Table 1.

Examples of exon shuffling and their potential mechanisms

Organism	Involved gene	Mechanism	Microhomology at breakpoint	Reference
Mouse	aA-crystallin	Illegitimate recombination*	CCCAT	(123)
	Gnb5, Myo5a	Nonhomologous recombination*	GG	(124)
Human	LDL receptor, EGF precursor	NA	NA	(125, 126)
	Multiple genes	L1 retrotransposition	NA	(127)
	Kua, UEV	Gene fusion	NA	(128)
	PMCHL1, MCH	Retrotransposition	NA	(129)
	ATM	Retrotransposition	NA	(130)
	TRE-2 (USP6)	Gene fusion	NA	(99)
	PIPSL, PIP5K1A, PSMD4	L1 retrotransposition	NA	(131)

NA, not available.

*Microhomology was shown at the breakpoint, which can be alternatively interpreted to be caused by the FoSTeS/MMBIR mechanism.