Bernard C, Emerit I
J Natl Cancer Inst. 1982 Jun;68(6):951-8.
Two breeding lines of the NZB/BI mouse strain, which was originated from Bielschowsky's stock and maintained as a conventional inbred colony since 1963, were developed by selective matings according to chromosome breakage incidence in bone marrow cells. These breeding lines were used because they represent an interesting experimental model, since they differ in the manifestations of the autoimmune process and the incidence of lymphomas. The present study showed that embryos from both breeding lines differed in the expression of the xenotropic type C RNA virus, characteristic of NZB mice. All 17 cultures initiated with embryos from the line showing high chromosome breakage (HB) had positive reverse transcriptase (RT) reactions after cocultivation with an indicator cell line (SIRC). On the contrary, only 3 of the 22 embryos from the line showing low chromosome breakage (LB) had RT activity at late passages (7-10). The chromosome studies done on these embryo cultures showed highly significant differences in the chromosome breakage incidence for the 2 breeding lines [10.6 and 20.5% of cells with aberrations for LB and HB embryos, respectively (P less than 0.001)].
NZB/BI小鼠品系源自别尔绍夫斯基种群，自1963年起作为传统近交群体进行饲养。根据骨髓细胞中的染色体断裂发生率，通过选择性交配培育出了该品系的两个繁殖系。之所以使用这些繁殖系，是因为它们代表了一个有趣的实验模型，因为它们在自身免疫过程的表现和淋巴瘤的发生率方面存在差异。本研究表明，两个繁殖系的胚胎在异嗜性C型RNA病毒（NZB小鼠的特征性病毒）的表达上存在差异。用显示高染色体断裂率（HB）的繁殖系胚胎启动的所有17个培养物，在与指示细胞系（SIRC）共培养后，均出现了阳性逆转录酶（RT）反应。相反，显示低染色体断裂率（LB）的繁殖系的22个胚胎中，只有3个在传代后期（7 - 10代）具有RT活性。对这些胚胎培养物进行的染色体研究表明，两个繁殖系在染色体断裂发生率上存在极显著差异[LB和HB胚胎中出现染色体畸变的细胞分别占10.6%和20.5%（P < 0.001）]。
