Rong Ma

The development of secondary hair follicles in cashmere goats directly influences the yield and quality of cashmere, and hair follicle morphogenesis is a complex biological process involving multiple signaling pathways and regulatory factors. In recent years, the regulatory role of long non-coding RNAs in hair follicle development has gradually been uncovered. Based on a previously established transcriptome database of embryonic skin tissue from cashmere goats, this study ultimately identified lncRNA MRPS28, which exhibits significant differential expression during the morphogenesis of secondary hair follicles. Our results indicate that lncRNA MRPS28 is a non-coding RNA transcribed from the intron region of the MRPS28 gene. Additionally, it can inhibit the proliferation and migration of dermal fibroblasts while promoting their apoptosis. Further mechanistic studies have shown that lncRNA MRPS28 acts as a competing endogenous RNA, sponging chi-miR-145-5p, thereby relieving its inhibitory effect on the target gene NUAK1. This, in turn, inhibits the formation of dermal papilla structures and ultimately affects the morphogenesis of secondary hair follicles during the embryonic period. This study provides a novel perspective on dissecting the regulatory network of hair follicle development in cashmere goats and offers potential theoretical insights for breeding new strains of cashmere goats.

Background: The cashmere goat is a biological resource that mainly produces cashmere. Cashmere has a soft hand feel and good luster, with high economic value. The quality and yield of cashmere are determined by the process of hair follicle development during the embryonic period. Methods: In this study, the skin of the Inner Mongolia cashmere goat at different embryonic stages (45, 55, 65, and 75d) was collected, and the differentially expressed lncRNA MSTRG.20890.1 at 75d was obtained by screening. Dual luciferase reporter gene system, qRT-PCR, and EDU experiments were used to verify further the regulatory role and molecular mechanism of the lncRNA in dermal fibroblasts. Results: Based on the transcriptome database of Inner Mongolia cashmere goat skin at different embryonic stages, which was previously constructed by our group, according to the characteristics of hair follicle development in the embryonic stage, we screened out the lncRNA MSTRG.20890.1 that was down-expressed on the 75-SHFINI day of the embryonic stage. We found that lncRNA MSTRG.20890.1 was mainly located in the cytoplasm of cells, and it could inhibit the proliferation and directional migration of dermal fibroblasts through the chi-miR-24-3p/ADAMTS3 signaling axis, thereby inhibiting the formation of dermal papilla structure at embryonic stage. Conclusions: This study revealed that lncRNA MSTRG.20890.1 regulated secondary hair follicle morphogenesis and development in cashmere goats through the chi-miR-24-3p/ADAMTS3 signaling axis.