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.
