Fig. 3: Spine number and DS3 length are associated with the HOXDB locus in Apeltes.
From: Evolution of stickleback spines through independent cis-regulatory changes at HOXDB
a, X-rays of Apeltes quadracus from Louisbourg Fortress with 3–6 dorsal spines. Scale bar, 5 mm. b, Association mapping of Apeltes from Louisbourg Fortress (n = 211) and Tidnish River 3 (n = 121). Both populations show a significant association between spine number and the HOXDB locus. Apeltes from Louisbourg Fortress were also phenotyped for dorsal spine length and showed a significant association between DS3 length and the HOXDB cluster. The markers used are displayed across the top (1–12) and the peak marker (6) is highlighted in red. The dotted line represents the Bonferroni-corrected significance threshold at α = 0.05. The 95% confidence intervals (CIs) (2-LOD) for spine number are denoted by the bars at the bottom (grey for Louisbourg, black for Tidnish). The overlapping 95% CI for spine number is approximately 5,750 bp from the third exon of HOXD11B to the first exon of HOXD9B. The smallest interval shared by both spine number and spine length intervals is approximately 2 kb, including HOXD11B exon 3 and part of the intergenic region between HOXD9B and HOXD11B. Additional anatomical details and association plots for other spine lengths are shown in Extended Data Fig. 7.
