Mouse models are widely used in the study of musculoskeletal radiobiology both in vivo and in vitro. Two of the most commonly used mouse strains are C57BL/6 and BALB/c. However, little is known about their equivalence in response to ionizing radiation. In this study we compare the responses of marrow stromal cells derived from both of these strains to X rays in vitro at passages 0 and 2. Colony-forming efficiency was significantly higher in BALB/c marrow stromal cells at passage 0. Radiation-induced decreases in colony-forming unit (CFU) formation at passage 0 were comparable across both strains at 0–2 Gy, but BALB/c stromal cells were more radiosensitive than C57BL/6 stromal cells at 3–7 Gy. Osteogenic differentiation at passage 2 was not affected by radiation for either strain. This work demonstrates that commonly used inbred mouse strains differ in their early-passage marrow stromal cell responses to X rays, including self-renewal and differentiation potential. This variability is an important point to consider when selecting an animal model for in vivo or in vitro study.

小鼠模型广泛用于体内和体外的肌肉骨骼放射生物学研究。两种最常用的小鼠品系是 C57BL/6 和 BALB/c。然而，关于它们对电离辐射的等效性知之甚少。在这项研究中，我们比较了来自这两种菌株的骨髓基质细胞对体外 X 射线的反应在第 0 代和第 2 代。在第 0 代时，BALB/c 骨髓基质细胞的集落形成效率显着更高。在第 0 代，辐射诱导的集落形成单位 (CFU) 形成的减少在 0-2 Gy 的两种菌株中相当，但 BALB/c 基质细胞在 3-7 Gy 时比 C57BL/6 基质细胞对放射线更敏感。第 2 代的成骨分化不受任何菌株辐射的影响。这项工作表明，常用的近交小鼠品系在其早期传代骨髓基质细胞对 X 射线的反应方面存在差异，包括自我更新和分化潜能。在为体内或体外研究选择动物模型时，这种可变性是需要考虑的重要一点。