Xenbase Image ID: 144753

Figure 3. A SNP variant within the Fscn2 gene is unique to the DBA/2J strain and changes a highly conserved amino acid. a , Nucleotide variation among 20 inbred mouse strains for the rs26996001 SNP, which is located within exon 1 of the Fscn2 gene. DBA/2J is the only strain examined with an adenine (A) at this position; all other strains have guanine (G). The G to A nucleotide substitution causes an amino acid change from arginine (R) to histidine (H) at position 109 of the mouse FSCN2 protein (NP_766390). b , Evolutionary conservation of the FSCN2 arginine (R) residue that is mutated in DBA/2J mice. This residue (highlighted in blue) is conserved in fascin proteins of all mammalian species examined, as well as fascins of other vertebrate species. c , Genealogy of DBA-related inbred mouse strains and their association with the Fscn2 SNP. All are direct descendants of the original dba strain developed by C. C. Little in 1909. Shown are the approximate dates when these DBA-related inbred strains were separated from one another (Bailey, 1978; Zylstra et al., 2003). DBA/2J is the only strain with the G>A missense mutation in Fscn2; this mutation occurred sometime between 1951 and 1975, as deduced from archived DNA samples of DBA/2J strain mice. d , Molecular model of FSCN1 (Protein Databank Structure 1DFC) showing the β-trefoil domains (1–4), the regulatory phosphorylation target S39, and the predicted location of the R109 residue of FSCN2 (R110 in FSCN1) that is mutated in DBA/2J mice. e , Hearing loss in F2 intercross progeny of (DBA/2J × DBA/2NCrl) F1 hybrids strongly associates with homozygosity for the DBA/2J allele of Fscn2. Shown are the average 16 kHz ABR thresholds and SEs for each of the three Fscn2 genotypes of F2 mice: D2J/D2J (homozygous for the DBA/2J mutation, n = 9), D2J/D2NCrl (heterozygous for the mutation, n = 7), and D2NCrl/D2NCrl (homozygous for the wild-type DBA/2NCrl allele, n = 5), all tested at 6 weeks of age. The DBA/2J mutant allele appears recessive to the DBA/2NCrl wild-type allele. Image published in: Shin JB et al. (2010) Copyright © 2010. This image is reproduced with permission of the publisher and the copyright holder. This is an Open Access article distributed under the terms of the Creative Commons Attribution License. Larger Image Printer Friendly View

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