Artificial insemination and oviposition using cryopreserved sperm in several strains of the silkworm, Bombyx mori

摘要

In our previous experiment, we have found that virgin females of the silkworm inseminated artificially with cryopreserved sperm could oviposit without loss of the fertility, using mainly hybrid strains as material. In the present experiment, the sperm specimens collected from both preserved and original strains were used for artificial insemination after freezing (-196 deg C) and thawing. The sperm was activated by adding trypsin as described previously. In general, the inseminated moths more or less deposited fertilized eggs in every strain used. However, the eggs deposited by inseminated moths was smaller in number and lower in fertility than those deposited by normally mated moths.The number and fertility of eggs were largely different from strain to strain. Although further technical improvement will be necessary for stable cryopreservation of sperm, the present method using artificial insemination with cryopreserved sperm will be very useful for both preservation and maintenance of the genetic resources of Bombyx mori.