Expression of Transforming Growth Factor-Beta (TGF-Beta 1) and Insulin-Like Growth Factor II (IGF-II) Messenger RNA in the Developing Subcutaneous Tissue of the Fetal Pig

The study investigated the expression of TGF-beta 1 and IGF-II mRNA in the developing subcutaneous tissue of pig fetuses and postnatal pigs using in situ hybridization. TGF-beta 1 mRNA was primarily found in the dermis, hair follicle fat lobule, and subcutaneous areas across all ages, particularly near adipocyte clusters. In contrast, IGF-II mRNA was initially expressed in the developing muscle below the subcutaneous tissue at 50 and 70 days, with lower levels at 90 and 110 days, but increased again in the muscle of 7-day-old postnatal pigs. The findings suggested that paracrine and autocrine regulatory systems might regulate developing adipocytes and muscle, with specific spatial and temporal expression patterns of TGF-beta 1 and IGF-II in pig subcutaneous tissue.