Table 1.

Non-replicative DNA polymerases/transferases: impact of their inactivation on Ig gene hypermutation in the mouse.

polymerase family	polymerase name	role in hypermutation	specific comments
A	Pol theta (θ)	no	conflicting data
	Pol nu (ν)	not tested
B	Pol zeta (ζ)	not settled	embryonic lethal phenotype
X	Pol beta (β)	no
	Pol lambda (λ)	no
	Pol mu (μ)	no
	Tdt	no
Y	Pol eta (η)	yes
	Pol iota (ι)	no
	Pol kappa (κ)	no	back-up of Pol eta in Pol eta-deficient animals
	Rev1	yes	strand-biased contribution