X active specific transcript (XACT)

X active specific transcript (XACT) is a human, primate-specific long non-coding RNA (lncRNA) that is expressed from and coats the active X chromosome in pluripotent human embryonic stem cells[1][2][3][4][5]. Unlike most lncRNAs involved in X-chromosome silencing, such as XIST, XACT is not conserved in mice and appears unique to primate development[2][3]. XACT's expression is limited to pluripotent and early developmental states and decreases upon differentiation[2][3]. It is hypothesized to play a regulatory role in X-chromosome dosage compensation and possibly to modulate or antagonize the gene-silencing activity of XIST, preventing premature X-chromosome inactivation prior to implantation. It does not directly encode a protein or act as a therapeutic target (such as a receptor, enzyme, or transporter)[1][2][3][4][5][6].

Other names

X active coating transcriptX-active coating transcriptXACT RNA