Nongenic, bidirectional transcription precedes and may promote developmental DNA deletion in Tetrahymena thermophila

Nongenic, bidirectional transcription has been found to precede developmental DNA deletion in Tetrahymena thermophila, one of the ciliated protozoa, and it may promote it as well. It has been shown that many of the noncoding DNAs are transcribed during nuclear development. Germline-limited sequences excised from the somatic nucleus in the development of the organism have been studied. Transcription seems to target the germline-limited sequences for elimination by altering chromatin to ensure accessibility to excision machinery.