Transgenic cattle resulting from biopsied embryos: expression of c-ski in a transgenic calf

• Published in: Biology of reproduction Vol. 50; no. 3; pp. 664 - 668
• Main Authors: Bowen, R.A, Reed, M.L, Schnieke, A, Seidel, G.E. Jr, Stacey, A, Thomas, W.K, Kajikawa, O
• Format: Journal Article
• Language: English
• Published: Madison, WI Society for the Study of Reproduction 01.03.1994
• Subjects: ADN; AMPLIFICATION CHAINE POLYMERASE; ANIMAL TRANSGENIQUE; ANIMALES TRANSGENICOS; Animals; Animals, Genetically Modified; ARN MENSAJERO; ARN MESSAGER; Base Sequence; Biological and medical sciences; Biotechnology; Cattle - embryology; Cattle - genetics; Chickens - genetics; EXPRESION GENICA; EXPRESSION DES GENES; Female; Fundamental and applied biological sciences. Psychology; Gene Expression; Gene Transfer Techniques; Genetic engineering; Genetic technics; Male; Methods. Procedures. Technologies; Microinjections; Molecular Sequence Data; Muscles - anatomy & histology; Phenotype; Polymerase Chain Reaction; Pregnancy; REACCION DE CADENAS DE POLIMERASA; Regulatory Sequences, Nucleic Acid; Sarcoma Viruses, Murine - genetics; TERNERO; Transgenic animals; Transgenic animals and transgenic plants; VEAU; Embryo; Genetic marker; Transgenic animal; Ox; Method; Gene expression; Embryo transfer; Vertebrata; Mammalia; Reporter gene; C-Onc gene; Artiodactyla; Detection; Ungulata
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod50.3.664

Producing transgenic cattle by microinjection of DNA into pronuclei has been inefficient and costly, in large part because of the cost of maintaining numerous nontransgenic pregnancies to term. We designed a system for early identification of transgenic embryos in which biopsies of embryos were assayed by polymerase chain reaction for presence of the transgene before embryo transfer. A total of 2555 embryos were microinjected with one of two DNA constructs. Of the 533 embryos biopsied, 112 were judged to be potentially transgenic and were transferred nonsurgically to recipients, resulting in production of 29 putative transgenic fetuses. One fetus and one calf (7% of offspring) were subsequently shown to be definitively transgenic. The calf was transgenic for a chicken c-ski cDNA, and several months after birth developed dramatic muscular hypertrophy followed by muscle degeneration. This phenotype was associated with expression of high levels of mRNA from the transgene