Developmental competence of interspecies cloned embryos produced using cells from large Japanese field mice (Apodemus speciosus) and oocytes fromlaboratory mice (Mus musculus domesticus)

摘要

The large Japanese field mouse ( ) is endemic to Japan and may be used as an animal model for studies related to environmental pollution, medicalscience, and basic biology. However, the large Japanese field mouse has low reproductive ability due to the small number of oocytes ovulated per female. To produce experimentalmodels, we investigated the developmental potential of interspecies somatic cell nuclear transfer (iSCNT) embryos produced by fusing tail tip cells fromthe large Japanese field mouse with enucleated oocytes from laboratory mice ( ). Only a small number of iSCNT embryos developed to the 4-cell(0–4%) and blastocysts (0–1%) stages under sequential treatment using trichostatin A (TSA) and vitamin C (VC) supplemented with deionized bovine serum albumin (d-BSA). Thissequential treatment led to the reduction in H3K9 trimethylation and did not affect H3K4 trimethylation in at least the 2-cell stage of the iSCNT embryos. Moreover, iSCNT embryosthat received tail tip cells with exposure treatment to ooplasm from cell fusion to oocyte activation or VC treatment prior to cell fusion did not exhibit significant development improvement compared to that of each control group. This suggests that large Japanese field mice/laboratory mice iSCNT embryos that received sequentialtreatment using TSA and VC with d-BSA may have slightly better developmental potential beyond the 4-cell stage. Our results provide insights into the reprogramming barriersimpeding the wider implementation of iSCNT technology.