Fig. 4
From: Hagfish genome reveals parallel evolution of 7SL RNA-derived SINEs
A model of the birth of SINE1-1_EBu. Internal deletion of RTE-4_EBu and RTE-2_EBu generated non-autonomous bipartite retrotransposons. A chimeric SINE family, similar to SINE2-10_EBu, was generated from a non-autonomous RTE-4_EBu derivative and a SINE family having tRNA head and UCON3 domain. The 3′ part of this SINE family was replaced by non-autonomous RTE-2_EBu derivative, which may be intact or a part of SINE, generating a SINE family similar to SINE2–1/1B_EBu. Finally, the chimera formation between a 7SL RNA and SINE2–1/1B_EBu-like SINE family generated SINE1–1_EBu. Internal deletion of 7SL RNA occurred either before or after the chimera formation. SINE1–1_EBu is composed by 5 parts: 5′ region of 7SL RNA, 3′ region of 7SL RNA, 5′ region of RTE-4_EBu, 5′ region of RTE-2_EBu, and 3′ region of RTE-2_EBu