Fig. 1: A cataract suppressor is mapped to a chromosome 7 interval where the periaxin gene is located.
From: Periaxin gene variants are linked to age-related cataracts in Cx46 deficient lenses
a Lens images of Cx46KO mice reveal a severe nuclear cataract in the 129-strain genetic background (129/129), a very mild cataract in the B6-strain genetic background (B6/B6), and a mild cataract in the first-generation mixed genetic background of 129 and B6 (N1 129/B6) at 4 weeks of age. Scale bar, 1 mm. b Cx46KO lens images from second-generation littermates with mixed genetic backgrounds (N2 129/B6) at 4 weeks old, generated by intercrossing the N1 129/B6 Cx46KO mice, show variable nuclear cataracts ranging from mild to intermediate to severe opacities. Scale bar, 1 mm. c Lens images of 6-week-old N14 littermates show a severe nuclear cataract in a 129 genetic background mouse (129/129), an intermediate cataract in a heterozygous 129/B6L mouse (one Chr7-129 allele and one Chr7-B6L allele), and a mild cataract in a homozygous B6L/B6L mouse. These littermates were generated by intercrossing N13 heterozygous Chr7(129/B6L) Cx46KO male and female mice. A bar graph compares the light scattering intensity of 6-week-old Cx46KO lenses across the 129/129, 129/B6L, and B6L/B6L backgrounds (*P < 0.05, ***P < 0.001; n = 6 lenses per genotype). Scale bar, 1 mm. d Representative lens images of 6-week-old Cx46KO mice from two different Chr7 crossover lines: B6S/B6S and B6L/B6L. The B6S/B6S mouse displays a severe cataract, while the B6L/B6L mouse exhibits a mild cataract. The lower panel illustrates the Chr7 mapping results for these two crossover lines using the markers D7Mit23, D7Mit294, and D7Mit117. The B6L/B6L-Cx46KO mouse line carries two copies of a long Chr7-B6L fragment (~4.4 Mb of B6 genomic DNA flanked by markers D7Mit23 and D7Mit117, shown in green), while the B6S/B6S-Cx46KO line contains two copies of a short Chr7-B6 fragment (<2 Mb of B6 genomic DNA located between D7Mit23 and D7Mit294, shown in green). The 129 Chr7 genomic DNAs are shown in red. The cataract suppressor is mapped to the 28.07–30.71 Mb interval between the linkage markers D7Mit294 and D7Mit117, where the periaxin gene is located. Scale bar, 1 mm.
