression of cell fate regulators is introduced into mammalian host cells, such as stem cells. The quorum sensing systems generally comprises vectors that express the components of a bacterial quorum sensing pathway, including proteins which catalyze the synthesis of an autoinducer and a gene encoding a regulatory partner of the autoinducer, and vectors in which genes encoding cell fate regulators are operably linked to a promoter induced by the autoinducer/regulatory partner complex.

Abstract: The present invention provides an isolated interaction polynucleotide that contains a tag sequence and two or more genetic elements. The present invention also provides a method for identifying an interaction between two or more genetic elements. One embodiment of the present invention provides a method for analyzing and identifying the interaction between two or more genetic elements under various culture conditions or as a result of differentiation or pathological cellular development, wherein the genetic elements interact to stimulate or inhibit cell growth.

Abstract: The present invention provides methods for large-scale functional analysis of splicing variants. Specifically, the present methods provide polynucleotide probes that incorporate exon junction sequences arising from alternative splicing events. In one embodiment of this invention, the function of a splice variant is determined by identifying a polynucleotide comprising an exon junction that binds one or more polynucleotide isolated from sample cells yet binds a reduced amount or greater amount of polynucleotide isolated from sample cells exposed to altered conditions.

Abstract: The present invention relates to methods and compositions for assaying embryonic stem cell maintenance. In particular, the present invention provides reporter constructs for stem cell pluripotency and differentiation and cells and organisms containing such constructs.

Abstract: Isolated mammalian nucleic acid molecules encoding receptor protein tyrosine kinases expressed in primitive hematopoietic cells and not expressed in mature hematopoietic cells are provided. Also included are the receptors encoded by such nucleic acid molecules; the nucleic acid molecules encoding receptor protein tyrosine kinases having the sequences shown in FIG. 1a (murine flk-2), FIG. 1b (human flk-2) and FIG. 2 (murine flk-1); the receptor protein tyrosine kinases having the amino acid sequences shown in FIG. 1a, FIG. 1b and FIG. 2; ligands for the receptors; nucleic acid sequences that encode the ligands; and methods of stimulating the proliferation and/or differentiation of primitive mammalian hematopoietic stem cells comprising contacting the stem cells with a ligand that binds to a receptor protein tyrosine kinase expressed in primitive mammalian hematopoietic cells and not expressed in mature hematopoietic cells.

Abstract: Isolated mammalian nucleic acid molecules encoding receptor protein tyrosine kinases expressed in primitive hematopoietic cells and not expressed in mature hematopoietic cells are provided. Also included are the receptors encoded by such nucleic acid molecules; the nucleic acid molecules encoding receptor protein tyrosine kinases having the sequences shown in FIG. 1a (murine flk-2), FIG. 1b (human flk-2) and FIG. 2 (murine flk-1); the receptor protein tyrosine kinases having the amino acid sequences shown in FIG. 1a,FIG. 1b and FIG. 2; ligands for the receptors; nucleic acid sequences that encode the ligands; and methods of stimulating the proliferation and/or differentiation of primitive mammalian hematopoietic stem cells comprising contacting the stem cells with a ligand that binds to a receptor protein tyrosine kinase expressed in primitive mammalian hematopoietic cells and not expressed in mature hematopoietic cells.

Abstract: The present invention provides an isolated nucleic acid derived from an isolated hematopoietic stem cell. The present invention additionally provides an isolated hematopoietic stem cell specific protein or a portion thereof encoded by the provided nucleic acid. In addition, the present invention provides a method for generating a stem cell/progenitor cell from a primitive hematopoietic cell. Also, the present invention farther provides a method for identifying the presence in a sample of a compound that modulates hematopoietic stem cell activity. The present invention additionally provides a molecularly defined primitive hematopoietic stem cell. Finally, the present invention provides a method of ex vivo expansion of hematopoietic stem cells.