Figure 1: Mapping of coronary flow to the rat 2q34 locus and identification of Wars2 as the candidate gene at the locus. | Nature Communications

Figure 1: Mapping of coronary flow to the rat 2q34 locus and identification of Wars2 as the candidate gene at the locus.

From: Wars2 is a determinant of angiogenesis

Figure 1

(a) Coronary flow (CF) under intrinsic heart rate conditions in the Brown Norway (BN) and Spontaneously Hypertensive rat (SHR) (left panel, n=12) and under cardiac pacing conditions (right panel, n=20). (b) Genome-wide Evolutionary Stochastic Search (ESS) mapping17 of CF at three distinct experimental time points in an F2 cross (n=172) between the SHR and BN strains (x axis, rat autosomes; posterior probabilities for the peak SNP shown). (c) Replication of the CF QTL by congenic rescue in an SHR strain (SHR.BN2q34) encoding the BN genotype at the CF locus (P=3.2 × 10−6; n=6, SHR and 8, congenic; two-way analysis of variance (ANOVA) with Tukey's multiple comparisons test). (d) Capillary density (shown in arbitrary optical units) in the heart in SHR.BN2q34 strain (n=8) and the parental SHR (n=6) strain. (e) Capillary density (shown in arbitrary optical units) in F2 rats by BN/SHR genotype of the peak-associated SNP (n=10–16 per genotype). One-way ANOVA with Tukey’s multiple comparisons test. (f) Refinement of the 2q34 locus using flanking markers to the QTL (Chromosome 2: 189.3 Mb and 194.5 Mb) and all protein damaging variation at the locus in SHR, Salt Sensitive (SS) or Fawn Hooded Hypertensive (FHH) rats (black squares; grey squares, no variation). (g) Candidate gene prioritization using BN, SHR, SS and FHH whole-genome sequences and PolyPhen2 prediction of protein damaging variants effect (y-axis) from (f). Grey dashed lines indicate physical position of genes. (h) Sequence alignments of Wars2(L53F) protein variation in the ‘HXGH motif’19 in the SHR, the BN rat and other species (zebrafish, ZFish). (i) Western blot of wild-type WARS2 and WARS2(L53F) protein. Arrows indicate WARS2- specific immunoreactive band (upper arrow, high molecular weight isoform; lower arrow, low molecular weight isoform); bottom panel, GAPDH immunoblot as loading control. (j) In vitro assay of canonical enzymatic activities (arbitrary optical units) of WARS2 and WARS2(L53F) (red line, mean). t-test: *P<0.05; ***P<0.001.

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