Transcript versus transcription?
Numerous sense-antisense gene pairs have been discovered in various organisms. Antisense genes play important roles in establishing parentally imprinted gene expression patterns in mammals. Typically, protein-coding sense genes are reciprocally regulated by their non-coding antisense partners. One example for antisense regulation is the Xist (X-inactive specific transcript) and Tsix gene pair, which is pivotal in X-inactivation. Xist works as a functional RNA molecule that recruits repressive chromatin factors towards one of the female Xs for inactivation. Antisense Tsix transcription negatively regulates Xist and protects one X-chromosome in cis from inactivation by Xist. Albeit, the precise molecular mechanism is still obscure it has been shown that Tsix transcription regulates the chromatin structure by altering histone tail modifications and DNA methylation at the Xist promoter. In addition, Xist and Tsix RNA form an RNA duplexes in vivo and are processed to small RNAs, which have a potential regulatory function. Here we review the latest findings and based on ample experimental data consider models for antisense-mediated gene regulation in X-inactivation.
Shibata
Shinwa
S
Frontier Science Organization, Kanazawa University, Institute for Experimental Animals, Kanazawa University Advanced Science Research Center, Kanazawa, Ishikawa, Japan.
Wutz
Anton
A
D000818:Animals; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D016372:RNA, Antisense / Q000378:metabolism*; D062085:RNA, Long Noncoding; D012333:RNA, Messenger / Q000235:genetics*; D022661:RNA, Untranslated / Q000378:metabolism*; D014158:Transcription, Genetic; D049951:X Chromosome Inactivation
D016372:RNA, Antisense; D062085:RNA, Long Noncoding; D012333:RNA, Messenger; D022661:RNA, Untranslated; C465658:Tsix transcript, mouse