20.500.12556/RUL-180412 Retention of embryonic positional identity signatures in the adult sheep tail evidence from HOXB13 spatial RNA expression gradients Body axis patterning in vertebrates is controlled by HOX genes during embryogenesis, with their expression gradients defining spatial identity along the anterior–posterior axis. While the developmental roles of HOX genes in axial patterning are well established, it remains unclear to what extent embryonically defined anterior–posterior HOX expression patterns are retained as transcriptional signatures in adult tissues. Tail length in sheep provides a model for studying the phenotypic effects of HOX gene variants. We used Improved Jezersko–Solčava sheep, which segregate for both tail length and HOXB13 promoter variants, to examine genotype– phenotype associations. The HOXB13 genotype was the main determinant of adult tail length, acting primarily by modulating caudal vertebral number. RNA‑seq and qPCR analyses revealed a clear anterior–posterior HOXB13 expression gradient in adult tail skin and bones, consistent with retained positional patterning, with stronger distal expression in short‑tailed animals. These results provide in vivo evidence that spatially patterned HOX gene expression is retained in adulthood, consistent with residual transcriptional signatures of embryonic anterior–posterior identity. HOXB13 postnatal spatial gene expression sheep tail length skin and bone RNAseq positional identity ovce lastnosti zunanjosti dolžina repa fenotip genetika geni HOX true false true Angleški jezik Slovenski jezik Članek v reviji 2026-03-09 10:07:14 2026-03-09 10:07:20 2026-04-13 04:41:20 0000-00-00 00:00:00 2026 0 0 17 str. article no. 11776 [Vol.] 16 2026 0000-00-00 Zaloznikova Objavljeno apc 0000-00-00 0000-00-00 2026-03-02 636.3:575 2045-2322 10.1038/s41598-026-42438-7 270214403 RAZ_Horvat_Simon_2026.pdf RAZ_Horvat_Simon_2026.pdf 1 432EEFA32A2B0043DD3B8C1E1C2A7D1D 83bd224752620235e544d211ad1d86c52e4b6551cfcf6dbeca100d0ffc63b087 e0120ab1-34ae-11f1-b0ab-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=232182 https://www.nature.com/articles/s41598-026-42438-7 0 ef99123b-34ae-11f1-b0ab-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=232183 Biotehniška fakulteta 0 0 0