The genetics of blind--a lethal factor in mice.

The linkage relationships of the lethal gene blind (Bld) in the mouse were investigated. The gene is located on chromosome 15, between uw and bt. The distance uw--Bld is 28.2 +/- 5.1 cM: Bld--bt is 14.9 +/- 2.7 cM: and Bld--Ca is 24.6 +/- 2.6 cM. Incomplete penetrance and/or reduced viability of Bld/+ animals was found when blind animals were crossed to several strains, but the cross female DBA/2J X male blind yielded complete penetrance and specificity. Evidence is presented for the presence of X-linked modifiers affecting the penetrance and possible increased viability of Bld in strain DBA.