The mammalian ovary is a dynamic organ undergoing continuous structural and functional remodeling. This process is especially evident during the estrous cycle, which consists of four distinct phases: proestrus, estrus, diestrus, and anestrus. Each phase is characterized by specific endocrine profiles and histological changes that are crucial for follicular development, ovulation, and the formation and regression of the corpus luteum [1,2]. Before these cyclic events begin, the prepubertal period represents a critical developmental window in which the ovary establishes its structural and molecular framework for future reproductive activity [[3], [4], [5], [6]]. Investigating these maturation processes in parallel with the cyclic stages provides a more integrated view of ovarian physiology and remodeling across developmental and functional transitions.

Recent research has increasingly focused on defining the molecular mechanisms involved in ovarian tissue remodeling. Among the key molecules implicated in these processes are the fibroblast growth factor receptor 3 (FGFR3), the C-X-C chemokine receptor type 4 (CXCR4), and the integrin beta-1 (ITGB1). These molecules are involved in fundamental cellular events, including proliferation, adhesion, migration, and interactions with the extracellular matrix—functions that are critical for maintaining ovarian architecture and function across different physiological states [7,8].

FGFR3 is a transmembrane receptor tyrosine kinase that regulates multiple signaling pathways involved in tissue growth and differentiation, as well as epithelial-mesenchymal interactions that support local tissue homeostasis [9]. CXCR4, a G-protein-coupled receptor, mediates cell migration in response to gradients of its ligand stromal-derived factor 1 (SDF-1/CXCL12). This signaling axis has been implicated not only in the trafficking of progenitor cell populations but also in the broader regulation of tissue remodeling within the ovarian microenvironment [10,11]. ITGB1, a widely expressed cell adhesion molecule, plays a central role in cell–extracellular matrix interactions, influencing cell anchorage, migration, and survival—all of which are vital for the structural integrity and coordinated remodeling of ovarian tissue [12,13].

Despite advancements in reproductive biology, data on the expression of these remodeling-associated markers in the canine ovary remain scarce [14]. Most available studies focus on rodent or human ovarian physiology, with limited information on how these markers are expressed across the estrous cycle in dogs [15]. Furthermore, their distribution during the prepubertal stage—when key developmental processes occur—has received little attention, despite its potential relevance for understanding the molecular basis of ovarian maturation [6].

To address these gaps, the present study aimed to characterize the expression patterns of fibroblast growth factor receptor 3 (FGFR3), C-X-C chemokine receptor type 4 (CXCR4), and integrin beta-1 (ITGB1) in the canine ovary during both the prepubertal stage and the distinct phases of the estrous cycle. Using immunofluorescence staining and histological analysis, we sought to map the localization of these markers and evaluate their potential relationship to cyclic and developmental remodeling processes.