Provided is a temporary treatment medium for inhibiting embryo developmental arrest due to manipulation of an embryo or the like. A temporary treatment medium according to the present invention reduces damage to an in-vitro culture due to manipulation thereof, said in-vitro culture containing one of pluripotent stem cells, reproductive cells, a fertilized egg, and an embryo or any combination thereof. For this purpose, the temporary treatment medium contains a cytoskeleton regulator and/or an apoptosis inhibitor. The cytoskeleton regulator and/or the apoptosis inhibitor is preferably an Rho kinase inhibitor. Specifically, a Rock inhibitor can be used as the Rho kinase inhibitor. The Rock inhibitor is, for example, Y-27632. The temporary treatment medium is used for treating an in-vitro culture for a specific period before and/or after manipulation involving damage thereto.

Provided is a temporary treatment medium for inhibiting embryo developmental arrest due to manipulation of an embryo or the like. A temporary treatment medium according to the present invention reduces damage to an in-vitro culture due to manipulation thereof, said in-vitro culture containing one of pluripotent stem cells, reproductive cells, a fertilized egg, and an embryo or any combination thereof. For this purpose, the temporary treatment medium contains a cytoskeleton regulator and/or an apoptosis inhibitor. The cytoskeleton regulator and/or the apoptosis inhibitor is preferably an Rho kinase inhibitor. Specifically, a Rock inhibitor can be used as the Rho kinase inhibitor. The Rock inhibitor is, for example, Y-27632. The temporary treatment medium is used for treating an in-vitro culture for a specific period before and/or after manipulation involving damage thereto.

The present invention provides methods and compostions to improve the efficiency of somatic cell nuclear transfer (SCNT). There is increasing evidence that the epigenetic state of donor nuclei has a significant impact on potential of nuclear transfer embryos to develop into blastocysts, from which pluripotent stem cells are derived. Strategic application of histone agents, capable of altering epigenetic state such as methylation, allows zygotic activation and robust blastocyst generation.

Methods, uses, and animals for introgression of alleles between animals, including SNPs. One embodiment involves introducing a targeted targeting endonuclease system and a HDR template into a cell with a mismatch in the binding of the targeting endonuclease and the targeted site.

Described herein are methods of enhancing chromosomal homologous recombination to stimulate a loss of heterozygosity at a gene locus of interest in a living cell. These methods are driven by an enhancer component and a target-specific endonuclease component and proceed through a mechanism whereby: exogenous donor DNA that is homologous to the gene locus of interest is not introduced into the living cell; the desired allele of the gene locus of interest remains uncleaved; and the undesired allele is either uncleaved, cleaved at a single location, or cleaved at multiple locations. These methods have numerous applications, including the repair of risk alleles for disease prevention, the correction of heterozygous mutations in dividing cells, the design of cancer therapeutics, and the design of novel gene-drive strategies.

Described herein is a method for producing a chimeric non-human animal expressing a human ETV2 gene comprising: a) generating an ETV2 null non-human animal cell, wherein both copies of the non-human ETV2 gene carry a mutation that prevents production of functional ETV2 protein in said non-human animal; b) creating an ETV2 null non-human blastocyst by somatic cell nuclear transfer comprising fusing a nucleus from said ETV2 null non-human animal cell of a) into an enucleated non-human oocyte and activating said oocyte to divide so as to form an ETV2 null non-human blastocyst; c) introducing human stem cells into the ETV2 null non-human blastocyst of b); and d) implanting said blastocyst from c) into a pseudopregnant surrogate non-human animal to generate a chimeric non-human animal expressing human ETV2.

The invention provides double knockout transgenic pigs (GT/CMAH-KO pigs) lacking expression of any functional αGAL and CMAH. Double knockout GT/CMAH-KO transgenic organs, tissues and cells are also provided. Methods of making and using the GT/CMAH-KO pigs and tissue are also provided.

The present invention provides novel methods for improving the efficiency of artificial activation of unfertilized mammalian oocytes by reducing the intracellular concentration of Zn.sup.2+ in the oocyte. The methods of the invention may additionally comprise a preceding step of increasing the intracellular concentration of Ca.sup.2+ in the oocyte prior to reduction of the intracellular Zn.sup.2+ concentration. The invention further provides unfertilized oocytes activated by the disclosed methods and viable mammalian animals produced from unfertilized oocytes activated by the disclosed methods.

The present invention provides novel methods for improving the efficiency of artificial activation of unfertilized mammalian oocytes by reducing the intracellular concentration of Zn.sup.2+ in the oocyte. The methods of the invention may additionally comprise a preceding step of increasing the intracellular concentration of Ca.sup.2+ in the oocyte prior to reduction of the intracellular Zn.sup.2+ concentration. The invention further provides unfertilized oocytes activated by the disclosed methods and viable mammalian animals produced from unfertilized oocytes activated by the disclosed methods.

Semen and sperm cell processing and preservation systems, and methods of producing a mammal and methods of producing mammalian embryos are disclosed. The present invention is directed to sperm cell preservation, fertilization, and insemination, maintaining or enhancing sperm quality and addressing one or more sperm cell characteristics, such as viability, motility, functionality, fertilization rates, and pregnancy rates. Further, sperm cell characteristics may be addressed within the context of various collection, handling, separation, storage, transportation, usage, fertilization, or insemination techniques.