Induced Pluripotent Stem Cells Concepts

1. What was the primary goal of the Yamanaka (2006) study?

• To differentiate embryonic stem cells into fibroblasts

• To discover a method for cloning adult mice

• To induce pluripotency in somatic cells using defined factors

• To identify naturally occurring stem cells in adult tissues

Which cell type did Yamanaka and colleagues reprogram into induced pluripotent stem cells (iPSCs) in the 2006 paper?

• Neural stem cells

• Mouse embryonic fibroblasts (MEFs)

• Human fibroblasts

• Bone marrow cells

Which four transcription factors were found to be sufficient for reprogramming somatic cells to iPSCs?

• Sox2, Klf4, c-Myc, Oct4

• Nanog, Oct4, Lin28, Sox2

• Oct4, Sox2, c-Myc, Lin28

• c-Myc, Klf4, Nanog, Oct4

How did Yamanaka screen for successful reprogramming in the initial experiments?

• By checking for spontaneous differentiation

• By selecting for antibiotic resistance under a pluripotency gene promoter

• By measuring cell size and morphology

• By labeling cells with fluorescent proteins

What is one limitation of the iPSCs generated in the 2006 study?

• They could not form embryoid bodies

• They failed to express any pluripotency markers

• They were not able to contribute to germline transmission

• They required feeder cells for survival

What method did Yamanaka use to deliver the four reprogramming factors into cells?

• CRISPR-Cas9

• Lentiviral transduction

• Electroporation

• Retroviral vectors

What was a key conclusion of the study?

• Pluripotency is fixed and cannot be induced

• Somatic cells can be reprogrammed into a pluripotent state using defined factors

• Adult stem cells are more potent than embryonic stem cells

• Only embryonic cells can express Oct4