Due to recent innovations in gene editing technology, great progress has been made in livestock breeding, with researchers rearing gene-edited pigs, cattle, sheep, and other livestock. Gene-editing technology involves knocking in, knocking out, deleting, inhibiting, activating, or replacing specific bases of DNA or RNA sequences at the genome level for accurate modification, and such processes can edit genes at a fixed point without needing DNA templates. In recent years, although clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system-mediated gene-editing technology has been widely used in research into the genetic breeding of animals, the system’s efficiency at inserting foreign genes is not high enough, and there are certain off-target effects; thus, it is not appropriate for use in the genome editing of large livestock such as cashmere goats. In this study, the development status, associated challenges, application prospects, and future prospects of CRISPR/Cas9-mediated precision gene-editing technology for use in livestock breeding were reviewed to provide a theoretical reference for livestock gene function analysis, genetic improvement, and livestock breeding that account for characteristics of local economies.

Background: Melatonin is an important regulator of seasonal hair follicle activity in Inner Mongolia cashmere goats, but the miRNA-mediated mechanisms linking melatonin signaling to dermal papilla cell (DPC) function remain incompletely understood. In the present study, we examined the role of chi-miR-27a-3p in melatonin-treated DPCs. Methods: DPCs were isolated from Inner Mongolia cashmere goats and treated with melatonin or transduced with lentiviral constructs for chi-miR-27a-3p knockdown or overexpression. Cell proliferation was assessed by CCK8 and Ki67 immunofluorescence, cell-cycle distribution and apoptosis by flow cytometry, and the chi-miR-27a-3p–Wnt7B interaction by dual-luciferase reporter assay; the expression of Wnt7B, Wnt10b, β-catenin, SFRP1 and DKK1 was measured by qRT-PCR and Western blotting. Results: Melatonin treatment was accompanied by downregulation of chi-miR-27a-3p. Chi-miR-27a-3p overexpression reduced DPC proliferation and increased apoptosis, whereas its inhibition increased CCK-8 signal and promoted cell-cycle progression while reducing apoptosis; Ki67 fluorescence was not significantly changed in the knockdown group. Dual-luciferase assays showed that chi-miR-27a-3p directly targets the Wnt7B 3′-UTR in a sequence-dependent manner, and chi-miR-27a-3p manipulation was accompanied by reciprocal changes in Wnt7B, Wnt10b, β-catenin, SFRP1 and DKK1 expression. Conclusions: These findings support a potential regulatory relationship between melatonin, chi-miR-27a-3p and Wnt7B in DPCs; however, whether chi-miR-27a-3p is required for melatonin-induced proliferation and whether Wnt7B mediates its cellular effects require further rescue experiments and in vivo validation.