Abstract
Gene libraries have been constructed from the messenger ribonucleic acid (mRNA) isolated from venom glands of different poisonous animals such as snakes, scorpions, and snails. The gene banks thus created contain recombinant clones harboring DNA sequences encoding toxins with various pharmacological activities, ranging from myonecrosis-inducing to those affecting neuronal transmission. A number of these clones have been isolated and characterized, and gene expression has been attempted with limited success in Escherichia coli, baculovirus, and in two mammalian cell expression systems by using either cDNAs or synthetically-constructed genes.