Leff J, Lam K B
J Bacteriol. 1976 Jul;127(1):354-61. doi: 10.1128/jb.127.1.354-361.1976.
Standard laboratory yeast strains can be enriched for thymidine 5'-monophosphate (TMP) uptake derivatives that generate only a low percentage of respiratory-deficient colonies (petites) under inhibition of TMP biosynthesis. Such mutants incorporated bromodeoxyuridine 5'-monophosphate (BrdUMP) into both nuclear and mitochondrial deoxyribonucleic acid (mtDNA); however, they showed a selectivity for TMP over BrdUMP incorporation. The preferential incorporation of [3H]TMP or BrdUMP into mtDNA was strain dependent. The density increments after growth in the presence of BrdUMP reached 50 mg/ml for nuclear DNA and 22 mg/ml for mtDNA in CsCl gradients. Density shifts corresponding to 4% bromouracil substitution were easily detected. Preliminary density transfer experiments confirm that mtDNA does not replicate in synchrony with nuclear DNA.
标准实验室酵母菌株可富集胸苷5'-单磷酸（TMP）摄取衍生物，这些衍生物在TMP生物合成受到抑制的情况下，产生呼吸缺陷型菌落（小菌落）的比例很低。此类突变体将溴脱氧尿苷5'-单磷酸（BrdUMP）掺入核脱氧核糖核酸（DNA）和线粒体脱氧核糖核酸（mtDNA）中；然而，它们对TMP的掺入表现出比对BrdUMP掺入的选择性。[3H]TMP或BrdUMP优先掺入mtDNA取决于菌株。在BrdUMP存在下生长后，CsCl梯度中核DNA的密度增量达到50mg/ml，mtDNA的密度增量达到22mg/ml。对应于4%溴尿嘧啶取代的密度变化很容易检测到。初步的密度转移实验证实，mtDNA与核DNA不同步复制。
