Regular ArticleA Novel ES Cell Line, TT2, with High Germline-Differentiating Potency
Abstract
In producing mutant mice by gene-targeting and gene-trapping in embryonic stem (ES) cells, the efficient colonization of the mutant ES cells into germline is still a critical matter. We have established a new line of ES cells, TT2, from an Fl embryo between a C57BL/6 female and a CBA male. When the TT2 cells were injected into blastocysts, the colonization into each tissue was very low. However, when injected into eight-cell embryos, the cells segregated inside the blastomeres, localized in an inner cell mass of blastocysts developed 1 day later, and colonized efficiently in each tissue of the pups. The pups were disproportionately male, about half of which were composed of TT2-derived cells primarily; in more than 70% of the males, TT2-derived cells were dominant, accounting for over half of the total cells. When these males were mated, they exclusively yielded TT2-derived offspring. The germline-differentiating potency was stable during 3 weeks of culture. Twenty-one of 24 mutant clones independently isolated yielded germline chimeras, and 19 clones yielded them in a rate comparable to that of the parent cells. Thus, TT2 cells can serve as a valuable vehicle for the production of mutant mice.
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Di-n-butyl phthalate promotes the neural differentiation of mouse embryonic stem cells through neurogenic differentiation 1
2024, Environmental PollutionAn understanding of the risk of gene deletion and mutation posed by endocrine-disrupting chemicals (EDCs) is necessary for the identification of etiological reagents for many human diseases. Therefore, the characterization of the genetic traits caused by developmental exposure to EDCs is an important research subject. A new regenerative approach using embryonic stem cells (ESCs) holds promise for the development of stem-cell-based therapies and the identification of novel therapeutic agents against human diseases. Here, we focused on the characterization of the genetic traits and alterations in pluripotency/stemness triggered by phthalate ester derivatives. Regarding their in vitro effects, we reported the abilities of ESCs regarding proliferation, cell-cycle control, and neural ectoderm differentiation. The expression of their stemness-related genes and their genetic changes toward neural differentiation were examined, which led to the observation that the tumor suppressor gene product p53/retinoblastoma protein 1 and its related cascades play critical functions in cell-cycle progression, cell death, and neural differentiation. In addition, the expression of neurogenic differentiation 1 was affected by exposure to di-n-butyl phthalate in the context of cell differentiation into neural lineages. The nervous system is one of the most sensitive tissues to exposure to phthalate ester derivatives. The present screening system provides a good tool for studying the mechanisms underlying the effects of EDCs on the developmental regulation of humans and rodents, especially on the neuronal development of ESCs.
Hepatic phosphatidylcholine catabolism driven by PNPLA7 and PNPLA8 supplies endogenous choline to replenish the methionine cycle with methyl groups
2023, Cell ReportsCholine supplies methyl groups for regeneration of methionine and the methyl donor S-adenosylmethionine in the liver. Here, we report that the catabolism of membrane phosphatidylcholine (PC) into water-soluble glycerophosphocholine (GPC) by the phospholipase/lysophospholipase PNPLA8-PNPLA7 axis enables endogenous choline stored in hepatic PC to be utilized in methyl metabolism. PNPLA7-deficient mice show marked decreases in hepatic GPC, choline, and several metabolites related to the methionine cycle, accompanied by various signs of methionine insufficiency, including growth retardation, hypoglycemia, hypolipidemia, increased energy consumption, reduced adiposity, increased fibroblast growth factor 21 (FGF21), and an altered histone/DNA methylation landscape. Moreover, PNPLA8-deficient mice recapitulate most of these phenotypes. In contrast to wild-type mice fed a methionine/choline-deficient diet, both knockout strains display decreased hepatic triglyceride, likely via reductions of lipogenesis and GPC-derived glycerol flux. Collectively, our findings highlight the biological importance of phospholipid catabolism driven by PNPLA8/PNPLA7 in methyl group flux and triglyceride synthesis in the liver.
GAREM1 is involved in controlling body mass in mice and humans
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Lineage tracing analysis defines erythropoietin-producing cells as a distinct subpopulation of resident fibroblasts with unique behaviors
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USP40 deubiquitinates HINT1 and stabilizes p53 in podocyte damage
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