Background: Cashmere goats make an outstanding contribution to the livestock textile industry and their cashmere is famous for its slenderness and softness and has been extensively studied. However, there are few reports on the molecular regulatory mechanisms of the secondary hair follicle growth cycle in cashmere goats. In order to explore the regular transition through the follicle cycle and the role of key genes in this cycle, we used a transcriptome sequencing technique to sequence the skin of Inner Mongolian cashmere goats during different months. We analyzed the variation and difference in genes throughout the whole hair follicle cycle. We then verified the regulatory mechanism of the cashmere goat secondary hair follicle growth cycle using fluorescence quantitative PCR. Results: The growth cycle of cashmere hair could be divided into three distinct periods: a growth period (March–September), a regression period (September–December), and a resting period (December–March). The results of differential gene analyses showed that March was the most significant month. Cluster analysis of gene expression throughout the whole growth cycle further supported the key nodes of the three periods of cashmere growth, and the differential gene expression of keratin corresponding to the ground haircashmere growth cycle further supported the results from tissue slices. Quantitative fluorescence analysis showed that KAP3–1, KRTAP 8–1, and KRTAP 24–1 genes had close positive correlation with the cashmere growth cycle, and their regulation was consistent with the growth cycle of cashmere. Conclusion: The growth cycle of cashmere cashmere could be divided into three distinct periods: a growth period (March–September), a regression period (September–December) and a resting period (December–March). March was considered to be the beginning of the cycle. KAP and KRTAP showed close positive correlation with the growth cycle of secondary hair follicle cashmere growth, and their regulation was consistent with the cashmere growth cycle. But hair follicle development-related genes are expressed earlier than cashmere growth, indicating that cycle regulation could alter the temporal growth of cashmere. This study laid a theoretical foundation for the study of the cashmere development cycle and provided evidence for key genes during transition through the cashmere cycle. Our study provides a theoretical basis for cashmere goat breeding.

The traditional breeding industry has been increasingly saturated and caused environmental pollution, disease transmission, excessive resource use, and methane emission; however, it still cannot meet the needs of the growing population. To explore other alternatives, researchers focused on cell agriculture and cell-based meat, especially large-scale cell culture. As a prerequisite for production, large-scale culture technology has become an important bottleneck restricting cell-based meat industrialization. In this study, the single-factor variable method was adopted to examine the influence of Cytodex1 microcarrier pretreatment, spinner flask reaction vessel, cell culture medium, serum and cell incubation, and other influencing factors on large-scale cell cultures to identify the optimization parameters suitable for 3D culture environment. Collagen and 3D culture were also prospectively explored to promote myogenesis and cultivate tissue-like muscle fibers that contract spontaneously. This research lays a theoretical foundation and an exploratory practice for large-scale cell cultures and provides a study reference for the microenvironment of myoblast culture in vitro, a feasible direction for the cell therapy of muscular dystrophy, and prerequisites for the industrialized manufacturing of cell-based meat. Graphical

Background: Horn development is a key ruminant trait involving multi-cell type coordination via molecular pathways. This study used scRNA-seq to analyze cellular heterogeneity and fate trajectories during early horn bud niche formation, revealing key gene expression profiles. Combining with hematoxylin–eosin (HE) staining and immunohistochemical analysis, we further verified the asynchronous developmental pathways of key cells in the skin tissue of fetal goat horn bud at induction (embryonic day (E) 50; E50), organogenesis (E60), and cytodifferentiation (E70) stages, and demonstrated the signal transmission routes for the development of early horn buds. Results: We revealed temporal and spatial differences of the main signal transmission of horn bud development combining with existing literatures. We speculated that multiple cell types under the guidance of nerve cells collaborated on horn bud initiation in dairy goats. In detail, neural cells receive initial horn bud signals, stimulating hair follicle cell degeneration and transmitting to dermal cells, which evolve through intermediates, amplify signals to epithelial cells, and differentiate into mesenchymal cells. Nerve cell branches also trigger neural crest cell production/migration, working with chondrocytes to promote keratinocyte differentiation for horn bud formation. In addition, we further identified the early horn bud developmental specific events, including the screening of biological functions, signaling pathways and key candidate genes. Conclusions: This study employed scRNA-seq to characterize cell fate trajectories and gene expression profiles in goat fetal horn buds. Histological comparisons between hornless and horned fetuses revealed cellular heterogeneity in epithelial, dermal, nerve, and hair follicle cells, with pseudo-time analysis identifying distinct differentiation paths. Dermal and epithelial cell transcriptional dynamics were critical for horn bud initiation (branch 1), supported by immunohistochemistry. Keratinocyte and nerve cell state transitions actively regulated horn development, with asynchronous cell development visualized via immunohistochemistry. Functional enrichment analyses (GO/KEGG) highlighted neural crest development and keratinocyte differentiation pathways, identifying candidate genes ( EGR1 , ZEB2 , SFRP2 , KRT10 , FMOD , CENPW , LDB1 , TWIST1 ) involved in horn morphogenesis. These findings advance understanding of goat horn development and genetic determinants.

Cashmere goats, as an important part of animal husbandry production, make outstanding contributions to animal fiber industry. In recent years, a great deal of research has been done on the molecular regulation mechanism of hair follicle cycle growth. However, there are few reports on the molecular regulation mechanisms of secondary hair follicle growth cycle in cashmere goats. In this study, we used transcriptome sequencing technique to sequence the skin of Inner Mongolia cashmere goats in different periods, Analyze the variation and difference of genes in the whole hair follicle cycle. And then, we verified the regulation mechanism of cashmere goat secondary hair follicle growth cycle by fluorescence quantitative PCR. As the result shows: The results of tissue section showed that the growth cycle of cashmere hair could be divided into three distinct periods: growth period (March-September), regression period (September-December) and resting period (December-March). The results of differential gene analysis showed that March was considered the beginning of the cycle, and the difference of gene expression was the most significant. Cluster analysis of gene expression in the whole growth cycle further supported the key nodes of the three periods of villus growth, and the differential gene expression of keratin corresponding to the villus growth cycle further supported the results of tissue slices. Quantitative fluorescence analysis showed that KAP3.1, KRTAP 8-1 and KRTAP 24-1 genes had close positive correlation with the growth cycle of cashmere, and their regulation was consistent with the growth cycle of cashmere. However, there was a sequence of expression time, indicating that the results of cycle regulation made the growth of cashmere change.