Aggregation of pre‐implantation embryos improves establishment of parthenogenetic stem cells and expression of imprinted genes

Abstract

Parthenogenetic embryonic stem cells (PgES) might advance cell replacement therapies and provide a valuable in vitro model system to study the genomic imprinting. However, the differential potential of PgES cells was limited. It could result from relative low heterology of PgES cells compared with ES cells from fertilization (fES), which produce different expression of most imprinted genes. Here, we described the establishment of PgES cells by aggregating parthenogenetic embryos at the 8-cell stage (aPgES cells), which may increase heterozygy. We found that derivation of aPgES cells in association with an increased number of inner cell mass cells by aggregating was more efficient than that of PgES cells from a single parthenogenetic blastocyst. The aPgES cells have normal karyotype, stain positive for alkaline phosphatase, express high levels of ES cell markers and can differentiate into teratomas composed of the three germ layers. Moreover, compared with PgES cells, the more highly upregulated paternally expressed imprinted genes were observed in aPgES cells, the same change was not shown in aPg blastocysts. This suggested that the aggregation induced effect could modify the expression of paternally expressed imprinted genes. Our studies showed that aPgES cells, the expression of imprinted genes in which more closely resemble fES cells than PgES cells, would contribute to all organs and avoiding immuno-rejection, which may provide invaluable material for regeneration medicine.

Blastomeres aggregation as an efficient alternative for trophoblast culture from porcine parthenogenetic embryos

“…; Shan et al . ); however, we found using more embryos with small volume of medium in mircodrops was easier for manipulation and gave satisfactory results. In some trials we found that embryos began to cleave and form blastomeres as soon as culture conditions started (Fig.…”

“…; Brevini & Gandolfi ; Hall ; Shan et al . ). Organisms with a single copy of their genome provide a basis for genetic analyses where any recessive mutation of essential genes will show a clear phenotype due to the absence of a second gene copy (Carette et al .…”

Chromosomal Abnormalities in Embryonic and Somatic Stem Cells

“…Chromosome deletions and translocations have also been reported in the hPES-2 cell line, when cultivated for 120 passages [Mai et al, 2007]. Few cytogenetic data are available on mouse pESC lines, reporting a stable karyotype during culture (up to passage 120), analyzed by standard G-banding [Shao et al, 2007;Ju et al, 2008;Shan et al, 2012].…”

Embryos aggregation improves development and imprinting gene expression in mouse parthenogenesis

“…Our previous study indicated that the maternal expressed imprinting genes downregulated in aPgB (Shan et al . ). So we hypothesized that increasing the number of aggregated embryos might improve the development of parthenogenetic mice.…”

“…Meanwhile, the expression of maternal expressed imprinting genes such as H19, Gtl2, Igf2r decreased in aggregated blastocyst (Shan et al . ).…”