Figure 2.

The coding region of the Atp5a1 gene contains a 4-bp insertion. (A) Results of the real-time PCR analysis of intestinal expression of Atp5a1 and 8030462N17Rik expression in B6, DBA, and DBA.Mom2^R/+ congenic mice. A graphical representation of the relative expression levels of Atp5a1 and 8030462N17Rik in the proximal small intestine, distal small intestine, and colon are shown. Experimentally determined expression levels in wild-type B6, wild-type DBA, and the Mom2^R/+ congenic are shown. The predicted WT bar indicates the expected expression level in the Mom2^R/+ congenic animal, assuming 50% contribution from both parental alleles. Atp5a1 reproducibly demonstrated an expression of 50% of the DBA/2J allele, with no contribution from the B6 allele. 8030462N17Rik was representative of the other genes that mapped to the congenic interval, demonstrating an expression level equivalent to the predicted level (Supplemental Methods 1). (B) The sequence of exon 3 of the Atp5a1 gene in a Mom2^R/+ mouse reveals a divergence beginning after the 100^th nucleotide of exon 3. The mutation is a 4-bp duplication of ATGG (shown in box) within exon 3. (C) The amino acid sequence of the wild-type Atp5a1 gene is shown in comparison to the amino acid sequence of the mutant Atp5a1^Mom2R allele. The 4-bp insertion results in a frameshift that is predicted to generate a severely truncated protein.