The restoration of lost tissue to its original form, also called epimorphic regeneration, occurs in certain vertebrates, including teleost fish such as zebrafish. Zebrafish can regenerate lost elasmoid scales within days, making them a valuable model for studying vertebrate morphogenesis. These thin, transparent scales consist of a bone matrix surrounded by diverse cell types, notably osteoblasts, which are central to the regenerative process. Osteoblasts regenerate the scale through a sequence of de novo differentiation, proliferation and hypertrophy. While the spatial pattern of proliferation during regeneration is known, the mechanism that triggers osteoblast maturation and proliferation arrest remains unclear. This study investigates expression of the gene fgfr3 as a potential marker for proliferative osteoblasts and explores a hypothesis in which bone matrix growth disrupts signalling between osteoblast layers, thereby initiating maturation. We used live imaging and single-molecule fluorescence in situ hybridisation (smFISH) to analyse respectively fgfr3 expression and candidate signalling molecules. Because no smFISH protocols were previously designed for dissected fish flanks, an adapted protocol was established. Our results show that fgfr3 expression exhibits a spatial distribution aligned with proliferative zones and is inversely correlated with the presence of bone matrix. Although gene expression of the four tested candidates shows interesting patterns, none of them supported the hypothesis that communication from the episquamal to the hyposquamal layer is interrupted by bone growth. These findings establish patterns of gene expression at the transition of osteoblast proliferation to maturity, although the precise role of the bone matrix in this process remains to be elucidated.