Inherent promoter bidirectionality facilitates maintenance of sequence integrity and transcription of parasitic DNA in mammalian genomes

Table 2 Survey of mouse domesticated genes^a

Repeat family	Repeat type	Number	Chimeric	Bidirectional	Bidirectinal with CpG island
DNA transposons	Tigger	8	2	2	2
	PiggyBac	2	1	0	0
	THAP (P-element)	7	2	1	1
	Others	6	2	3	3
Retrotransposons	Paraneoplastic antigens	7	0	1	1
	Ty3/gypsy	8	0	2	2
	Others	3	0	1	1
Endogenous retroviruses	Syncytin	2	0	0	0
	Others	2	0	2	2
Total		45	7 (15.6%)	12 (26.7%)	12

^a For a more detailed survey of domesticated TEs in the mouse genome see Additional file 2

ISSN: 1471-2164