Page 2 Transmission of genetic information between tivo E. coli bacteria occurs during a process known as conjugation. Dr. Lederberg discovered this process in 1946, proving that a form of sexual reproduction occurs in these asexual microorganisms. In the micrograph below, two bacteria make cell-to-cell contact through the formation of a connecting bridge. The bacterium acting as a male donor contributes DNA to the bacterium acting as a female recipient. The recipient incorporates the new Henetic information into its own chromosome by recombination and passes the recombined set on to its progeny by replication. eee Pee ‘68: 1 to a main chromosome, bacteria contain plasmids— tar molecules of double-stranded DNA which ttonomously. Scientists are able to insert foreign plasmids, which then multiply and produce cells genetically identical material, or clones. duce a human gene (1n this case, the one for insulin) nid, scientists take the plasmid out of an E. coli break the plasmid open at a specific site by means of 1 enzyme, and splice in insulin-making human resulting hybrid plasmid can be inserted into coli bacterium, where it replicates together with the making it capable of producing large quantities of Pancreas OS ye ay Human cell gyi (yr Thay, (Dp n from human intestine v E. coli chromosome ot Strand of DNA from Human DNA cut ee oe — human cell into pieces | . Plasmid cut open by by restriction enzyme restriction Te at a specific site > Le Human insulin gene & a “OS TDOCTORAL POSITION Human PT Oe Recombinant DNA insuti MOLECULAR GENETICS (hybrid plasmid) insu gene TRANSCRIPTION AND MUTAGENESIS Hybrid plasmid j Position open for a PhD, in biochemistry or molecular biology inserted into E. coli cell Experience is sought in molcculgr basis of gene expression, especially DNA foolprinting Hinethodology. This will be a collaboratfon to study the interactions of gene expression and lamutagenesis in &. cali, Apply with C.V., onc letter of reference from your Ph.D. sponsor and names of 3 referees to: Bacteria with hybrid plasmid replicate, creating clones capable of producirig insulin Professor Joshua Lederberg