Developmental potential of biopsied mouse blastocysts.

The health of a preimplantation embryo can be diagnosed in one or more cells biopsied from the conceptus. Here, we tried to evaluate the impact of biopsy of some trophectoderm cells from hatching mouse blastocysts on their further in vitro implantation and early egg cylinder formation. Of 374 blastocysts evaluated 112 hours after hCG, 34% initiated hatching with a small number of mural, polar, or intermediate trophectoderm cells. Half of 59 embryos that underwent induction of hatching by zona puncturing herniated some cells through this opening. After removal of cells with a glass microneedle from spontaneously hatching blastocysts, viability assessed by vital FDA staining was impaired, as well as the in vitro zona pellucida shedding and implantation. When polar trophectoderm cells were biopsied, a significantly lower number of embryos reached the egg cylinder stage.