Selection against BALB/c strain cells in mouse chimaeras

Abstract

It has been shown previously that BALB/c strain embryos tend to contribute poorly to mouse aggregation chimaeras. In the present study we showed that BALB/c cells were not preferentially allocated to any extraembryonic lineages of mouse aggregation chimaeras, but their contribution decreased during the early postimplantation period and they were significantly depleted by E8.5. The development of BALB/c strain preimplantation embryos lagged behind embryos from some other strains and the contribution that BALB/c and other embryos made to chimaeras correlated with their developmental stage at E2.5. This relationship suggests that the poor contribution of BALB/c embryos to aggregation chimaeras is at least partly a consequence of generalised selection related to slow or delayed preimplantation development. The suitability of BALB/c embryos for maximising the ES cell contribution to mouse ES cell chimaeras is also discussed.

Re-evaluation of the causes of variation among mouse aggregation chimaeras

“…Data from eight series of E12.5 aggregation chimaeras (XM, XN, XP, XR, PCT-V, PCT-VI, GMA and GMB) from four published studies (West and Flockhart, 1994; West et al, 1995b; Tang and West, 2001; MacKay et al, 2005) were analysed in the present study. The strain combinations are shown in ; other details are given in the original papers and are also summarised in Tang et al (2018). The chimaeras were produced by aggregating one Gpi1 a/a and one Gpi1 b/b embryo and the aggregates were transferred to Gpi1 c/c recipient females.…”