Four genes encoding eye lens-specific proteins, potential candidate genes for congenital cataract (CC) mutations, were mapped in the mouse genome using a panel of somatic cell hybrids and DNAs from the EU-CIB (European Collaborative Interspecific Backcross). Two of them are lens fiber cell structural proteins: the Cryba1 locus encoding crystallin beta A3/A1 maps to chromosome 11, 2.5 +/- 2.5 cM distal to D11Mit31, and the Crybb2 locus encoding crystallin beta B2 maps to chromosome 5, 9.1 +/- 4.3 cM distal to D5Mit88. The other two genes encode lens-specific gap junction and integral membrane proteins, respectively: The Gja8 locus encoding gap junction membrane channel protein alpha 8, also called connexin50 or MP70, maps to chromosome 3, 11.9 +/- 5.0 cM. distal to D3Mit22, and the Lim2 locus encoding lens intrinsic membrane protein 2, also called MP19, maps to chromosome 7, 2.5 +/- 2.5 cM proximal to Ngfg. All four map positions, when compared with the corresponding positions in human, lie within known regions of conserved synteny between mouse and human chromosomes. (C) 1995 Academic Press, Inc.