Evaluation of ovarian remodeling-associated markers across prepubertal and adult cyclic stages in the dog.

This study investigated the expression of three ovarian remodeling-associated markers, fibroblast growth factor receptor 3 (FGFR3), C-X-C chemokine receptor type 4 (CXCR4), and integrin beta-1 (ITGB1) in the canine ovary across both the prepubertal stage and the distinct phases of the estrous cycle. Ovarian tissues were obtained from 50 dogs (n = 10 per group: prepubertal, proestrus, estrus, diestrus, and anestrus) and analyzed using hematoxylin and eosin staining to confirm stage-specific ovarian morphology, alongside immunofluorescence to evaluate marker localization. FGFR3 immunoreactivity in granulosa cells progressively increased from prepuberty to estrus (p < 0.05) but declined sharply in anestrus (p < 0.0001). CXCR4 showed stage-dependent variation, with interstitial cell expression peaking in proestrus (p < 0.05) and luteal positivity restricted to diestrus (p < 0.01 vs. anestrus). ITGB1 was already detectable in prepubertal ovaries and broadly expressed across compartments, including oocytes in diestrus, but decreased significantly in anestrus compared with proestrus (p < 0.05) and estrus (p < 0.01). These results demonstrate that FGFR3, CXCR4, and ITGB1 display stage and cell-type-specific expression in the canine ovary, with baseline expression already evident in prepubertal tissue. Collectively, the findings underscore the involvement of growth factor, chemokine, and integrin pathways in follicular growth, luteal function, and ovarian quiescence, providing novel insights into canine reproductive biology and offering comparative perspectives for ovarian physiology in other species.