REVISTA CIENTIFICA-FACULTAD DE CIENCIAS VETERINARIAS, cilt.36, sa.1, ss.1-8, 2026 (SCI-Expanded, Scopus)
The Growth Differentiation Factor 8 is a member of the Transforming Growth Factor Beta family and plays a vital role in ovarian dynamics. The present study investigated: i) the expression patterns of Growth Differentiation Factor 8 protein in feline ovarian follicles and corpus luteum, and ii) the effect of reproductive cycle stages on ovarian GDF8 expression in domestic cats. Ovaries were collected from 28 healthy domestic female cats undergoing elective ovariohysterectomy and classified into follicular (n = 15) and luteal (n = 13) phase groups. Growth Differentiation Factor 8 protein expression was assessed via enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry. In primordial follicles, Growth Differentiation Factor 8 immunoreactivity was restricted to the oocyte. In primary and secondary follicles, both oocytes and granulosa cells exhibited Growth Differentiation Factor 8 staining, while thecal cells remained negative. In antral follicles, Growth Differentiation Factor 8 was present in oocytes, granulosa cells, and follicular fluid, but absent in thecal cells. In the corpus luteum, Growth Differentiation Factor 8 immunoreactivity varied by developmental stage. Mild staining was observed in luteal cells during early development and maintenance. Severe immunoreactivity appeared in late developmental and maintenance stages, while moderate staining was present during regression. Non-steroidogenic cells showed no reactivity. No significant differences in ovarian Growth Differentiation Factor 8 expression were found between follicular and luteal phases, nor between maintenance and regression stages of the corpus luteum. Growth Differentiation Factor 8 may significantly regulate folliculogenesis and corpus luteum development in the feline ovary.