Carola Valeria, D'Olimpio Francesca, Brunamonti Emiliano, Bevilacqua Arturo, Renzi Paolo, Mangia Franco
Department of Psychology, Section of Neuroscience, University of Rome "La Sapienza", Via dei Marsi 78, I-00185 Rome, Italy.
Behav Brain Res. 2004 Apr 2;150(1-2):25-32. doi: 10.1016/S0166-4328(03)00217-1.
In a previous study on anxiety-related behaviours of the genetically and behaviourally distant inbred mouse strains C57BL/6 and BALB/c using the Elevated plus-maze (EPM) and Open-field (OF) apparatuses, we identified a number of variables, the factorial scores of which were grouped by principal component analysis (PCA) into factors specifically describing each inbred strain. We have now studied the effect of C57BL/6 and BALB/c haploid sets of genes on this behaviour by comparing EPM and OF variables of C57BL/6 and BALB/c versus C57BL/6 x BALB/c F1 hybrids (B6CBF1) and chimeric C57BL/6 x BALB/c (CHIM) mice. CHIM mice were made by embryo aggregation and the chimerism degree of their brain was inferred from coat black/white distribution. Discriminant analysis of EPM and OF factorial scores of C57BL/6, BALB/c and CHIM mice showed that CHIM mice with an exceeding (> or =80%) C57BL/6 or BALB/c coat component had behaviours similar to those of the predominant strain, whereas CHIM mice with intermediate chimerism differed from both inbred strains. Additional MANOVA analysis showed that the anxiety behaviour of CHIM mice with intermediate chimerism was similar to that of B6CBF1 mice as for factors not describing the inbred strains, including a motor activity mostly limited to protected areas, with attempts to approach the anxiogenic areas while processing/storing the external information. We conclude that the balanced presence of both C57BL/6 and BALB/c genetic backgrounds, either when carried by the same cell or by different cells, gives rise to a novel stress coping strategy described by factors different from those of the inbred strains.
在之前一项关于基因和行为差异较大的近交系小鼠品系C57BL/6和BALB/c焦虑相关行为的研究中，我们使用高架十字迷宫（EPM）和旷场（OF）装置确定了一些变量，通过主成分分析（PCA）将这些变量的因子得分分组为专门描述每个近交系的因子。我们现在通过比较C57BL/6和BALB/c与C57BL/6×BALB/c F1杂种（B6CBF1）和嵌合C57BL/6×BALB/c（CHIM）小鼠的EPM和OF变量，研究了C57BL/6和BALB/c单倍体基因组对这种行为的影响。CHIM小鼠通过胚胎聚集制备，其大脑的嵌合程度从皮毛黑白分布推断。对C57BL/6、BALB/c和CHIM小鼠的EPM和OF因子得分进行判别分析表明，C57BL/6或BALB/c皮毛成分超过（≥80%）的CHIM小鼠具有与优势品系相似的行为，而嵌合程度中等的CHIM小鼠与两个近交系均不同。额外的多变量方差分析表明，嵌合程度中等的CHIM小鼠的焦虑行为在不描述近交系的因子方面与B6CBF1小鼠相似，包括运动活动大多局限于保护区，在处理/存储外部信息时试图接近焦虑源区域。我们得出结论，C57BL/6和BALB/c遗传背景的平衡存在，无论是由同一细胞携带还是由不同细胞携带，都会产生一种由不同于近交系的因子描述的新型应激应对策略。
