Attenuated spread of X-inactivation in an X;autosome translocation.
X inactivation in female mammals involves transcriptional silencing of an entire chromosome in response to a cis-acting noncoding RNA, the X inactive-specific transcript (Xist). Xist can also inactivate autosomal sequences, for example, in X;autosome translocations; but here, silencing appears to be relatively inefficient. This variation has been attributed to either attenuated spreading of Xist RNA at the onset of X inactivation or inefficient maintenance of autosomal silencing. Evidence to date has favored the latter. Here, we demonstrate attenuated spreading of Xist RNA at the onset of X inactivation in the T(X;4)37H X;autosome translocation. Our findings provide direct evidence that underlying chromosome/chromatin features can disrupt spreading of the primary inactivating signal.
Popova
Bilyana C
BC
Developmental Epigenetics, Medical Research Council Clinical Sciences Center, Imperial College Faculty of Medicine, Hammersmith Hospital, DuCane Road, London W12 ONN, United Kingdom.
Tada
Takashi
T
Takagi
Nobuo
N
Brockdorff
Neil
N
Nesterova
Tatyana B
TB