The goat breeding industry on the Tibetan Plateau faces strong selection pressure to enhance fertility. Consequently, there is an urgent need to develop goat lines with higher fertility and adaptability. The ovary, as a key organ determining reproductive performance, is regulated by a complex transcriptional network involving numerous protein-coding and non-coding genes. However, the molecular mechanisms of the key mRNA–miRNA–lncRNA regulatory network in goat ovaries remain largely unknown. This study focused on the histology and differential mRNA/miRNA/lncRNA between Chuanzhong black goat (CBG, high productivity, multiple births) and Tibetan goat (TG, strong adaptability, single birth) ovaries. Histomorphological analysis showed that the medulla proportion in CBG ovaries was significantly reduced compared to TG. RNA-Seq and small RNA-Seq analysis identified 1218 differentially expressed (DE) mRNAs, 100 DE miRNAs, and 326 DE lncRNAs, which were mainly enriched in ovarian steroidogenesis, oocyte meiosis, biosynthesis of amino acids and protein digestion, and absorption signaling pathways. Additionally, five key mRNA–miRNA–lncRNA interaction networks regulating goat reproductive performance were identified, including TCL1B–novel68_mature–ENSCHIT00000010023, AKAP6–novel475_mature–ENSCHIT00000003176, GLI2–novel68_mature–XR_001919123.1, ITGB5–novel65_star–TCONS_00013850, and VWA2–novel71_mature–XR_001919911.1. Further analyses showed that these networks mainly affected ovarian function and reproductive performance by regulating biological processes such as germ cell development and oocyte development, which also affected the plateau adaptive capacity of the ovary by participating in the individual immune and metabolic capacities. In conclusion, we identified numerous mRNA–miRNA–lncRNA interaction networks involved in regulating ovarian function and reproductive performance in goats. This discovery offers new insights into the molecular breeding of Tibetan Plateau goats and provides a theoretical foundation for developing new goat lines with high reproductive capacity and strong adaptability to the plateau environment.

The quality of lamb meat is positively correlated with intramuscular fat content. In recent years, a large number of studies have shown that miRNAs play an important role in the proliferation and differentiation of adipocytes. In this study, we aimed to explore the effect of miR-92a-3p on the differentiation of goat intramuscular preadipocytes. The results showed that the expression level of miR-92a-3p was low in the early stage of differentiation, reached the highest level on the third day of differentiation, and then decreased. And miR-92a-3p can inhibit the accumulation of lipid droplets and down-regulate the determinants of adipogenic differentiation. Mechanistically, by predicting target genes, we found that miR-92a-3p affects the differentiation of goat intramuscular preadipocytes and the accumulation of lipid droplets by regulating the expression of goat gene APOL6. This study provides important new information to better understand the relationship between miRNAs and the differentiation of goat intramuscular preadipocytes, thus providing a new reference for goat intramuscular adipogenesis.

Objective: Circular RNAs (circRNAs) are widely involved in the regulation of lipid deposition in animals, but there are few reports on key circRNAs regulating intramuscular adipocyte differentiation in goats. Therefore, this study took an abundantly expressed in goat adipocytes chi-circ_0009659 as the object.Methods: Based on the identification of back splicing site in chi-circ_0009659, its expression level during the goat intramuscular preadipocyte differentiation was detected by quantitative polymerase chain reaction (qPCR) . The chi-circ_0009659 loss-of-function and gain-of-function cell models were obtained by adenovirus and smarter silencer, respectively. and the adipocyte differentiation were explored by Oil Red O staining, Bodipy staining and qPCR. Its major cytoplasmic localization was determined by fluorescence in situ hybridization (FISH), nucleocytoplasmic separation and qPCR. The interaction between chi-circ_0009659, miR-3431-5p, and STEAP family member 4 (STEAP4) was verified by bioinformatics, RNA pull down and dual luciferase reporter assay.Results: Silencing chi-circ_0009659 inhibited lipid droplet accumulation and the expression of differentiation-determining genes in goat intramuscular adipocytes, while overexpression of chi-circ_0009659 reversed these results. chi-circ_0009659 was predominantly localized to the cytoplasm and could regulate miR-3431 expression which in turn affects STEAP4. Consistent with expectations, miR-3431-5p acted as a negative regulator of GIMPA differentiation, while STEAP4 promoted differentiation.Conclusion: We demonstrated chi-circ_0009659 positively regulates goat intramuscular preadipocyte differentiation by sponging miR-3431-5p to further regulate the expression of STEAP4. This research provides a new reference for in-depth understanding of the effects of circRNA on adipocyte differentiation.

The presence or absence of subcutaneous adipose accumulation will affect the energy storage, insulation resistance and metabolism of animals. Proliferation and differentiation of preadipocytes play a significant role in lipid deposition. The objective of this study was to clone the goat CXCL17 gene and investigate its potential functions on goat subcutaneous preadipocytes’ proliferation by gaining or losing function in vitro. The goat CXCL17 gene was cloned by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and bioinformatics analysis was performed. The expression of the CXCL17 gene in the different goat tissues and adipocytes at different differentiation stages was detected by real-time fluorescence quantitative PCR (qPCR). The results showed that the cloned sequence of goat CXCL17 gene is 728 bp and the CDS region is 357 bp, encoding 118 amino acids. CXCL17 protein is located in nucleus, cytoplasm, mitochondria and extracellular matrix. Tissue-expression profiles revealed that CXCL17 expressed in all of the examined tissues. In visceral tissues, the highest expression level was found in lung (p < 0.01); in muscle tissues, the highest CXCL17 expression level was found in the longissimus dorsi (p < 0.01) and in adipose tissues, the highest expression level was found in subcutaneous adipose (p <0.01). Compared with those cells before differentiation, CXCL17 expression levels upregulated at 48 h (p < 0.01), 72 h (p < 0.01), 120 h (p < 0.01) and downregulated at 96 h (p < 0.01). Furthermore, the results of crystal violet staining and semi-quantitative assay showed that transfection with 1 μg CXCL17 expression plasmid reduced the cell numbers in vitro. Meanwhile, the expression of CCND1 was significantly decreased. A similar consequence happened after interfering with CXCL17 expression. However, plasmid transfected with 2 μg pEGFPN1-CXCL17 increased the number of cells in vitro. These results suggest that CXCL17 is involved in the proliferation of goat subcutaneous preadipocytes.

Objective: The aim of this study was to obtain goat CRTC2 gene sequence and elucidate its biological properties, and further study the impact of overexpression and interference of CRTC2 on the cell differentiation of goat subcutaneous precursor adipocytes.Methods: The sequence of goat CRTC2 was cloned by reverse transcription (RT)-polymerase chain reaction (PCR) and its molecular characterization was analyzed. The expression of CRTC2 gene in goat tissues and subcutaneous precursor adipocytes differentiated from 0 to 120 h was examined by quantitative real-time PCR (qRT-PCR). The effects of CRTC2 on the subcutaneous precursor adipocyte differentiation were investigated by using liposome transfection, Bodipy, Oil Red O staining and qPCR.Results: The results showed that the cloned goat CRTC2 gene was 2363 bp long (coding sequence [CDS] 2082 bp), encoding 693 amino acids. The relative expression levels of CRTC2 gene were highest in liver and then in kidney (p<0.05). During differentiation, the highest expression of CRTC2 in subcutaneous precursor adipocytes was observed at 120 of differentiating (p<0.01). In addition, we found that overexpression of CRTC2 significantly increased the expression of lipid metabolism-related genes (C/EBPα, C/EBPβ, PPARγ, DGAT1, DGAT2, ACC, FASN, SREBP1, AP2, LPL, ATGL) and promoted lipid accumulation. We then chemically synthesized goat CRTC2 small interfering RNA and transfected it into goat subcutaneous precursor adipocytes. The results revealed that SiRNA-mediated interference with CRTC2 significantly inhibited its differentiation and suppressed lipid droplet aggregation.Conclusion: So, this study indicates that CRTC2 is a positive regulator that promoting cell differentiation of subcutaneous adipocyte in goats, which lays the foundation for an in-depth study of the role of CRTC2 in lipid deposition in goats.

The differential fat deposition in intramuscular (IMF) and subcutaneous (SCF) adipose tissues significantly influences goat meat quality. While microRNAs (miRNAs) are key post-transcriptional regulators, the shared key miRNAs governing adipogenesis across different adipose depots remain largely unexplored in goats. In this study, intramuscular and subcutaneous preadipocytes were isolated from the same healthy 7-day-old male Jianzhou Da’er goat, and each experimental group comprised five independently cultured cell replicates derived from this donor. Integrated miRNA and mRNA sequencing was performed on undifferentiated intramuscular (JNE) and subcutaneous (PE) preadipocytes and their corresponding adipocytes after 72 h of differentiation (JNC and PC, respectively), allowing the identification of depot-specific and shared differentially expressed miRNAs (DEmiRNAs) and mRNAs (DEmRNAs). By constructing miRNA–mRNA regulatory networks, chi-miR-1 was identified as the highest-degree miRNA node in the shared network and was therefore prioritized for functional evaluation. RT-qPCR, chi-miR-1 mimic and inhibitor transfection, Oil Red O staining, and BODIPY staining showed that chi-miR-1 overexpression increased lipid droplet accumulation, whereas its inhibition produced the opposite effect in both intramuscular and subcutaneous adipocytes. Furthermore, bioinformatic target prediction and network analysis identified chi-miR-1–PPARG and chi-miR-206–IGFBP3 as predicted potential regulatory relationships; these interactions were not directly validated experimentally. Our findings, obtained using cells derived from a single donor, suggest that chi-miR-1 may serve as a candidate shared pro-adipogenic regulator under the present in vitro conditions and provide insights into miRNA-mediated regulation of adipogenesis in different goat adipose depots.