Yonekawa H, Katoh H, Esaki K, Sagai T, Moriwaki K, Tagashira Y
Lab Anim Sci. 1986 Dec;36(6):659-64.
Six sublines of NZB mice bred in Japan were collected and their mitochondrial DNA (mtDNA) was examined by restriction analysis. The phenotypes of at least three of these sublines (NZB/Nrs, NZB/Nga and NZB/KlJms) differed from a standard one (NZB/BlWehi). Since mtDNA is inherited maternally, all sublines of a single inbred strain should share the same mtDNA phenotype. Therefore, b-type of mtDNA should be observed in all NZB sublines. Nevertheless, the above-mentioned sublines showed d-type mtDNA. These results suggested a genetic contamination of these sublines. This was confirmed by the finding that six aberrant alleles were detected also in their nuclear genomes using biochemical markers. For elucidation of the cause of contamination, we characterized the genetic profiles of four standard NZ-strains, NZB/BlWehi NZO/BlWehi, NZC/BlWehi and NZX/BlWehi, and of common inbred strains with black coat color, C57BL/6J, C57BL/10Sn, C57BL/Ks, C58/J and AU/SsJ. We found that five of the six aberrant alleles most strongly corresponded with those of C57BL/Ks. These results suggest that this contamination was ascribable to cross of NZB mice with a certain C56BL strain. We also deduced that NAB/BlPt and NZB/Füll also probably were contaminated strains, suggesting that this contamination was not restricted to Japan.
收集了在日本培育的6个NZB小鼠亚系，并通过限制性分析检测了它们的线粒体DNA（mtDNA）。其中至少3个亚系（NZB/Nrs、NZB/Nga和NZB/KlJms）的表型与标准亚系（NZB/BlWehi）不同。由于mtDNA是母系遗传的，单一近交系的所有亚系应该具有相同的mtDNA表型。因此，在所有NZB亚系中都应该观察到b型mtDNA。然而，上述亚系显示为d型mtDNA。这些结果提示这些亚系存在基因污染。利用生化标记在它们的核基因组中也检测到6个异常等位基因，这证实了基因污染的存在。为了阐明污染的原因，我们对4个标准NZ品系NZB/BlWehi、NZO/BlWehi、NZC/BlWehi和NZX/BlWehi以及具有黑色被毛的常见近交系C57BL/6J、C57BL/10Sn、C57BL/Ks、C58/J和AU/SsJ的遗传图谱进行了特征分析。我们发现6个异常等位基因中的5个与C57BL/Ks的等位基因对应性最强。这些结果表明这种污染是由于NZB小鼠与某个C56BL品系杂交所致。我们还推断NAB/BlPt和NZB/Füll可能也是污染品系，这表明这种污染并不局限于日本。
