Fig. 3.

—Mechanisms for retrocopy transcription. (A) The retrocopy might acquire regulatory regions from an existing gene after inserting within that gene. (B) Regulatory regions might be carried ouver from the parental gene, if an aberrant/longer transcript of the parental gene is produced. (C) A regulatory region might evolve from a proto-regulatory region or from a region with no regulatory function. (D) A retrocopy might be expressed from a bidirectional regulatory region, if inserted in head-to-head orientation. (E) A retrocopy might express if inserted between a gene and its regulatory region. See text for more details.