Four subfamilies of the SLC39 family are named by Taylor and Nicholson [23]. DrZIP1 and FrZIP1 are members of the ZIP subfamily II. At, Arabidopsis thaliana (thale cress); Ce, the nematode worm Caenorhabditis elegans; Dm, Drosophila melanogaster (fruitfly); Dr, Danio rerio (zebrafish); Gg, Gallus gallus (chicken); Gm, Glycine max (soybean); Hs, Homo sapiens (human); Mt, Medicago truncatula (barrel medic); Mx, the Gram-negative bacterium M. xanthus; Om, Oncorhynchus mykiss (rainbow trout); Sc, S. cerevisiae (baker's yeast); Tc, Thlaspi caerulescens (stone cress); and Tr, Ta. rubripes (seawater pufferfish).