Distribution of metallicity gradients as a function of distance from the nearest large LG spiral. Top: satellites of the Milky Way, M31, and the isolated systems are marked as blue circles, orange squares, and red triangles, respectively. Dwarf galaxies that might have experienced a past merger event are marked with an open circle. Bottom: same as above, but with data colour-coded according to their HI content; circles mark a full detection, and squares mark the 5-σ upper limit (data from Putman et al. 2021, and references therein). On the y-axes, the left panels show the metallicity gradients in units of the 2D SMA half-light radius, and in the right panels, they are in units of the physical radius.