Abstract
An efficient method is described for obtaining transformants in Phycomyces by microinjection of plasmid DNA carrying the kanamycin resistance gene from Tn903 into a young sporangium. Approximately 9% of the colonies, germinated from the spores which were developed in the sporangium, were resistant to G418 when a 36 ng sample of the transforming plasmid DNA was injected into a sporangium. The transformation efficiency (transfomants/total colonies) was about 350 times higher than that (transfomants/total protoplasts) obtained with the ordinary protoplast method.