Multicellular living organisms and unmodified parts thereof and – Method of making a transgenic nonhuman animal – Via microinjection of a nucleus into an embryo – egg cell – or...
Reexamination Certificate
2000-12-28
2004-03-02
Crouch, Deborah (Department: 1632)
Multicellular living organisms and unmodified parts thereof and
Method of making a transgenic nonhuman animal
Via microinjection of a nucleus into an embryo, egg cell, or...
C800S008000, C800S017000
Reexamination Certificate
active
06700037
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to the cloning of porcine animals.
BACKGROUND OF THE INVENTION
The following discussion of the background of the invention is merely provided to aid the reader in understanding the invention and is not admitted to describe or constitute prior art to the present invention.
Researchers have been developing methods for cloning mammalian animals over the past two decades. Some reported methods include the steps of (1) isolating a cell, most often an embryonic cell; (2) inserting that cell or a nucleus isolated from the cell into an enucleated oocyte (e.g., the nucleus of the oocyte was previously extracted), and (3) allowing the embryo to mature in vivo.
The first successful nuclear transfer experiment using mammalian cells was reported in 1983, where pronuclei isolated from a murine (mouse) zygote were inserted into an enucleated oocyte and resulted in live offspring(s). McGrath & Solter, 1983,
Science
220:1300-1302. Subsequently, others described the production of chimeric murine embryos (e.g., embryos that contain a subset of cells having significantly different nuclear DNA from other cells in the embryo) using murine primordial germ cells (PGCs). These cells are and can give rise to pluripotent cells. Matsui et al., 1992,
Cell
70:841-847 and Resnick et al., 1992, Nature 359:550; Kato et al., 1994,
Journal of Reproduction and Fertility
Abstract Series, Society For the Study of Fertility, Annual Conference, Southampton, 13:38. In 1998, researchers reported that murine cumulus cells can be used as nuclear donors in cloning techniques for establishing cloned murine animals. Wakayama et al., 1998,
Nature
394: 369-374.
Another nuclear transfer experiment was reported in 1986, where an ovine (sheep) embryonic cell was used as a nuclear donor in a cloning process that resulted in a cloned lamb. Willadsen, 1986,
Nature
320:63-65. More recently, other lambs were reported to be cloned from ovine embryonic cells; serum deprived somatic cells; cells isolated from embryonic discs; and somatic mammary tissue. Campbell et al., 1996,
Nature
380:64-66; PCT Publication WO 95/20042; Wilmut et al., 1997,
Nature
385:810-813; and PCT Publications WO 96/07732 and WO 97/07669. Other approaches for cloning ovine animals involved manipulating the activation state of an in vivo matured oocyte after nuclear transfer. PCT Publication WO 97/07668. Publications that disclose cloned lambs report a cloning efficiency that is, at best, approximately 0.4%. Cloning efficiency, as calculated for the previous estimate, is a ratio equal to the number of cloned lambs divided by the number of nuclear transfers used to produce that number of cloned lambs.
Yet another nuclear transfer experiment resulted in a cloned bovine animal (cattle), where the animal was cloned using an embryonic cell derived from a 2-64 cell embryo as a nuclear donor. This bovine animal was reportedly cloned by utilizing nuclear transfer techniques set forth in U.S. Pat. Nos. 4,994,384 and 5,057,420. Others reported that cloned bovine embryos were formed where an inner cell mass cell of a blastocyst stage embryo was utilized as a nuclear donor in a nuclear transfer procedure. Sims & First, 1993,
Theriogenology
39:313 and Keefer et al., 1994,
Mol. Reprod. Dev.
38:264-268. In addition, another publication reported that cloned bovine embryos were prepared by nuclear transfer techniques that utilized a PGC isolated from fetal tissue as a nuclear donor. Delhaise et al., 1995,
Reprod. Fert. Develop.
7:1217-1219; Lavoir 1994,
J. Reprod. Dev.
37:413-424; and PCT application WO 95/10599 entitled “Embryonic Stem Cell-Like Cells.”
With regard to porcine animals (swine), researchers have reported methods for obtaining chimeric animals, and cloned animals. See., e.g., Prather et al., 1989,
Biology of Reproduction
41: 414-418; Piedrahita et al., 1998,
Biology of Reproduction
58: 1321-1329; and WO 94/26884, “Embryonic Stem Cells for Making Chimeric and Transgenic Ungulates,” Wheeler, published Nov. 24, 1994.
Also, researchers have reported nuclear transfer experiments using porcine nuclear donors and porcine oocytes. See., e.g., Nagashima et al., 1997,
Mol. Reprod. Dev.
48: 339-343; Nagashima et al., 1992, J. Reprod. Dev. 38: 73-78; Prather et al., 1989,
Biol. Reprod.
41: 414-419; Prather et al., 1990,
Exp. Zool.
255: 355-358; Saito et al., 1992,
Assis. Reprod. Tech. Andro.
259: 257-266; Terlouw et al., 1992,
Theriogenology
37: 309, Pokajaeva et al.,
Nature
407, 86-90 (2000); Onishi et al.,
Science
289 1188-1190 (2000); and Betthauser et al.,
Nature Biotechnology
18: 1055-1059 (2000).
In addition, researchers have reported methods for activating porcine oocytes. Grocholo{acute over (v)}a et al., 1997,
J. Exp. Zoology
277: 49-56; Schoenbeck et al., 1993,
Theriogenology
40: 257-266; Prather et al., 1991,
Molecular Reproduction and Development
28: 405-409; Jolliff & Prather, 1997,
Biol. Reprod.
56: 544-548; Mattioli et al., 1991,
Molecular Reproduction and Development
30: 109-125; Terlouw et al., 1992,
Theriogenology
37: 309; Prochazka et al., 1992,
J. Reprod. Fert.
96: 725-734; Funahashi et al., 1993, Molecular Reproduction and Development 36: 361-367; Prather et al.,
Bio. Rep.
Vol. 50 Sup 1: 282; Nussbaum et al., 1995,
Molecular Reproduction and Development
41: 70-75; Funahashi et al., 1995,
Zygote
3: 273-281; Wang et al., 1997,
Biology of Reproduction
56: 1376-1382; Piedrahita et al., 1989,
Biology of Reproduction
58: 1321-1329; Machaty et al., 1997,
Biology of Reproduction
57: 85-91; and Macháty et al., 1995,
Biology of Reproduction
52: 753-758.
There remains a long felt need for materials and methods that yield efficient nuclear transfer using a porcine nuclear donor. This long felt need is based in part upon a potential medical application, known as xenotransplantation, which includes procedures for extracting organs from porcine animals and transplanting these organs into humans in need of such organs. U.S. Pat. No. 5,589,582, Hawley et al., issued Dec. 31, 1991; PCT application WO 95/28412, Baetsher et al., published Oct. 26, 1995; PCT application WO 96/06165, Sachs et al., published Feb. 29, 1996; PCT application WO 93/16729, Bazin, published Sep. 2, 1993; PCT application WO 97/12035, Diamond et al., published Apr. 3, 1997; PCT application WO 98/16630, Piedrahita & Bazer, published Apr. 23, 1998.
SUMMARY
The invention relates in part to cloning technologies for porcine animals. The invention also relates in part to totipotent cells and cells that can be made totipotent, for use in cloning procedures and production of porcine animals, embryos produced from these porcine cells using nuclear transfer techniques, porcine animals that arise from these cells and embryos, and methods and processes for establishing such cells, embryos, and animals.
The present invention provides multiple advantages over tools and methods currently utilized for porcine cloning. Such features and advantages include:
(1) Production of cloned porcine animals from virtually any type of cell. The invention provides materials and methods for reprogramming non-totipotent porcine cells into totipotent porcine cells. These non-totipotent porcine cells may be of non-embryonic origin. This feature of the invention allows for an ability to assess a phenotype of an existing porcine animal and then readily establish a totipotent cell line for cloning that animal.
(2) Establishment of totipotent porcine cell lines from virtually any type of porcine cell. In one aspect of the invention, non-totipotent porcine precursor cells can be reprogrammed into totipotent cells. These non-totipotent precursor cells may be non-embryonic cells. Established totipotent porcine cell lines provide an advantage of enhancing cloning efficiency due to lower cellular heterogeneity within cell lines. In addition, the totipotent cell lines can be manipulated in vitro to produce porcine cells, embryos, and animals whose genomes have been manipulated (e.g., transgenic).
(3) Efficiency enhancement for cloning
Betthauser Jeffrey M.
Bishop Michael D.
Damiani Philip
Forsberg Erik J.
Crouch Deborah
Foley & Lardner
Infigen, Inc.
Ton Thai-An N.
Warburg Richard J.
LandOfFree
Method of cloning porcine animals does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of cloning porcine animals, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of cloning porcine animals will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3242437