Transgenic cattle produced by reverse-transcribed gene transfer in oocytes.
A critical requirement for integration of retroviruses, other than HIV and possibly related lentiviruses, is the breakdown of the nuclear envelope during mitosis. Nuclear envelope breakdown occurs during mitotic M-phase, the envelope reforming immediately after cell division, thereby permitting the translocation of the retroviral preintegration complex into the nucleus and enabling integration to proceed. In the oocyte, during metaphase II (MII) of the second meiosis, the nuclear envelope is also absent and the oocyte remains in MII arrest for a much longer period of time compared with M-phase in a somatic cell. Pseudotyped replication-defective retroviral vector was injected into the perivitelline space of bovine oocytes during MII. We show that reverse-transcribed gene transfer can take place in an oocyte in MII arrest of meiosis, leading to production of offspring, the majority of which are transgenic. We discuss the implications of this mechanism both as a means of production of transgenic livestock and as a model for naturally occurring recursive transgenesis.
Chan
A W
AW
Endocrinology-Reproductive Physiology Program, University of Wisconsin, 1675 Observatory Drive, Madison, WI 53706, USA.
Homan
E J
EJ
Ballou
L U
LU
Burns
J C
JC
Bremel
R D
RD
D000818:Animals; D030801:Animals, Genetically Modified; D001358:Avian Sarcoma Viruses; D002417:Cattle; D004624:Embryo Transfer; D005260:Female; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006514:Hepatitis B Surface Antigens / Q000235:genetics*; D019868:Kanamycin Kinase / Q000235:genetics*; D008540:Meiosis; D008677:Metaphase; D008979:Moloney murine leukemia virus; D009865:Oocytes / Q000502:physiology*; D016133:Polymerase Chain Reaction / Q000379:methods; D011247:Pregnancy; D012091:Repetitive Sequences, Nucleic Acid; D014162:Transfection / Q000379:methods; D014721:Vesicular stomatitis Indiana virus; D015053:Zygote / Q000502:physiology
D006514:Hepatitis B Surface Antigens; D019868:Kanamycin Kinase