Abstract: Provided herein are three-dimensional co-culture systems, methods of using three-dimensional co-culture systems, and kits comprising three-dimensional co-culture systems.

Abstract: This disclosure is directed to culture media containing a nicotinamide adenine nucleotide (NAD+) precursor and/or a NAD pathway substrate. This disclosure is also directed to in vitro methods of improving the cell state in an embryo by contacting a mammalian embryo with a culture medium supplemented with a NAD+ precursor and/or a NAD pathway substrate. The improvements to the cell state may include increasing the presence of an expanded blastocyst, increasing the attachment rate of the embryo, and/or increasing the derivation of embryonic stem cells from the embryo. In certain embodiments, the media and methods use a NAD+ precursor. A variety of different NAD+ precursors can be used in the media and methods, including nicotinic acid (NA) and nicotinamide mononucleotide (NMN).

Abstract: This disclosure relates to methods of transfecting or transducing mammalian zygotes with a nucleic acid of interest (such as e.g., ancient DNA). The methods generally include manipulating the zona pellucida of a denuded zygote to increase permeability of the zona pellucida to a nucleic acid of interest. In certain embodiments, the manipulating of the zona pellucida of the denuded zygote includes removing the zona pellucida with enzymatic treatment (with e.g., acid Tyrode, collagenase, hyaluronidase, or pronase). In other embodiments, the manipulating of the zona pellucida of the denuded zygote includes puncturing 3 to 5 holes in a zona pellucida of a denuded zygote using a laser; and contacting the nucleic acid of interest with the denuded zygote under conditions allowing transfection to generate a transfected denuded zygote. The nucleic acid of interest may be on a vector such as a recombinant viral vector.

Abstract: Provided herein are methods of treating or preventing cancer in a subject in need thereof, the methods comprise administering to the subject in need thereof (a) one or more nucleic acids encoding an elephant p53 protein, an elephant LIF protein, and/or combinations thereof, or (b) one or more elephant p53 proteins, elephant LIF proteins, and/or combinations thereof. Also provided are pharmaceutical compositions comprising a pharmaceutically acceptable carrier and (a) one or more nucleic acids encoding an elephant p53 protein, an elephant LIF protein, and/or combinations thereof, or (b) one or more elephant p53 proteins, elephant LIF proteins, and/or combinations thereof.

Abstract: Provided herein are isolated nucleic acids comprising two or more nucleotide sequences capable of encoding genome-editing enzymes. Also provided are vectors comprising the isolated nucleic acids, host cells comprising the vectors, and kits comprising the isolated nucleic acids.

Abstract: Described herein are compositions and methods for generating a viable cell that expresses at least one or more woolly mammoth genes. Also described herein are compositions and methods for generating an embryo, blastula, oocyte, or non-human organism that expresses one or more woolly mammoth genes.

Abstract: The present disclosure provides methods and compositions of altering a target nucleic acid sequence in a cell. The methods comprise introducing into the cell a guide RNA comprising a portion that is complementary to all or a portion of the target nucleic acid sequence, introducing into the cell a Cas9 transposase fusion protein, and introducing into the cell a donor nucleic acid sequence, wherein the guide RNA and the Cas9 transposase fusion protein co-localize at the target nucleic acid sequence, wherein the Cas9 transposase fusion protein cleaves the target nucleic acid sequence and the donor nucleic acid sequence is inserted into the target nucleic acid sequence in a site specific manner.