Abstract: A method of reconstituting an animal embryo involves transferring a diploid nucleus into an oocyte which is arrested in the metaphase of the second meiotic division. The oocyte is not activated at the time of transfer, so that the donor nucleus is kept exposed to the recipient cytoplasm for a period of time. The diploid nucleus can be donated by a cell in either the G0 or G1 phase of the cell cycle at the time of transfer. Subsequently, the reconstituted embryo is activated. Correct ploidy is maintained during activation, for example, by incubating the reconstituted embryo in the presence of a microtubule inhibitor such as nocodazole. The reconstituted embryo may then give rise to one or more live animal births. The invention is useful in the production of transgenic animals as well as non-transgenics of high genetic merit.

Abstract: A method of reconstituting an animal embryo involves transferring a diploid nucleus into an oocyte which is arrested in the metaphase of the second meiotic division. The oocyte is not activated at the time of transfer, so that the donor nucleus is kept exposed to the recipient cytoplasm for a period of time. The diploid nucleus can be donated by a cell in either the G0 or G1 phase of the cell cycle at the time of transfer. Subsequently, the reconstituted embryo is activated. Correct ploidy is maintained during activation, for example, by incubating the reconstituted embryo in the presence of a microtubule inhibitor such as nocodazole. The reconstituted embryo may then give rise to one or more live animal births. The invention is useful in the production of transgenic animals as well as non-transgenics of high genetic merit.

Abstract: A method of reconstituting a mammalian embryo involves transferring the nucleus from a quiescent donor cell into a suitable recipient cell. The donor cell is quiescent, in that it is caused to exit from the growth and division cycle at G1 and to arrest in the G0 state. Nuclear transfer may take place by cell fusion. The reconstituted embryo may then give rise to one or more mammals. The invention is useful in the production of transgenic mammals as well as non-transgenics of high genetic merit.

Abstract: An organism which does not express its natural nisA gene product, but is capable of expressing genes for nisin modification, immunity and translocation out of the cell. The organism may be transformed with a coding sequence for a variant prenisin and appropriate regulatory sequences for expression thereof such that the organism is capable of secreting the corresponding variant nisin. A process for exclusively producing a variant nisin comprises fermenting this organism and obtaining the nisin so produced.

Abstract: Antigenic molecules cause antibodies to be raised against at least some of the 91 to 102 region of a natural growth hormone when parenterally administered in vivo. The molecules can include portions of the 91 to 102 region, particularly the 94 to 98 region. The antibodies are believed to bind to growth hormone on administration and enhance its effect.

Abstract: The nucleic acid coding for an .alpha.-acetolactate synthase from Lactococcus is provided, as well as vectors containing this nucleic acid and the use of these vectors for transforming microorganisms in which the production of .alpha.-acetolactate will be promoted, The nucleic acid comprises one or the other or both of a first segment corresponding to the ilvB gene (which encodes one subunit of .alpha.-acetolactate synthase of Lactococcus lactis subsp. lactis) and a second segment corresponding to the ilvN gene (which encodes a second subunit of .alpha.-acetolactate synthase of Lactococcus lactis subsp. lactis).