In conclusion, the most striking result of our study is the production of pure donor-derived progeny (up to 13.3%) in the span of months when donor germ cells were transplanted into the testes of sexually competent male recipients.
It was easy to distinguish the donor small micromere progeny from the large micromere progeny when the large micromeres fused with non-fluorescent host mesoderm cells to form the skeletal syncytium thereby greatly diluting their fluorescence.
Brueggemann and colleagues carried out partial DNA sequencing at the capsule locus and demonstrated that recombination points likely lay distal to pbp1a and pbp2x based on sequence divergence between putative donor, recipient, and progeny strains [ 12].
It's as if the Kids in the Hall had all become sperm donors and their progeny were sprouting up everywhere.
Donors were F1 progeny of parents collected in Stockholm.
At late time points up to 70% of GFP+ myeloid cells expressed Ki67 and/or cleaved-caspase 3 (C3) (Supplementary Material, Fig. S2), suggesting that a balance between cell proliferation and apoptosis was maintaining homeostasis of donor-derived myeloid progeny in LT engrafted mice.
The transplanted cells successfully developed into functional sperm and were used in artificial fertilization with eggs of the donor species, generating viable progeny of donor origin.
Another caveat was that the progeny of donor GFP+ cells in the peripheral blood were GFP− after 12 weeks, which was anticipated as GFP expression should be lost when the GFP+ cells divide.
In each DAZL-deficient recipient, spermatogenesis was regenerated from the spermatogonial lines that had proliferated in culture (>2 million-fold expansion in cell number) for 5 7 months, yielding 100% germline transmission of the donor haplotype to F1 progeny by natural mating (Fig. 3A C; Table 1).
The transplanted spermatogonial stem cells effectively developed into functional spermatozoa, which due to the absence of sperm competition, transmitted the donor cell haplotype to progeny >7-fold more efficiently from DAZL-deficient recipients than from wildtype litter mates (Fig. 3A C; Table 1).
This resulted from a localized contribution of high IBS from donor Hor211 to 24 progeny; excluding this donor, the highest degree of IBS on 4H also overlapped with the high FST region for most donor lines.
