What is the outcome when pluripotency factors stimulate the expression of Tsix in early embryonic development?

• A. Pluripotency factors cause both X chromosomes to be inactivated.
• B. Tsix expression leads to the activation of Y-linked genes.
• C. Xist expression is repressed, preventing X chromosome inactivation.
• D. Xist expression is increased, leading to X chromosome inactivation.

Answer: (C)

Verified step by step guidance

1. Understand the role of pluripotency factors in early embryonic development: these factors maintain the cells in a pluripotent state and regulate gene expression related to X chromosome inactivation.
2. Recognize that Tsix is an antisense transcript of the Xist gene, and its expression negatively regulates Xist expression.
3. Recall that Xist is responsible for initiating X chromosome inactivation by coating the X chromosome and silencing it.
4. Analyze how stimulation of Tsix expression by pluripotency factors leads to repression of Xist, thereby preventing the initiation of X chromosome inactivation.
5. Conclude that when pluripotency factors stimulate Tsix, Xist expression is repressed, which maintains both X chromosomes in an active state during early embryonic development.