Hostname: page-component-5c6d5d7d68-wtssw Total loading time: 0 Render date: 2024-08-22T00:44:33.992Z Has data issue: false hasContentIssue false

Altering nutrient utilization in animals through transgenesis

Published online by Cambridge University Press:  14 December 2007

Kevin A Ward*
Affiliation:
Commonwealth Scientific and Industrial Research Organization (CSIRO) Animal Production, Locked Bag 1, Delivery Center, Blacktown, NSW 2148, Australia
*
Corresponding author: Dr Kevin A. Ward, fax +61 298 402940, email kevin@nugget.prospect.anprod.csiro.au
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Improved domestic animal productivity is necessary in order to provide for an increasing world population over the next two to three decades and such improvement would be aided by an increase in the efficiency of nutrient utilization. This can be achieved by conventional genetic selection protocols but progress by this approach is slow. A more rapid but as yet largely unproven technique is the direct modification of the genome which can be achieved by the transfer of recombinant DNA to the nuclei of early embryos. This new technology is potentially powerful because it allows the direct transfer of genes without regard to inter-species barriers to breeding. However, it raises a new set of problems associated with the integration and expression of the foreign genetic information in the new genome. In this review the application of the technology to increasing nutrient utilization and increased productivity are discussed. Two areas have received substantial attention in the 15 years since the technique was first applied to domestic animals. First, the current status of the modification of growth hormone levels to improve productivity and feed utilization efficiency is reviewed, with current results suggesting that several of the projects may soon be approaching field trial status. Second, the introduction of novel biochemical pathways to domestic animals to provide them with different sources of the substrates required for growth and production is discussed. Recent results obtained in the introduction of a cysteine biosynthetic pathway to animals is reviewed. While this line of research remains some distance from commercial application, it provides a useful example of the powerful possibilities inherent in the new technology. However, it also serves to highlight some of the difficulties that might be expected as new genes are expressed to produce enzymes that must fit compatibly with existing animal biochemistry.

Type
Research Article
Copyright
Copyright © CABI Publishing 1999

References

Ali, S, Hall, J, Soole, KL, Fontes, CMGA, Hazlewood, GP, Hirst, BH, Gilbert, HJ (1995) Targeted Expression of Microbial Cellulases in Transgenic Animals. Carbohydrate Bioengineering. Proceedings of an International Conference, Elsinore, Denmark, 23–26 April, 1995, pp. 279293 [Petersen, SB, Svensson, B, and Pedersen, S, editors]. Amsterdam, The Netherlands: Elsevier Science Publishers.Google Scholar
Bawden, CS, Sivaprasad, AV, Verma, SK, Walker, SK, Rogers, GE (1995) Expression of bacterial cysteine biosynthesis genes in transgenic mice and sheep: toward a new in vivo amino acid biosynthesis pathway and improved wool growth. Transgenic Research 4, 87104.CrossRefGoogle Scholar
Bergman, EN (1975) Production and utilization of metabolites by the alimentary tract as measured in portal and hepatic blood. In Digestion and Metabolism in the Ruminant, pp. 292305 [McDonald, IW, and Warner, ACI, editors]. Armidale, Australia: The University of New England Publishing Unit.Google Scholar
Bosselman, RA, Hsu, R-Y, Boggs, T, Hu, S, Bruszewski, J, Ou, S, Kozar, L, Martin, F, Green, C (1989) Germline transmission of exogenous genes in the chicken. Science 243, 533535.CrossRefGoogle ScholarPubMed
Brackett, BG, Boranska, W, Sawicki, W & Koprowski, H (1971) Uptake of heterologous genome by mammalian spermatozoa and its transfer to ova through fertilization. Proceedings of the National Academy of Sciences, USA 68, 353357.CrossRefGoogle ScholarPubMed
Bray, AC & Till, AR (1975) Metabolism of sulphur in the gastro-intestinal tract. In Digestion and Metabolism in the Ruminant, pp. 243260 [McDonald, IW and Warner, ACI, editors]. Armidale, Australia: The University of New England Publishing Unit.Google Scholar
Brem, G, Brenig, B, Goodman, RC, Selden, RC, Graf, F, Kruff, K, Springman, J, Hondele, J, Meyer, E-L, Winnacker, EL & Krausslich, H (1985) Production of transgenic mice, rabbits and pigs by microinjection into pronuclei. Zuchthygiene 20, 251252.Google Scholar
Brinster, RL, Chen, HY, Trumbauer, ME, Yagle, MK & Palmiter, RD (1985) Factors affecting the efficiency of introducing foreign DNA into mice by microinjecting eggs. Proceedings of the National Academy of Sciences, USA 82, 44384442.CrossRefGoogle ScholarPubMed
Brinster, RL, Sandgren, EP, Behringer, RR & Palmiter, RD (1989) No simple solution for making transgenic mice. Cell 59, 239241.CrossRefGoogle ScholarPubMed
Brown, LR (1997) Facing the prospect of food scarcity. In State of the World 1997, pp. 2341 [Brown, LR, Abramovitz, JN, Bright, C, Flavin, C, French, HF, Gardner, G, McGinn, AP, Renner, M, Roodman, DM and Starke, L, editors]. London: Earthscan Publications Ltd.Google Scholar
Byrne, CR (1990) The isolation of bacterial acetate metabolism genes and their expression in a eukaryote. PhD Thesis. Macquarie University, Sydney, Australia.Google Scholar
Byrne, CR, Monroe, RS, Ward, KA & Kredich, NM (1988) DNA sequences of the csyK regions of S. typhimurium and E. coli and linkage of the cysK regions to ptsH. Journal of Bacteriology 170, 31503157.CrossRefGoogle Scholar
Campbell, KHS, McWhir, J, Ritchie, KA & Wilmut, I (1996) Sheep cloned by nuclear transfer from a cultured cell line. Nature 380, 6466.CrossRefGoogle ScholarPubMed
Campbell, RG, Steele, NC, Caperna, TJ, McMurtry, JP, Solomon, MB & Mitchell, AD (1988) Inter-relationships between energy intake and endogenous porcine growth hormone administration on the performance, body composition, and protein and energy metabolism of growing pigs weighing 25 to 55 kilograms live weight. Journal of Animal Science 66, 16431655.CrossRefGoogle Scholar
Chan, AWS, Homan, EJ, Ballou, LU, Burns, JC & Bremel, RD (1998) Transgenic cattle produced by reverse-transcribed gene transfer in oocytes. Proceedings of the National Academy of Sciences, USA 95, 1402814033.CrossRefGoogle ScholarPubMed
Chapman, RE & Ward, KA (1979) Histological and biochemical features of the wool fibre and follicle. In Physiological and Environmental Limitations to Wool Growth, pp. 193208 [Black, JL and Reis, PJ, editors]. Armidale, Australia: University of New England Publishing Unit.Google Scholar
Cibelli, JB, Stice, SL, Golueke, PJ, Kane, JJ, Jerry, J, Blackwell, C, Ponce, deLeon, FA & Robl, JM (1998) Cloned transgenic calves produced from nonquiescent fetal fibroblasts. Science 280, 12561258.CrossRefGoogle ScholarPubMed
Denk, D & Bock, A (1987) L-cysteine biosynthesis in Escherichia coli: nucleotide sequence and expression of the serine acetyltransferase (cysE) gene from the wild-type and a cysteine-excreting mutant. Journal of General Microbiology 133, 515525.Google Scholar
Devlin, RH, Yesaki, TY, Donaldson, EM, ShaoJun, Du, Hew, ChoyLeong, Du, SJ & Hew, CL (1995) Production of germline transgenic Pacific salmonids with dramatically increased growth performance. Canadian Journal of Fisheries and Aquatic Sciences 52, 13761384.CrossRefGoogle Scholar
Draghia-Akli, R, Li, X & Schwartz, RJ (1997) Enhanced growth by ectopic expression of growth hormone releasing hormone using an injectable myogenic vector. Nature Biotechnology 15, 12851294.CrossRefGoogle ScholarPubMed
Du, SJ, Gong, Z, Fletcher, GL, Shears, MA, Hooper, ML, Melton, W, Thomson, S & Smithies, O (1992) Growth enhancement in transgenic Atlantic salmon by the use of an all fish chimeric growth hormone gene construct. Biotechnology 10, 176181.Google ScholarPubMed
Dunham, RA & Devlin, RH (1998) Comparison of traditional and molecular approaches to genetic improvement in catfish and carp. In Transgenic Animals in Agriculture, pp. 209229 [Murray, JD, Anderson, GB, McGloughlin, MM and Oberbauer, AM, editors]. Wallingford, Oxon.: CAB International.Google Scholar
Ebert, KM, Low, MJ, Overstrom, EW, Buonoma, FC, Roberts, TM, Lee, E, Mandel, G & Goodman, RC (1988) A Moloney MLV-rat somatotropin fusion gene produces biologically active somatotropin in a transgenic pig. Endocrinology 2, 277283.Google Scholar
Ebert, KM, Smith, TE, Buonoma, FC, Overstrom, EW & Low, MJ (1990) Porcine growth hormone gene expression from viral promoters in transgenic swine. Animal Biotechnology 1, 145159.CrossRefGoogle Scholar
Entis, E (1997) AquaAdvantage salmon: issues in the introduction of transgenic foods. Kungliga Skogs-och Lantbruksakademiens Tidskrift 136, 127131.Google Scholar
Evock, CM, Etherton, TD, Chung, CS & Ivy, RE (1988) Pituitary porcine growth hormone (pGH) and a recombinant pGH analog stimulate pig growth performance in a similar manner. Journal of Animal Science 66, 19281941.CrossRefGoogle Scholar
Federoff, NE, Botstein, DE & McClintock, B (1992) The Dynamic Genome: Barbara McClintock's Ideas in the Century of Genetics. New York: Cold Spring Harbor Laboratory Press.Google Scholar
Florini, JR (1998) Hormonal control of muscle cell growth. Journal of Animal Science 61, Suppl. 2. 2138.CrossRefGoogle Scholar
Forsberg, CW, Cheng, KJ, Krell, PJ & Phillips, JP (1993) Proceedings 7th World Congress on Animal Production vol. 1, 281316.Google Scholar
Fu, C, Cui, Y, Hung, SSO & Zhu, Z (1998) Growth and feed utilization by F4 human growth hormone transgenic carp fed diets with different protein levels. Journal of Fish Biology 53, 115129.Google Scholar
Gelinas, C & Temin, HM (1986) Nondefective spleen necrosis virus-derived vectors define the upper size limit for packaging reticuloendotheliosis viruses. Proceedings of the National Academy of Sciences, USA 83, 92119215.CrossRefGoogle ScholarPubMed
Goodband, RD, Nelssen, JL, Hines, RH, Kropf, DH, Thaler, RC, Schricker, BR & Fitzner, GE (1988) The effect of porcine somatotropin (PST) and dietary lysine level on growth performance and carcass characteristics of finishing swine. Journal of Animal Science 66, Suppl 1. 95.Google Scholar
Hackett, PB, Izsvak, Z, Ivics, Z & Caldovic, L (1998) Development of genetic tools for transgenic fish. In Transgenic Animals in Agriculture, pp. 1935 [Murray, JD, Anderson, GB, McGloughlin, MM and Oberbauer, AM, editors]. Wallingford, Oxon.: CAB International.Google Scholar
Hall, J, Ali, S, Azim Surani, M, Hazlewood, GP, Clark, AJ, Simons, JP, Hirst, BH & Gilbert, HJ (1993) Manipulation of the repertoire of digestive enzymes secreted into the gastrointestinal tract of transgenic mice. Biotechnology 11, 376379.CrossRefGoogle ScholarPubMed
Hall, J, Barker, P, Hazlewood, GP & Gilbert, HJ (1988) Conserved reiterated domains in Clostridium thermocellum endoglucanases are not essential for catalytic activity. Gene 69, 2938.CrossRefGoogle Scholar
Hall, J, Hazlewood, GP, Azim Surani, M, Hirst, BH & Gilbert, HJ (1990) Eukaryotic and prokaryotic signal peptides direct secretion of a bacterial endoglucanase by mammalian cells. Journal of Biological Chemistry 265, 1999619999.CrossRefGoogle ScholarPubMed
Hammer, RE, Pursel, VG, Rexroad, CE, Wall, RJ, Bolt, DJ, Ebert, KM, Palmiter, RD & Brinster, RL (1985) Production of transgenic rabbits, sheep and pigs by microinjection. Nature 315, 680683.CrossRefGoogle ScholarPubMed
Hazlewood, G, Mann, S & Gilbert, H (1989) Improving forage digestion by genetic engineering. AFRC News 1213.Google Scholar
Hofman, A, Nolan, GP & Blau, HM (1996) Rapid retroviral delivery of tetracycline-inducible genes in a single autoregulatory cassette. Proceedings of the National Academy of Sciences, USA 93, 51855190.CrossRefGoogle Scholar
Jaenisch, R (1988) Transgenic animals. Science 240, 14681474.CrossRefGoogle ScholarPubMed
Johnson, ID, Hart, ICb & Butler-Hogg, BW (1985) The effects of exogenous bovine growth hormone and bromocryptine on growth, body development, fleece weight and plasma concentrations of growth hormone, insulin and prolactin in female lambs. Animal Production 41, 207217.Google Scholar
Karapetiyan, RV (1997) Transgenic chickens produced by microinjecting DNA into the ovum. Russian Agricultural Sciences 3, 3437.Google Scholar
Kerr, DE, Furth, PA, Powell, AM & Wall, RJ (1996) Expression of the gene-gun injected plasmid DNA in the ovine mammary gland and in lymph nodes draining the injection site. Animal Biotechnology 7, 3345.CrossRefGoogle Scholar
Kim, DG, Kang, HM, Jang, SK & Shin, HS (1992) Construction of a bifunctional mRNA in the mouse by using the internal ribosomal entry site of the encephalomyocarditis virus. Molecular and Cellular Biology 12, 36363643.Google ScholarPubMed
Lavitrano, M, Camaloni, A, Fazio, VM, Dolci, S, Farace, MG & Spadafora, C (1989) Sperm cells as vectors for introducing foreign DNA into eggs: genetic transformation of mice. Cell 57, 717723.CrossRefGoogle ScholarPubMed
Leish, Z, Byrne, CR, Hunt, CL & Ward, KA (1993) Introduction and expression of the bacterial genes cysE and cysK in eukaryotic cells. Applied Environmental Microbiology 59, 892898.CrossRefGoogle ScholarPubMed
Lindsay, D (1998) The Australian livestock industries: a case study in non-genetic factors that control genetic improvement. Proceedings of 6th World Congress on Genetics Applied to Livestock Production, vol. 23, pp. 39. Armidale, Australia: World Congress.Google Scholar
Maclean, N, Penman, D, Talwar, S & Tiews, K (1987) Introduction of novel genes into the rainbow trout. Heenemann Verlagsgesellschaft mBH, vol. 2, pp. 325333. Berlin: German Federal Republic.Google Scholar
Martinez, R, Estrada, MP, Berlanga, J, Guillen, I, Hernandez, O, Cabrera, E, Pimentel, R, Morales, R, Herrera, F, Morales, A, Pina, JC, Abad, Z, Sanchez, V, Melamed, P, Lleonart, R & de la Fuente, J (1996) Growth enhancement in transgenic Tilapia by ectopic expression of Tilapia growth hormone. Molecular Marine Biology and Biotechnology 5, 6270.Google ScholarPubMed
Mather, C, Love, J, Gribbina, C & Sang, H (1994) The production of transgenic chickens by means of microinjected DNA. Zootecnica International 17, 52.Google Scholar
Muir, LA, Wien, S, Duquette, PF, Rickes, EL & Cordes, EH (1983) Effects of exogenous growth hormone and diethylstilbestrol on growth and carcass composition of growing lambs. Journal of Animal Science 56, 13151323.CrossRefGoogle ScholarPubMed
Murray, JD, Nancarrow, CD, Marshall, JT, Hazelton, IG & Ward, KA (1989) Production of transgenic sheep by microinjection of ovine metallothionein-ovine growth hormone fusion genes. Reproduction, Fertility and Development 1, 147155.CrossRefGoogle ScholarPubMed
Nancarrow, CD, Marshall, JTA, Clarkson, JL, Murray, JD, Millard, RM, Shanahan, CM, Wynn, PC & Ward, KA (1991) Expression and physiology of performance regulating genes in transgenic sheep. Journal of Reproduction and Fertility 43, Suppl., 277291.Google ScholarPubMed
Newcomb, MD, Grebner, GL, Bechtel, PJ, McKeith, FK, Novakofski, J, McLaren, DG & Easter, RA (1988) Response of 60 to 100 kg pigs treated with porcine somatotrophin to different levels of dietary crude protein. Journal of Animal Science 66, Suppl., 281.Google Scholar
Nottle, MB, Nagashima, H, Verma, PJ, Du, ZT, Grupen, CG, MacIlfatrick, SM, Ashman, RJ, Harding, MP, Glannakis, C, Wigley, PL, Lyons, IG, Harrison, DT, Luxford, BG, Campbell, RG, Crawford, RJ & Robins, AJ (1998) Production and elevation of growth hormone transgenic pigs. In Transgenic Animals in Agriculture, pp. 145156 [Murray, JD, Anderson, GB, McGloughlin, MM and Oberbauer, AM, editors]. Wallingford, Oxon.: CAB International.Google Scholar
Palmiter, RD & Brinster, RL (1986) Germline transformation of mice. Annual Review of Genetics 20, 465500.CrossRefGoogle ScholarPubMed
Palmiter, RD, Brinster, RL, Hammer, RE, Trumbauer, ME, Rosenfeld, MG, Birnberg, NC & Evans, RM (1982) Dramatic growth of mice that develop from eggs microinjected with metallothionein-growth hormone GH fusion genes. Nature 300, 611615.CrossRefGoogle Scholar
Palmiter, RD, Norstedt, RE, Gelinas, RE, Hammer, RE & Brinster, RL (1983) Metallothionein-human GH fusion genes stimulate growth in mice. Science 222, 809814.CrossRefGoogle Scholar
Perry, MM & Sang, H (1993) Transgenesis in chickens. Transgenic Research 2, 125133.CrossRefGoogle ScholarPubMed
Pursel, VG, Coleman, ME, Wall, RJ, Elsasser, TH & Haden, M (1996) Regulatory avian skeletal alpha-actin directs expression of insulin-like growth factor-1 to skeletal muscle of transgenic pigs. Theriogenology 45, Suppl., 348.CrossRefGoogle Scholar
Pursel, VG, Hammer, RE, Bolt, DJ, Palmiter, RD & Brinster, RL (1990) Genetic engineering of swine: integration, expression and germline transmission of growth-related genes. Journal of Reproduction and Fertility 41, 7787.Google Scholar
Pursel, VG, Miller, KF, Bolt, DJ, Pinkert, CA, Hammer, RE, Palmiter, RD & Brinster, RL (1989) Insertion of growth hormone genes into pig embryos. In Biotechnology of Growth Regulation, pp. 181188 [Heap, RB, Prosser, CG and Lamming, GE, editors]. London: Butterworths.CrossRefGoogle Scholar
Pursel, VG, Pinkert, CA, Miller, KF, Bolt, DJ, Campbell, RG, Palmiter, RD, Brinster, RL & Hammer, RE (1989) Genetic engineering of livestock. Science 244, 1281.CrossRefGoogle ScholarPubMed
Pursel, VG, Rexroad, CE, Bolt, DJ, Miller, KF, Wall, RJ, Hammer, RE, Pinkert, CA, Palmiter, RD & Brinster, RL (1987) Progress on gene transfer in farm animals. Veterinary Immunology and Histopathology 17, 303312.CrossRefGoogle ScholarPubMed
Pursel, VG & Solomon, MB (1993) Alteration of carcass composition in transgenic swine. Food Reviews International 9, 423439.CrossRefGoogle Scholar
Pursel, VG, Wall, RJ, Mitchell, AD, Elsasser, TH, Solomon, MB, Coleman, ME, DeMayo, F & Schwartz, RJ (1998) Expression of insulin-like growth factor-1 in skeletal muscle of transgenic swine. In Transgenic Animals in Agriculture, pp. 131144 [Murray, JD, Anderson, GB, McGloughlin, MM and Oberbauer, AM, editors]. Wallingford, Oxon.: CAB International.Google Scholar
Pursel, VG, Wall, RJ, Solomon, MB, Bolt, DJ, Murray, JD & Ward, KA (1997) Transfer of ovine metallothionein-ovine growth hormone fusion gene into swine. Journal of Animal Science 75, 22082214.CrossRefGoogle ScholarPubMed
Rees, WD, Flint, HJ & Fuller, MF (1990) A molecular biological approach to reducing dietary amino acid needs. Biotechnology 8, 629633.Google ScholarPubMed
Reis, PJ (1979) Effect of amino acids on the growth and properties of wool. In Physiological and Environmental Limitations to Wool Growth, pp. 223242 [Black, JL and Reis, PJ, editors]. Armidale, Australia: University of New England Publishing Unit.Google Scholar
Rexroad, CE Jr, Behringer, RR, Bolt, DJ, Miller, KF, Palmiter, RD & Brinster, RL (1988) Insertion and expression of a growth hormone fusion gene in sheep. Journal of Animal Science 6, 267.Google Scholar
Rexroad, CE Jr, Hammer, RE, Behringer, RR, Palmiter, RD & Brinster, RL (1990) Insertion, expression and physiology of growth-regulating genes in ruminants. Journal of Reproduction and Fertility Suppl. 41, 119124.Google ScholarPubMed
Rieger, D & Guay, P (1988) Measurement of the metabolism of energy substrates in individual bovine blastocysts. Journal of Reproduction and Fertility 83, 585591.CrossRefGoogle Scholar
Robinson, CR & Sauer, RT (1998) Optimizing the stability of single-chain proteins by linker length and composition mutagenesis. Proceedings of the National Academy of Sciences, USA 95, 59295934.CrossRefGoogle ScholarPubMed
Saini, KS, Byrne, CR, Leish, Z, Pruss, CA, Rigby, NW, Brownlee, AG, Nancarrow, CD & Ward, KA (1996) Introduction and expression of the bacterial glyoxylate cycle genes in transgenic mice. Transgenic Research 5, 467473.CrossRefGoogle ScholarPubMed
Sang, H (1994) Transgenic chickens - methods and potential applications. Trends in Biotechnology 12, 415420.CrossRefGoogle ScholarPubMed
Saunders, RL, Fletcher, GL, Hew, CL, Bromage, N, Soivio, A, Bjornsson, BP & Eriksson, LO (1998) Smolt development in growth hormone transgenic Atlantic salmon. Aquaculture 168, 177193.CrossRefGoogle Scholar
Sejrsen, K (1986) Endocrine mechanisms underlying genetic variation in growth in ruminants. In Proceedings of the 3rd World Congress on Animal Genetics Applied to Animal Production, vol. 11, pp. 261270. Lincoln, NE: University of Nebraska.Google Scholar
Shanahan, CM, Rigby, NW, Murray, JD, Marshall, J, Townrow, C, Nancarrow, CD & Ward, KA (1989) Regulation of expression of a sheep growth hormone fusion gene in transgenic mice. Molecular and Cellular Biology 9, 54735479.Google ScholarPubMed
Sherman, A, Dawson, A, Mather, C, Gilhooley, H, Ying, Li, Mitchell, R, Finnegan, D & Sang, H (1998) Transposition of the Drosophila element mariner into the chicken germ line. Nature Biotechnology 16, 10501053.CrossRefGoogle ScholarPubMed
Sherratt, DJ (1995) Mobile Genetic Elements, Oxford, Oxon.: IRL Press, Ltd.CrossRefGoogle Scholar
Sivaprasad, AV, Kuczek, ES, Bawden, CS & Rogers, GE (1992) Coexpression of the cysE and cysM genes of Salmonella typhimurium in mammalian cells: a step towards establishing cysteine biosynthesis in sheep by transgenesis. Transgenic Research 1, 7992.CrossRefGoogle Scholar
Soole, KL, Hirst, BH, Hazlewood, GP, Gilbert, HJ, Laurie, JL & Hall, J (1993) Secretion of a prokaryotic cellulase in bacterial and mammalian cells. Gene 125, 8589.CrossRefGoogle ScholarPubMed
Speksnijder, GJ, Etches, RJ & Gibbins, AMV (1999) Molecular Reproduction and Development 52, 3342.3.0.CO;2-G>CrossRefGoogle Scholar
Spencer, GSG (1985) Hormonal systems regulating growth: A review. Livestock Production Science 12, 3146.CrossRefGoogle Scholar
Sperandio, S, Lulli, V, Bacci, ML, Forni, M, Maione, B, Spadafora, C & Lavitrano, M (1996) Sperm-mediated DNA transfer in bovine and swine species. Animal Biotechnology 7, 5977.CrossRefGoogle Scholar
Stewart, CL, Schuetze, S, Vanek, M & Wagner, EF (1987) Expression of retroviral vectors in transgenic mice obtained by embryo infection. EMBO Journal 6, 383388.CrossRefGoogle ScholarPubMed
Tribe, DE (1998) How Sapiens is Homo? Proceedings of 6th World Congress on Genetics Applied to Livestock Production, vol. 23, pp. 1015. Armidale, Australia: World Congress.Google Scholar
Valerio, D (1992) Retrovirus vectors for gene therapy procedures. In Transgenic Animals, pp. 211246 [Grosveld, F and Kollias, G, editors]. London: Academic Press.Google Scholar
Van Soest, PJ (1982) Nutritional Ecology of the Ruminant. Portland, OR: Durham and Downey.Google Scholar
Vize, PD, Mickalska, AE, Ashman, R, Lloyd, B, Stone, BA, Quinn, P, Wells, JRE & Seamark, RF (1988) Introduction of a porcine growth hormone fusion gene into transgenic pigs promotes growth. Journal of Cell Science 90, 295300.CrossRefGoogle ScholarPubMed
von Bodman, SB, Domier, LL & Farrand, SK (1995) Expression of multiple eukaryotic genes from a single promoter in Nicotiana. Biotechnology 13, 587591.Google ScholarPubMed
Wagner, JF & Veenhuizen, EL (1988) Growth performance, carcass deposition and plasma hormone levels in wether lambs when treated with growth hormone and thyroprotein. Journal of Animal Science 47, Suppl. 1397.Google Scholar
Wakayama, T, Perry, ACF, Zuccotti, M, Johnson, KR & Yanagimachi, R (1998) Full-term development of mice from enucleated oocytes injected with cumulus cell nuclei. Nature 394, 369374.CrossRefGoogle ScholarPubMed
Wall, RJ (1996) Transgenic livestock: progress and prospects for the future. Theriogenology 45, 5768.CrossRefGoogle Scholar
Ward, KA & Brown, BW (1999) The production of transgenic domestic livestock: successes, failures and the need for nuclear transfer. Reproduction, Fertility and Development (In the Press)Google Scholar
Ward, KA, Leish, Z, Bonsing, J, Nishimura, N, Cam, GR, Brownlee, AG & Nancarrow, CD (1994) Preventing hairloss in mice. Nature 371, 563564.CrossRefGoogle Scholar
Ward, KA, Leish, Z, Brownlee, AG, Nancarrow, CD & Brown, BW (1998) The utilization of bacterial genes to modify domestic animal biochemistry. In Transgenic Animals in Agriculture, pp. 157176 [Murray, JD, Anderson, GB, McGloughlin, MM and Oberbauer, AM, editors]. Wallingford, Oxon.: CAB International.Google Scholar
Ward, KA & Nancarrow, CD (1991) The genetic engineering of production traits in domestic animals. Experientia 47, 913922.CrossRefGoogle ScholarPubMed
Ward, KA, Nancarrow, CD, Murray, JD, Wynn, PC, Speck, P & Hales, JRS (1989) The physiological consequences of growth hormone fusion gene expression in transgenic sheep. Journal of Cellular Biochemistry 13, 164.Google Scholar
Waugh, EE & Wales, RG (1993) Oxidative utilization of glucose, acetate and lactate by early implantation sheep, mouse and cattle embryos. Reproduction, Fertility and Development 5, 123133.CrossRefGoogle Scholar
Wieghart, M, Hoover, JL, McCrane, MM, Hanson, RW, Rottman, FM, Holtzman, SH, Wagner, TE & Pinkert, CA (1990) Production of transgenic pigs harbouring a rat phosphoenolpyruvate carboxykinase-bovine growth hormone fusion gene. Journal of Reproduction and Fertility Suppl. 41, 8996.Google ScholarPubMed
Wigler, M, Pellicer, A, Silverstein, S, Axel, R, Urlaub, G & Chasin, L (1979) DNA-mediated transfer of the adenine phosphoribosyltransferase locus into mammalian cells. Proceedings of the National Academy of Sciences, USA 76, 13731376.CrossRefGoogle ScholarPubMed
Willadsen, SM (1986) Nuclear transplantation in sheep embryos. Nature 320, 6365.CrossRefGoogle ScholarPubMed
Williams, RS, Johnston, SA, Riedy, M, DeVit, MJ, McElligott, SG & Sanford, JC (1991) Introduction of foreign genes into tissues of living mice by DNA-coated microprojectiles. Proceedings of the National Academy of Sciences, USA 88, 27262730.CrossRefGoogle ScholarPubMed
Wilmut, I, Schnieke, AE, McWhir, J, Kind, AJ & Campbell, KHS (1997) Viable offspring derived from fetal and adult mammalian cells. Nature 385, 810813.CrossRefGoogle ScholarPubMed