miR-200a Targets PITX2 to Mediate Goose Fibroblast Proliferation Through the Wnt Pathway

The economic value of goose down is attributed to its extensive application in the production of down-based clothing and related products. The primordium formation stage governs the proper morphogenesis of the feather follicle, while the Wnt signaling pathway serves a positive regulatory function during this stage. To identify critical miRNAs and molecular mechanisms regulating the development of goose feather follicle primordium, we performed transcriptomic sequencing of skin tissues collected from six geese at pre- and post-feather follicle primordium developmental stages. Bioinformatics analysis identified 350 differentially expressed miRNAs (DE miRNAs), which were functionally enriched in processes related to system development and multicellular organismal development, etc. As demonstrated by dual-luciferase reporter experiments, miR-200a binds directly to PITX2's 3' untranslated region (3'UTR). Furthermore, overexpression of miR-200a decreased the expression levels of genes linked to the Wnt pathway and suppressed the proliferation of GEDFs, as validated by RT-qPCR, CCK8, and EdU assays. Notably, co-transfection experiments demonstrated that miR-200a-mediated regulation of GEDF proliferation through the Wnt pathway is functionally dependent on PITX2. Collectively, this work expands the regulatory network underlying feather follicle development and provides a genetic foundation aimed at breeding geese with enhanced down production quality.