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ELOVL5 regulates bovine intramuscular fat deposition by balancing adipocyte proliferation and differentiation.

Yun Zhu , Haizhen Zhang

Abstract

Abstract: Context: Intramuscular fat (IMF) deposition is a key determinant of beef quality, influencing flavor, tenderness, and juiciness. Although the molecular drivers of adipogenesis are well-characterized in monogastric models, the regulatory networks specific to ruminants remain incompletely defined. Aim: In this study, we identify the fatty acid elongase ELOVL5 as a pivotal modulator of adipocyte development in cattle. Using primary bovine preadipocytes, we performed both loss-of-function (siRNA-mediated silencing) and gain-of-function (plasmid overex-pression) experiments to elucidate the role of ELOVL5. Methods: Primary bovine preadipocytes were isolated from Longissimus dorsi muscle of cattle and cultured under standard adipogenic conditions. Functional perturbations were performed via (1) siRNA-mediated ELOVL5 knockdown and (2) plasmid-driven ELOVL5 overexpression. Proliferation was assessed using CCK-8 assays (viability), EdU incorporation (DNA synthesis), and qPCR for cell cycle regulators (*CDK2/4/6*). Differentiation was evaluated through Oil Red O staining (lipid accumulation) and qPCR/Western blot analysis of adipogenic markers (*PPARγ, C/EBPα, FABP4*). Key results： ELOVL5 knockdown significantly enhanced preadipocyte proliferation, as demonstrated by increased expression of cell cycle regula-tors (CDK2, CDK4, CDK6), elevated cell viability (CCK-8 assay), and greater DNA synthesis (EdU incorporation). In contrast, overexpression of ELOVL5 suppressed these proliferative indices. However, ELOVL5 exhibited an inverse effect on adipogenic differentiation: knockdown attenu-ated lipid accumulation and downregulated key adipogenic transcription factors (PPARγ, C/EBPα, FABP4), whereas overexpression markedly promoted lipid deposition and expression of these genes. Conclusions：Taken together, these findings establish ELOVL5 as a bifunctional regulator that restrains preadipocyte proliferation while promoting terminal differentiation, positioning it as a critical molecular node in bovine adipogenesis. Implications：This dual role underscores the potential of ELOVL5 as a genetic target for modulating intramuscular fat content in cattle, with implications for enhancing beef quality through precision breeding and functional genomics.

AN25215  Accepted 10 October 2025

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