China Animal Husbandry & Veterinary Medicine ›› 2026, Vol. 53 ›› Issue (1): 317-332.doi: 10.16431/j.cnki.1671-7236.2026.01.029

• Genetics and Breeding • Previous Articles     Next Articles

Construction and Functional Study of FGFR1 Gene Knockout Bovine Mammary Epithelial Cell Line

GAO Linna1,2(), JIANG Yingying1,3, HUANG Guangjun1,3, WANG Yue1,3, SHI Qianqian1,2, WANG Huili1, CHEN Kunlin1()   

  1. 1.Key Laboratory of Crop and Animal Integrated Farming,Ministry of Agriculture and Rural Affairs,Jiangsu Province Engineering Research Center for Precision Animal Breeding,Institute of Animal Science,Jiangsu Academy of Agricultural Sciences,Nanjing 210014,China
    2.School of Life Sciences and Food Engineering,Hebei University of Engineering,Handan 056038,China
    3.College of Animal Science and Technology,Nanjing Agricultural University,Nanjing 210095,China
  • Received:2025-05-12 Online:2026-01-05 Published:2025-12-26
  • Contact: CHEN Kunlin E-mail:13292751837@163.com;chenkunlin@jaas.ac.cn

Abstract:

Objective This study aimed to establish a fibroblast growth factor receptor 1 (FGFR1) gene knockout bovine mammary epithelial cell line (bMECs) using CRISPR/Cas9 technology, and investigate the effects of FGFR1 gene deletion on cell viability, proliferation, and lactation function, thereby elucidating its molecular regulatory mechanisms in mammary gland development and lactation. Method sgRNAs were designed targeting exons 3 and 4 of FGFR1 gene. Following in vitro assessment of cleavage efficiency, a knockout plasmid for FGFR1 gene was generated. Genomic DNA was collected 7 d post-screening, and PCR amplification along with Sanger sequencing were employed to confirm FGFR1 gene editing. Monoclonal cells were isolated from the edited cell population using the limiting dilution method. FGFR1 gene knockout cell lines with a singular genotype were subsequently identified through TA cloning. The knockout efficiency of monoclonal cell lines was assessed via Western blotting, while cell viability was determined using CCK-8 assay. Additionally, Real-time quantitative PCR was utilized to evaluate the expression of genes associated with proliferation and lactation in the monoclonal cell lines. Result The in vitro cleavage assay demonstrated cleavage efficiencies of 82.87% and 27.80% for the two sgRNAs, confirming successful construction of the knockout plasmid. Subsequently, over 95% of bMECs displayed red fluorescence 72 h post-electrotransfection, with multiple double peaks observed in the target region following drug screening, indicating a pronounced editing effect. From a pool of 384 monoclonal cell lines, 92 were successfully propagated, with 72 (78.26%) exhibiting FGFR1 gene editing, 31 (33.70%) showing sgRNA1 site editing, and 55 (59.78%) displaying sgRNA2 site editing. Ultimately, 8 robust monoclonal cell lines were isolated. Sequencing analysis revealed diverse editing patterns among the monoclonal cell lines, including fragment deletions and base substitutions. Notably, the KO#2 cell line exhibited editing at two sites with a single editing type. Western blotting and CCK-8 results showed that compared with control group, the knockout effect of KO#2 strain cells was extremely significant (P<0.01), while FGFR1 gene knockout did not significantly impact cell viability (P>0.05). Real-time quantitative PCR analysis results revealed that compared with control group, there was no significant differences in the expression of genes associated with cell proliferation (P>0.05). However, the significant reduction in the expression of genes related to lactation function was observed(P<0.05 or P<0.01). Conclusion This study successfully constructed one strain of bMECs with FGFR1 gene knockout, indicate that the absence of FGFR1 gene did not notably impact cell survival and proliferation, but significantly inhibited lactation synthesis function. The results provided a basis for future investigations into the role and mechanisms of FGFR1 gene in bMECs.

Key words: FGFR1 gene; bovine mammary epithelial cell line (bMECs); CRISPR/Cas9; gene editing; lactation regulation

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