The open-eyelid mutation, lidgap-Gates, is an eight-exon deletion in the mouse Map3k1 gene

The BALB/cGa mouse strain and its descendants, now called the SELH/Bc strain, have produced two waves of high frequency of spontaneous heritable mutations. One of these, the recessive lidgap-Gates (1g(Ga)) mutation, causes the same open-eyelids-at-birth phenotype as the gene knockout Mutations of Map3k1 and co-maps to distal Chr 13. The 1gGa mutation is demonstrated to be a 27.5-kb deletion of exons 2-9 in the Map3k1 gene, the first spontaneous mutant allele described at this locus. The 1gGa mutation is consistent with a pattern suggesting that the waves of mutation in BALB/cGa and its descendants tend to be large deletions or ETn insertions, whose elevated rate of Occurrence is due to an unknown mechanism. (C) 2004 Elsevier Inc. All rights reserved.