Question
92 Dermal fibroblasts are harvested from the skin biopsy specimen of an adult man. These fibroblasts are transduced with genes encoding for transcription factors including Sox2 and c-myc. Under appropriate culture conditions these cells are then able to generate endodermal, mesodermal, and ectodermal cells. Into which of the following kinds of stem cell have these fibroblasts been transformed?
| A. |
Embryonic
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| B. |
Lineage-committed
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| C. |
Mesenchymal
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| D. |
Pluripotent
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Show Answer
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Correct Answer � D
Explanation
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Answer: D Pluripotent
These transformed cells are designated iPS cells because they have been induced to become pluripotent.
This transformation process gets around the problem of using embryonic stem cells derived from manipulation of human embryos, which has ethical and religious concerns.
Embryonic stem cells are totipotent, but they become pluripotent cells
that can further divide into many different cell lines, yet maintain themselves in a replicating pool.
Thus, pluripotent cells are the next best thing compared to embryonic cells for deriving human cells that could replace damaged or diseased tissues.
Further differentiation of pluripotent cells gives rise to cells with more restricted developmental capacity, such as mesenchymal stem cells that can give rise to tissues such as muscle and cartilage but not endodermal or ectodermal cells.
