A Hidden RNA Switch May Shape Cashmere Goat Hair Follicles Before Birth

Deep inside the skin of embryonic cashmere goats, at a precise window of development, a long non-coding RNA molecule appears to flicker into prominence and then fade away. That fleeting burst of activity, reported by a team of Chinese researchers in BMC Genomics, may help orchestrate one of the most economically consequential events in livestock biology: the formation of the hair follicles that will eventually produce cashmere, one of the world’s most luxurious natural fibers. The study, led by Xuxu Bao and colleagues at Inner Mongolia Agricultural University, does not claim to have solved the mystery of follicle morphogenesis, but it assembles an unusually careful chain of evidence pointing to a candidate regulatory circuit involving a poorly understood RNA molecule, a microRNA, and a well-known developmental signaling protein.

The research began with a question of timing. Hair follicles do not simply appear; they arise through a tightly choreographed sequence of interactions between the embryonic epidermis and the underlying dermis, and the genes that drive this process are thought to be active only during narrow developmental windows. To find those windows, the team collected fetal skin from cashmere goats at four gestational stages—days 45, 55, 65, and 75—obtained by cesarean section from does maintained under identical environmental and dietary conditions. Using the same samples as a previously published study, and with approval from the Laboratory Animal Ethics Committee of Inner Mongolia Agricultural University, they profiled gene expression across these stages and searched for long non-coding RNAs whose behavior changed in a stage-specific, transient manner.

Long non-coding RNAs, or lncRNAs, are transcripts that do not code for proteins but can regulate gene expression in a variety of ways. Some act inside the nucleus, scaffolding chromatin complexes; others linger in the cytoplasm, where they can interact with microRNAs. The screen identified 32 candidate lncRNAs with transient, stage-specific expression changes at embryonic day 55, a finding that suggests this single day may represent an important hub of transcriptional regulation during follicle morphogenesis. Enrichment analysis of the accompanying gene expression data showed positive enrichment of Wnt-related gene sets in the day 55 versus day 45 comparison and in the day 65 versus day 55 comparison. The authors are careful to note that this enrichment does not constitute a direct measurement of Wnt pathway activity, but it places the day 55 window squarely in the territory of one of developmental biology’s most celebrated signaling systems.

Among the 32 candidates, one transcript stood out. Known by the unglamorous identifier MSTRG.18075.2, this lncRNA showed relatively high expression at embryonic day 55, exactly the stage flagged by the temporal screen. Subcellular localization experiments revealed that the molecule resides predominantly in the cytoplasm—a detail that matters enormously for what the researchers proposed next. Cytoplasmic lncRNAs are the raw material of one of molecular biology’s most debated regulatory models: the competing endogenous RNA, or ceRNA, hypothesis. In this model, a lncRNA acts as a molecular sponge, soaking up microRNAs that would otherwise bind to and suppress messenger RNAs. By titrating microRNAs away from their targets, the lncRNA indirectly protects those targets, effectively adding a layer of cross-talk between transcripts that never touch each other physically.

The microRNA at the center of the proposed circuit is chi-miR-145-5p, and the target is WNT16, a member of the Wnt family of secreted signaling proteins that play fundamental roles in embryonic patterning, including the initiation and development of hair follicles. The team first tested the predicted interactions in a heterologous reporter system using 293T cells, a standard laboratory workhorse derived from human embryonic kidney tissue. When chi-miR-145-5p was introduced, it reduced the activity of wild-type reporter constructs containing the predicted binding sites from either MSTRG.18075.2 or the 3′ untranslated region of WNT16. Crucially, mutant reporters in which those binding sites were disrupted did not show the same response. That pattern—suppression of the wild-type sequence but not the mutated one—is the classic signature of a sequence-specific microRNA interaction, and it lent credibility to the predicted pairing on both ends of the proposed axis.

Reporter assays, however, are performed in a foreign cellular context, and the authors acknowledge this limitation explicitly. The more biologically meaningful experiments took place in cashmere goat dermal fibroblasts, the dermal cells that provide the structural and signaling environment in which follicles form. When the researchers knocked down MSTRG.18075.2 in these cells, a coherent set of phenotypes emerged: apoptosis was reduced, cell-cycle progression slowed, proliferation and migration were impaired, and intracellular reactive oxygen species accumulated. Each of these cellular behaviors is relevant to morphogenesis, because follicle development requires precisely timed waves of cell proliferation, movement, and survival in the dermal compartment. A transcript whose perturbation disturbs all of these processes simultaneously is a plausible participant in the developmental program, even if the exact in vivo role remains unproven.

The genetic logic of the ceRNA model makes a specific prediction: if MSTRG.18075.2 protects WNT16 by soaking up chi-miR-145-5p, then removing the microRNA should partially rescue the effects of removing the lncRNA. That is essentially what the team observed. Combined knockdown of chi-miR-145-5p partially reversed some of the phenotypes induced by knocking down either MSTRG.18075.2 or WNT16. The rescue was partial, not complete, which is consistent with the messy reality of cellular networks—microRNA-145-5p almost certainly has other targets, and MSTRG.18075.2 may have other functions—but the direction of the effect supports the candidate regulatory model the authors propose: MSTRG.18075.2 sponges chi-miR-145-5p, thereby relieving repression of WNT16.

To their credit, the researchers draw the boundaries of their claims with unusual precision. They note that endogenous RNA complexes were not examined, that downstream Wnt signaling activity was not directly measured, and that no experiments tested whether the axis influences hair follicle morphogenesis in living embryos. The findings, they write, support a relationship between MSTRG.18075.2 and the candidate chi-miR-145-5p/WNT16 axis at the levels of temporal expression, cytoplasmic localization, sequence-specific reporter responses, and in vitro cellular phenotypes—but they do not directly establish an endogenous ceRNA mechanism or a causal relationship in vivo. In a field where the ceRNA hypothesis has been criticized for overreach, this restraint is notable and strengthens rather than weakens the study’s contribution.

The broader significance of the work lies in what it offers for the future of cashmere production. Cashmere goats are the economic backbone of many herding communities in Inner Mongolia, and the fineness and density of the undercoat fibers they produce are determined largely by the number and quality of secondary hair follicles established during embryonic development. If regulatory circuits like the one described here can be confirmed in vivo, they could eventually inform selective breeding strategies or even molecular interventions aimed at improving fiber yield and quality. The study was supported by the Inner Mongolia Autonomous Region Science and Technology Program and the Innovative Research Team Program for Higher Education Institutions of Inner Mongolia Autonomous Region, reflecting regional investment in the genetics of this prized livestock resource.

For now, MSTRG.18075.2 remains a candidate rather than a confirmed conductor of follicle development, and the day 55 window it marks is a lead rather than a conclusion. But the study exemplifies a productive middle path in modern genomics: a temporal screen to find the moment, localization studies to find the compartment, reporter assays to test the chemistry, and cell-based phenotyping to test the biology. Each step alone would be suggestive; together they form a coherent, testable hypothesis about how a non-coding transcript in the cytoplasm of embryonic skin cells might help decide how many follicles a future goat will grow. The next chapter—demonstrating the mechanism inside the developing follicle itself—will be the one that determines whether this molecular whisper becomes a roar.

Subject of Research: A candidate lncRNA/microRNA/WNT16 regulatory axis in embryonic hair follicle development of cashmere goats

Article Title: Cytoplasmic lncRNA MSTRG.18075.2 associated with embryonic hair follicle development in cashmere goats: dermal fibroblast phenotypes and a candidate chi-miR-145-5p/WNT16 regulatory axis

Article References: Bao, X., Ma, R., Pan, J., Wang, Y., Qiao, J., Ma, Q., Wang, R., Shang, F., & Zhang, Y. (2026). Cytoplasmic lncRNA MSTRG.18075.2 associated with embryonic hair follicle development in cashmere goats: dermal fibroblast phenotypes and a candidate chi-miR-145-5p/WNT16 regulatory axis. BMC Genomics. https://doi.org/10.1186/s12864-026-13305-6

Image Credits: AI Generated

DOI: 10.1186/s12864-026-13305-6

Keywords: cashmere goat, lncRNA, MSTRG.18075.2, chi-miR-145-5p, WNT16, ceRNA, hair follicle morphogenesis, dermal fibroblasts, Wnt signaling, embryonic development, BMC Genomics, Inner Mongolia