Abstract: Disclosed is a method for the recombinant production of biofilaments, such as spider silk or insect fibroins, using transgenic animals which secrete the biofilaments in their milk and/or urine, and transgenic cells which secrete the biofilaments into culture media. Such a method is useful for producing large quantities of biofilament material. Also disclosed is a nucleic acid molecule for generating such transgenic animals.

Abstract: The invention features methods and apparatuses for spinning silk protein fibers (biofilaments) from recombinant biofilament proteins. The methods are particularly useful for spinning fibers of spider silk or silkworm silk proteins from recombinant mammalian cells and may be used to spin such fibers for use in the manufacture of industrial and commercial products.

Abstract: The present invention provides methods for the large-scale production of recombinant butyrylcholinesterase in cell culture, and in the milk and/or urine of transgenic mammals. The recombinant butyrylcholinesterases of this invention can be used to treat and/or prevent organophosphate pesticide poisoning, nerve gas poisoning, cocaine intoxication, and succinylcholine-induced apnea.

Abstract: The invention features a method which includes the following steps: (a) introducing a transgene into a zygote of a dwarf goat, (b) transplanting the zygote into a pseudopregnant non-dwarf goat, and (c) allowing the zygote to develop to term. In another aspect the invention features a method which includes the following steps: (a) introducing a transgene into an embryo of a dwarf goat, (b) transplanting the embryo into a pseudopregnant non-dwarf goat, and (c) allowing the embryo to develop to term.

Abstract: Disclosed are a cloned cDNA and a cloned genomic DNA, both encoding a .beta.-galactosidase polypeptide from Aspergillus niger. Also disclosed are .beta.-galactosidase expression vectors, transformed host cells that overexpress recombinant A. niger .beta.-galactosidase, and A. niger host cell strains with disrupted endogenous .beta.-galactosidase genes. Also disclosed are transgenic non-human mammals that express A. niger .beta.-galactosidase.

Abstract: Disclosed is a method for expressing a heterologous gene in the mammary gland of a ruminant mammal. The invention is useful for producing a heterologous protein(s) in the milk of the mammal, for producing a heterologous enzyme(s) which is tethered to the mammary epithelial cell membrane and which can act on a component of the milk of the mammal, and for providing an antisense oligonucleotide(s) or ribozyme(s) which inhibits expression of a gene to a mammary epithelial cell. The method involves infusing a liquid complex including a genetic construct into a ductal tree of the mammal. The liquid complex can be infused before the mammal reaches sexual maturity and after the mammal develops a functional streak canal. Alternatively, a liquid complex that is free of live retroviruses can be infused. If desired, the infused genetic construct can be treated with a polycationic compound and/or a lipid to improve the efficiency with which it is taken up by an epithelial cell of the mammary gland.