Proteomic analysis of fetal skin by iTRAQ reveals molecular signals underlying Inner Mongolia Cashmere goat hair follicle initiation

Abstract

Cashmere goats produce wool from primary hair follicles (PHF)and cashmere from secondary hair follicles(SHF). Numerous genetic factors have been identified to affect HF formation, but the mechanism that controls the distinct morphogenesis of PHFs and SHFs remains unclear. To better describe goat’s hair follicle proteome, we applied iTRAQ technology to study protein expression profiling from nine skin samples of cashmere goats in three fetal periods including 45-day-old embryos (E45), 55-day-old embryos (E55), 65-day-old embryos (E65). A total of 1172 proteins identified are expressed in fetal skin. The numbers of differentially expressed proteins in E45 vs. E55, E45 vs. E65, and E55 vs. E65 were 103, 144, and 118, respectively. Sixty-three proteins were constantly increased through the whole embryonic developmental stages of placode formation. Keratin 1, 4, 5, 10, 13, 15, 17, and 75 belonging to the hair keratin family (KRTs) were identified during keratinocyte proliferation. Some proteins involved in these pathways probably have a role in the HF and might be the mediators of HF initiation in Cashmere goats. Our systematic investigation identified some signaling factors that drive the large-scale cellular rearrangements necessary for HF initiation, which provide an insight into the fundamental mechanisms of cashmere growth.