The Distribution of Melanocytes and the Degradation of Melanosomes in Fetal Hair Follicles

The study investigated the distribution and degradation of melanocytes and melanosomes in fetal hair follicles using a scalp specimen from a 5-month gestational age fetus. It found that melanocytes in different regions of fetal hair follicles had varied morphologies and differentiation stages, primarily located along the outer root sheath and at the bottom of hair bulbs. Transmission electron microscopy revealed melanocytes containing melanosomes at all developmental stages, with some containing autophagosomes. Melanosomes were degraded into irregular pigment particles within phagolysosomes of cortical keratinocytes. The study suggested that oxidative reactions might contribute to the complete biodegradation of melanosomes, providing insights into the mechanisms of melanosome biodegradation in fetal hair follicles.