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Browsing by Author "Powell, Anne M."

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    Bovine trophectoderm cells induced from bovine fibroblasts with induced pluripotent stem cell reprogramming factors
    Talbot, Neil C.; Sparks, Wendy O.; Phillips, Caitlin E.; Ealy, Alan D.; Powell, Anne M.; Caperna, Thomas J.; Garrett, Wesley M.; Donovan, David M.; Blomberg, Le Ann (2017-06)
    Thirteen independent induced bovine trophectroderm (iBT) cell lines were established by reprogramming bovine fetal liver-derived fibroblasts after viral-vector transduction with either six or eight factors, including POU5F1 (OCT4), KLF4, SOX2, MYC, NANOG, LIN28, SV40 large T antigen, and hTERT. Light-and electron-microscopy analysis showed that the iBT cells had epithelial cell morphology typical of bovine trophectoderm cells. Reverse-transcription-PCR assays indicated that all of the cell lines expressed interferon-tau (IFNT) at passages 1 or 2. At later passages (>= passage 8), however, immunoblot and antiviral activity assays revealed that more than half of the iBT cell lines had stopped expressing IFNT. Messenger RNAs specific to trophectoderm differentiation and function were found in the iBT cell lines, and 2-dimensional gel analysis for cellular proteins showed an expression pattern similar to that of trophectoderm cell lines derived from bovine blastocysts. Integration of some of the human reprogramming factors, including POU5F1, KLF4, SOX2, MYC, NANOG, and LIN28, were detected by PCR, but their transcription was mostly absent in the iBT cell lines. Gene expression assessment of endogenous bovine reprogramming factor orthologs revealed endogenous bLIN28 and bMYC transcripts in all; bSOX2 and bNANOG in none; and bKLF4 and bPOU5F1 in less than half of the iBT cell lines. These results demonstrate that bovine trophectoderm can be induced via reprogramming factor expression from bovine liver-derived fibroblasts, although other fibroblast populations-e.g., derived from fetal thigh tissue-may produce similar results, albeit at lower frequencies.
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    Extraembryonic Endoderm (XEN) Cells Capable of Contributing to Embryonic Chimeras Established from Pig Embryos
    Park, Chi-Hun; Jeoung, Young-Hee; Uh, Kyungjun; Park, Ki-Eun; Bridge, Jessica; Powell, Anne M.; Li, Jie; Pence, Laramie; Zhang, Luhui; Liu, Tianbin; Sun, Hai-Xi; Gu, Ying; Shen, Yue; Wu, Jun; Belmonte, Juan-Carlos Izpisua; Telugu, Bhanu P. (2021-01-12)
    Most of our current knowledge regarding early lineage specification and embryo-derived stem cells comes from studies in rodent models. However, key gaps remain in our understanding of these developmental processes from nonrodent species. Here, we report the detailed characterization of pig extraembryonic endoderm (pXEN) cells, which can be reliably and reproducibly generated from primitive endoderm (PrE) of blastocyst. Highly expandable pXEN cells express canonical PrE markers and transcriptionally resemble rodent XENs. The pXEN cells contribute both to extraembryonic tissues including visceral yolk sac as well as embryonic gut when injected into host blastocysts, and generate live offspring when used as a nuclear donor in somatic cell nuclear transfer (SCNT). The pXEN cell lines provide a novel model for studying lineage segregation, as well as a source for genome editing in livestock.