SPERM-MEDIATED GENE-TRANSFER IN THE SILKWORM BOMBYX-MORI

Plasmid DNA containing the CAT reporter gene was injected into the tes tis of V instar silkworm larvae. The persistence, expression, and tran smission of the injected DNA were monitored in the injected individual s till eclosion as well as in the progeny. The DNA injected into the t estis persisted extrachromosomally during the entire period of metamor phosis and was also transferred into the egg via sperm during fertiliz ation. Injected plasmids were rescued from the moths that emerged from the injected larvae and also from the eggs laid by the moths that cop ulated with injected males. Positive signals for CAT assay in the expe rimental samples suggested that the injected DNA was internalized in t he testicular cells and sperm. The persistence, expression, and transm ission of the DNA injected into the testes indicate that sperm-mediate d gene transfer is possible in the silkworm, Bombyx mori. (C) 1998 Wil ey-Liss, Inc.