Abstract: A disappearing ink marking system adaptable to a sole of a user that includes an upper layer, an intermediate layer affixed to the upper layer, a lower layer affixed to the intermediate layer, a reservoir tube passing into the intermediate layer and in fluid communication therewith, disappearing ink, and at least one image block affixed to the lower layer and in fluid communication with the intermediate layer. Disappearing ink flowing through the reservoir tube escapes through the plurality of reservoir tube apertures and enters the intermediate layer and is absorbed therein where upon when pressure is applied to the intermediate layer and the at least one image block the disappearing ink is forced from the intermediate layer through the at least one lower layer aperture and into the at least one image block which in turn causes the at least one image block to disperse the disappearing ink and leave a temporary image.

Abstract: Novel vectors and methods for a single-stranded DNA mediated gene transfer system via transformation, fusion or transduction of Streptomyces, other actinomycetes, and E. coli using a variety of vectors. Phasmid shuttle vectors of the invention are particularly useful as single-stranded vectors that appear to bypass one or more host cell restriction systems, and thus increase the efficiency of gene transfer into highly restrictive host cell systems. New and useful vectors are provided that allow for the cloning of genes both for increasing the yields of known antibiotics and also for producing new antibiotics, antibiotic derivatives, or any other useful gene product, including a variety of mammalian protein products.

Abstract: A novel gene conferring resistance to picromycin in Streptomyces and related organisms was cloned from a genomic library of Streptomyces felleus DNA. The novel picromycin resistance-conferring gene can be isolated on an .about.2.8 kb PvuII fragment by subcloning the restriction fragment from plasmid pOJ321. This PvuII fragment contains all of the information required for the expression of the picromycin resistant phenotype in Streptomyces. Methods for inducing resistance, as well as vectors and transformants containing the novel picromycin resistance gene, are provided.

Abstract: The present invention is a method for isolating antibiotic biosynthetic genes. To practice the method, an antibiotic resistance-conferring DNA segment is labelled and used as a probe to find, via DNA hydridization, homologous DNA in a genetic library which comprises chromosomal and plasmid DNA of an antibiotic-producing organism. Individual vectors of the genetic library which hybridize to the antibiotic resistance-conferring gene, and which comprise .about.1-45 kb of contiguous DNA from the antibiotic-producing organism, which also comprise an antibiotic biosynthetic gene. The present method is exemplified by using the erythromycin resistance-conferring gene of Streptomyces erythreus to clone the erythromycin biosynthetic pathway from the same organism. The erythromycin biosynthetic pathway isolated with the present method synthesizes erythromycin when introduced into S. lividans TK23.

Abstract: Novel recombinant DNA cosmid shuttle vectors and a method of using them in the construction of genomic DNA libraries are described. The vectors demonstrate the incorporation of both the size selection and in vitro packaging mechanisms of lambda into a Streptomyces-E. coli shuttle vector by the incorporation of two or more COS sequences of bacteriophage lambda.

Abstract: A novel method of selecting Streptomyces recombinant DNA-containing host cells and vectors useful in exemplifying the method are described. The vectors confer apramycin resistance to sensitive Streptomyces host cells and thus provide a convenient method of selecting Streptomyces transformants. The apramycin resistance-conferring gene used in the method is an acetyltransferase aac(3)IV gene and can be isolated from E. coli K12 BE1041/pKC309 (NRRL B-15827) on an .about.1.5 kb PstI-EcoRI restriction fragment.