Provided herein are method to increase the efficiency of interspecies chimera generation.

The present invention has found that chimeric animals suffer from noticeable inflammation after birth, though neither immune response nor inflammation in the fetal period of these animals has been reported hitherto. This is an unexpected finding since chimeric animals in the fetal period were exclusively analyzed in prior studies and thus it is deemed that immunotolerance has been theoretically established therein. The present invention provides a composition for suppressing immune response or inflammation in the fetal period of a born chimeric animal.

The present invention relates to methods for transfecting cells. In particular, the present invention relates to methods of transfecting primordial germ cells in avians, and to methods of breeding avians with modified traits.

Described herein is a method for producing a chimeric non-human animal expressing a human NKX2-5, HANDII, TBX5 gene or a combination thereof gene comprising: a) generating a NKX2-5, HANDII, TBX5 or combination thereof null non-human animal cell, wherein both copies of the non-human NKX2-5, HANDII, TBX5 gene or combination thereof carry a mutation that prevents production of functional NKX2-5, HANDII, TBX5 protein or combination thereof in said non-human animal; b) creating a NKX2-5, HANDII, TBX5 or combination thereof null non-human blastocyst by somatic cell nuclear transfer comprising fusing a nucleus from said NKX2-5, HANDII, TBX5 or combination thereof null non-human animal cell of a) into an enucleated non-human oocyte and activating said oocyte to divide so as to form an NKX2-5, HANDII, TBX5 or combination thereof null non-human blastocyst; c) introducing human stem cells into the NKX2-5, HANDII, TBX5 or combination 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 NKX2-5, HANDII, TBX5 or combination thereof.

The present disclosure provides compositions and methods for the delivery of immune cells to treat un-resectable or non-resected tumor cells and tumor relapse. The compositions comprise (i) a structure comprising an injectable polymer or scaffold comprising pores; (ii) lymphocytes disposed within the structure, (iii) at least one lymphocyte-adhesion moiety associated with the structure; and (iv) at least one lymphocyte-activating moiety associated with the structure, and optionally an immune stimulant.

Methods and compositions are provided for generating F0 fertile XY female animals. The methods and compositions involve making XY pluripotent or totipotent animal cells, in vitro cell cultures, or embryos that are capable of producing a fertile female XY animal in an F0 generation. Such cells, embryos, and animals can be made by silencing a region of the Y chromosome. Optionally, the cells can also be cultured in feminizing medium such as a low-osmolality medium and/or can be modified to decrease the level and/or activity of an Sry protein. Methods and compositions are also provided for silencing a region of the Y chromosome in an XY pluripotent or totipotent animal cell, or in vitro cell cultures, embryos, or animals derived therefrom, by maintaining an XY pluripotent or totipotent animal cell in a feminizing medium. Methods and compositions are also provided for maintaining a population of XY pluripotent or totipotent animal cells in a feminizing medium and selecting cells or clones having increased capabilities for producing a fertile female XY animal in an F0 generation. Methods and compositions are also provided for screening for compounds with feminizing activity or for optimizing concentrations of components in feminizing media.

The present invention provides a method for preparing a somatic chimera by using a pluripotent cell genetically engineered not to differentiate into a predetermined type of cell. The present invention particularly provides a method for preventing a pluripotent cell from contributing to the brain and gonad in a somatic chimera animal.

In order to develop tools and methods useful in a variety of applications, including the research and development of medical treatments which involve the modification of collagen protein and use of the same, the present invention provides a modified collagen protein expressed in a transformed cell and capable of forming collagen fibers outside of said cell, wherein the transformation is performed by introducing, into the cell, into the cell, polynucleotides coding the modified collagen protein.

Provided herein are method to increase the efficiency of interspecies chimera generation.

Described herein is a method for producing a chimeric non-human animal expressing a human a MYF5, MYOD, MRF4 gene or a combination thereof gene comprising: a) generating an MYF5, MYOD, MRF4 or combination thereof null non-human animal cell, wherein both copies of the non-human MYF5, MYOD, MRF4 gene or combination thereof carry a mutation that prevents production of functional MYF5, MYOD, MRF4 protein or combination thereof in said non-human animal; b) creating a MYF5, MYOD, MRF4 or combination thereof null non-human blastocyst by somatic cell nuclear transfer comprising fusing a nucleus from said MYF5, MYOD, MRF4 or combination thereof null non-human animal cell of a) into an enucleated non-human oocyte and activating said oocyte to divide so as to form an MYF5, MYOD, MRF4 or combination thereof null non-human blastocyst; c) introducing human stem cells into the MYF5, MYOD, MRF4 or combination 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 MYF5, MYOD, MRF4 or combination thereof.