Generation of developmentally competent oocytes and fertile mice from parthenogenetic embryonic stem cells

Parthenogenetic embryos,created by activation and diploidization of oocytes,arrest at mid-gestation for defective paternal imprints,which impair placental development.Also,viable offspring has not been obtained without genetic manipulation from parthenogenetic embryonic stem cells(pESCs)derived from parthenogenetic embryos,presumably attributable to their aberrant imprinting.We show that an unlimited number of oocytes can be derived from pESCs and produce healthy offspring.Moreover,normal expression of imprinted genes is found in the germ cells and the mice.pESCs exhibited imprinting consistent with exclusively maternal lineage,and higher X-chromosome activation compared to female ESCs derived from the same mouse genetic background.pESCs differentiated into primordial germ cell-like cells(PGCLCs)and formed oocytes following in vivo transplantation into kidney capsule that produced fertile pups and reconstituted ovarian endocrine function.The transcriptome and methylation of imprinted and X-linked genes in pESC-PGCLCs closely resembled those of in vivo produced PGCs,consistent with efficient reprogramming of methylation and genomic imprinting.These results demonstrate that amplification of germ cells through parthenogenesis faithfully maintains maternal imprinting,offering a promising route for deriving functional oocytes and having potential in rebuilding ovarian endocrine function.

Characterization of oogonia stem cells in mice by Fragilis

Dear Editor,Identification of oogonia stem cells would have great potentials in infertility treatment and fertility preservation.Here we tested whether Fragilis/lfitm3 can identify oogonia stem cells in fetal mouse ovaries and their molecular features,if it can,and whether the oogonia stem cells marked by Fragilis can be found in the postnatal ovaries.

Correction to:Characterization of oogonia stem cells in mice by Fragilis

Figure 2.Neo-meiosis and functional test of oocytes developed from Fragilis*cells.(A)Immunofluorescenee of SCP1(red)and SCP3(green,appear as yellowish by merge with SCP1)showing pachytene spread of E12.5 Fragilis*cells obtained from aggregates with fetal E12.5 somatic cells 6 days following transplantation,compared with those of E17.5 ovaries.Right panel,Percentage of synaptonemal complex elements based on count of spread at pachytene(n-22).Scale bar=5 pm.(B)Representative immunofluorescence of MLH1 foci at pachytene stage by co-immunostaining of SCP3(red)and MLH1(green).Right panel,Statistics of MLH1 foci represents 20 spread per each group.

Overexpression of Hdac6 enhances resistance to virus infection in embryonic stem cells and in mice

Dear Editor Histone deacetylase 6 （Hdac6） is a mostly cytoplasmic class II HDAC. Many proteins have been identified as substrates of Hdac6. Among them, the most well characterized sub- strate of Hdac6 is a-tubulin. Through deacetylating acety- lated lysine 40 in a-tubulin, Hdac6 modulates the acetylation of microtubules （Hubbert et al., 2002）.

Telomere elongation in parthenogenetic stem cells

Dear Editor, Parthenogenetic embryonic stem （pES） cells, generated from oocytes by artificial activation without involvement of fertilization, show differentiation and pluripotency as evi- denced by their capacity to generate germline chimeras and all pES pups by tetraploid embryo complementation, indi- cating the ability of pES cells to form all cell types in the body （Chen et al., 2009; Liu et al., 2011）. Indeed, pES cells can repair injured muscle （Koh et al., 2009） and cardiomyocytes with reduced risk of tumorigenesis （Liu et al., 2013）,

Correction to: Characterization of oogonia stem cells in mice by Fragilis

Correction to:Protein Cell 2019,10(11):825831 htps://oi.org/0/.007/13238-019-0106545-0 In the original publiq|htps://doi.Org/10.1007/sI P 1D,Y-axis is incorrectly publisheb.Thooonoot aooninrgorrodld be read as Fragilis+/SSEA1+and the correct Figure 1 is provided in this correction.