Inhibition of Apoptosis Reduces Diploidization of Haploid Mouse Embryonic Stem Cells during Differentiation

Abstract

Summary Phenotypes of haploid embryonic stem cells (haESCs) are dominant for recessive traits in mice. However, one major obstacle to their use is self-diploidization in daily culture. Although haESCs maintain haploidy well by deleting p53 , whether they can sustain haploidy in differentiated status and the mechanism behind it remain unknown. To address this, we induced p53 -deficient haESCs into multiple differentiated lineages maintain haploid status in vitro . Haploid cells also remained in chimeric embryos and teratomas arising from p53 -null haESCs. Transcriptome analysis revealed that apoptosis genes were downregulated in p53 -null haESCs compared with that in wild-type haESCs. Finally, we knocked out p73 , another apoptosis-related gene, and observed stabilization of haploidy in haESCs. These results indicated that the main mechanism of diploidization was apoptosis-related gene-triggered cell death in haploid cell cultures. Thus, we can derive haploid somatic cells by manipulating the apoptosis gene, facilitating genetic screens of lineage-specific development.

The milestone of genetic screening: Mammalian haploid cells

“…2 B) in HAP1 cell lines and mouse haESCs could stabilize haploidy genomes significantly [41] . Similar evidence proved that deletion of p53 also facilitated derivation of mouse haiTSCs by stabilizing haploidy during conversion [34] A recent study showed that knockout of p53 can significantly down regulate the expression of apoptosis related genes in haESCs, thus maintaining the stability of haploids [42] . If the apoptosis related gene p73 was knocked out, haESCs could also maintain haploidy steadily, which suggested that apoptosis is another potential cause of diploidization in haploid cell cultures [42] .…”

Recombinant human erythropoietin attenuates hepatic dysfunction by suppressing hepatocellular apoptosis in lipopolysaccharide‑induced disseminated intravascular coagulation in rats

“…This issue thus needs to be clarified in future studies. Similarly, apoptosis requires multidimensional evaluations (32,33), and evaluations using cell viability, DRAQ7 or caspase expression should be performed in the future. Finally, creatinine and GFD were used as markers of renal function in the present study, but measurement of urinary protein and pathological examinations may also be warranted to evaluate renal function more accurately.…”

A Genetic Screen Identifies Etl4-Deficiency Capable of Stabilizing the Haploidy in Embryonic Stem Cells

“…Recent studies have demonstrated that the mitotic process in haploid cells is different from that in diploid cells, the main differences laying in prolonged G2/M phase ( Li et al., 2017 ) and metaphase ( Guo et al., 2017 ), mitotic slippage ( He et al., 2017 ), or failed cytokinesis ( Leng et al., 2017 ). It was also reported that overexpression of Dnmt3b ( He et al., 2018 ), or deletion of P53 ( Olbrich et al., 2017 ) or P73 ( Zhang et al., 2020 ) in mouse haESCs could decrease self-diploidization. Another study showed that 10-Deacetyl-baccatin-III (DAB), a precursor of Taxol, selectively favors haploidy in mammalian cells ( Olbrich et al., 2019 ).…”