Production of a transgenic avian by cytoplasmic injection
View Patent ↗This invention provides methods for the stable introduction of heterologous coding sequences into the genome of a bird and expressing the coding sequences to produce desired proteins or to alter the phenotype of the bird. The present invention provides preferred methods for introducing a transgene into the cytoplasm of avian embryonic cells by cytoplasmic microinjection. The embryo then develops into a transgenic adult capable of expressing a heterologous protein and/or capable of generating a line of transgenic birds through breeding. Synthetic vectors and gene promoters useful in the methods are also provided by the present invention, as are transgenic birds that express heterologous protein and avian eggs containing heterologous protein.
1. A method of producing a transgenic avian comprising:
microinjecting into a cell of an avian embryo a nucleic acid comprising a transgene comprising a nucleotide sequence encoding a heterologous polypeptide;
introducing the microinjected avian embryo into an oviduct of a recipient hen, such that the recipient hen lays a shelled egg containing the microinjected avian embryo;
incubating the shelled egg containing the microinjected avian embryo until the egg hatches;
testing a hatched chick for the presence of the transgene; and
developing a chick that tests positive for the transgene to sexual maturity.
2. The method of claim 1 wherein the embryo is isolated from a hen.
3. The method of claim 1 wherein the embryo is a stage I embryo.
4. The method of claim 1 wherein the coding sequence is expressed in one or more cells of the transgenic avian.
5. The method of claim 1 where in the heterologous polypeptide is present in the serum of the transgenic avian.
6. The method of claim 1 where in the heterologous polypeptide is expressed in the magnum of the transgenic avian.
7. The method of 1 wherein the heterologous polypeptide is present in the white of an egg produced by the transgenic avian.
8. The method of claim 1 wherein the coding sequence is operably linked to a transcriptional regulatory element that can direct gene expression in one or more cells of the tranagenic avian.
9. The method of claim 8 wherein the transcriptional regulatory element is a promoter region of an avian gene which encodes a protein selected from the group consisting of ovalbumin, lysozyme, ovomucoid, ovomucin, conalbumin and ovotransferrin.
10. The method of claim 8 wherein the transcriptional regulatory element is a regulatable promoter.
11. The method of claim 8 wherein the transcriptional regulatory element is a tissue specific promoter.
12. The method of claim 8 wherein the transcriptional regulatory element comprises at least two regions derived from the promoter of an avian gene, the regions being from different promoters.
13. The method of claim 1 wherein the nucleotide sequence comprises at least one cytomegalovirus promoter.
14. The method of claim 1 wherein the nucleotide sequence comprises at least one matrix attachment region (MAR).
15. The method of claim 14 wherein the nucleotide sequence comprises a 5′ MAR and a 3′ MAR which flank the nucleotide sequence.
16. The method of claim 1 wherein the nucleotide sequence is bound to a nuclear localization signal (NLS) peptide during microinjection.
17. The method of claim 1 wherein the heterologous polypeptide is selected from the group consisting of a cytokine, a hormone, an enzyme and an immunolobulin polypeptide.
18. The method of claim 1 wherein the heterologous polypeptide is selected from the group consisting of interferon, interleukin, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, erythropoietin, thrombopoietin and stem cell factor.
19. The method of claim 1 wherein the transgene comprises an internal ribosome entry site (IRES).
20. The method of claim 1 wherein the transgene comprises at least two coding sequences each encoding a heterologous polypeptide.
21. The method of claim 20 wherein the at least two nucleotide sequences encode at least two heterologous peptides that form a multimeric protein.
22. The method of claim 21 wherein the multimeric protein specifically binds a ligand.
23. The method of claim 21 wherein the multimeric protein is an antibody.
24. The method of claim 1 wherein the heterologous polypeptide comprises a peptide region useful for isolation of the heterologous polypeptide.
25. The method of claim 1 wherein the nucleotide sequence comprises a vector.
26. The method of claim 1 wherein the nucleotide sequence comprises a plasmid vector.
27. The method of claim 1 wherein the nucleotide sequence is not a eukaryotic viral vector.
28. The method of claim 1 wherein the transgenic avian is not produce using a eukaryotic viral vector.
29. The method of claim 1 comprising isolating the heterologous peptide from the transgenic avian or from an egg laid by the transgenic avian.
30. A method of producing a transgenic avian comprising:
microinjecting into a cell of an avian embryo a nucleic acid comprising a transgene comprising a nucleotide sequence encoding a pharmaceutical protein;
introducing the microinjected avian embryo into an oviduct of a recipient hen, such that the recipient hen lays a shelled egg containing the microinjected avian embryo;
incubating the shelled egg containing the microinjected avian embryo until the egg hatches;
testing a hatched chick for the presence of the transgene; and
developing a chick that tests positive for the transgene to sexual maturity.
31. The method of claim 1 or 30 wherein the avian is a chicken.
32. The method of claim 30 wherein the coding sequence is expressed in one or more cells of the transgenic avian.
33. The method of claim 30 wherein the heterologous polypeptide is present in the white of an egg produced by the transgenic avian.
34. The method of claim 30 wherein the coding sequence is operably linked to transcriptional regulatory element that can direct gene expression in one or more cells of the transgenic avian.
35. The method of claim 34 wherein the transcriptional regulatory element is a promoter region of an avian gene which encodes a protein selected from the group consisting of ovalbumin, lysozyme, ovomucoid, ovomucin, conalbumin and ovotransferrin.
36. The method of claim 30 wherein the heterologous polypeptide is selected from the group consisting of a cytokine, a hormone, an enzyme, an immunoglobulin polypeptide, interferon, interleukin, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, erythropoietin, thrombopoietin and stem cell factor.
37. The method of claim 30 wherein the transgene comprises at least two coding sequences each encoding a heterologous polypeptide.
38. The method of claim 30 wherein the nucleotide sequence comprises a vector.
39. The method of claim 30 comprising isolating the heterologous peptide from the transgenic avian or from an egg laid by the transgenic avian.
40. A method of producing a transgenic chicken comprising:
microinjecting into a cell of an embryo of a chicken a nucleic acid comprising a transgene comprising a nucleotide sequence encoding a heterologous polypeptide;
introducing the chicken embryo into an oviduct of a recipient chicken, such that the recipient chicken lays a shelled egg containing the microinjected chicken embryo;
incubating the shelled egg containing the microinjected chicken embryo until the egg hatches;
testing a hatched chick for the presence of the transgene; and
developing a chick that tests positive for the transgene to sexual maturity.
41. The method as in any one of claims 1 , 30 or 40 wherein the nucleic acid is DNA.