MThe spatial expression of gelatinases in bovine and swine follicles probably reflects the distinct role of each enzyme in the physiological events of ovarian development (Basini et al. 2011). In this study, we have determined the expression pattern of the two key gelatinases MMP-9, which is involved in cell growth, and MMP-2, which is associated with cellular reorganization during follicle development and have compared the differences in MMP and TIMP expression between normal and miniature pigs. Our results show that during folliculogenesis, distinct types of MMPs and TIMPs are expressed in the ovaries of normal and miniature pigs. We believe that the differential expression of MMPs and TIMPs in these breeds may provide an insight into the molecular basis of reduced fertility in miniature pigs.