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Although the yellowtail (Seriola quinqueradiata) is the fish most commonly farmed in Japan, breeding of this species has not yet started. This is primarily due to the lack of sufficiently sophisticated methods for manipulating gametogenesis, which makes it difficult to collect gametes from specific dams and sires. If it were possible to produce large numbers of surrogate fish by transplanting germ cells isolated from donor individuals harboring desirable genetic traits, then the probability of acquiring gametes carrying the donor-derived haplotype would increase, and breeding programs involving this species might increase as a result. As a first step, we established a method for the allogeneic transplantation of yellowtail spermatogonia and the production of donor-derived offspring. Donor cells were collected from immature (10-month-old) yellowtail males with testes containing abundant type A spermatogonia, labeled with PKH26 fluorescent dye, and transferred into the peritoneal cavities of 8-day-old larvae. Fluorescence observation at 28 days post-transplantation revealed that PKH26-labeled cells were incorporated into recipients' gonads. To assess whether donor-derived spermatogonia could differentiate into functional gametes in the allogeneic recipient gonads, gametes collected from nine male and four female adult recipients were fertilized with wild-type eggs and milt. Analysis of microsatellite DNA markers confirmed that some of the first filial (F(1)) offspring were derived from donor fish, with the average contribution of donor-derived F(1) offspring being 66% and the maximum reaching 99%. These findings confirmed that our method was effective for transplanting yellowtail spermatogonia into allogeneic larvae to produce donor-derived offspring.

We demonstrate here the single-atom migration of Tb, Gd, or Ce metal from cage to cage through an intentionally induced atomic path within a carbon nanopeapod. The atomic path is actually an atomic defect (vacancy) induced at the fullerene cage during TEM observation. It is therefore proved that the atomic cage can be punctured by electron irradiation so that the imprisoned metal atoms can break out. The results definitively indicate the possibilities for an alternative method to transfer single atoms without using SPM tips but by using an "atomic carry-bag" such as fullerene.