卡尔斯伯酵母中的染色体外环状核糖体DNA。

Meyerink J H, Klootwijk J, Planta R J, van der Ende A, van Bruggen E F

Nucleic Acids Res. 1979 Sep 11;7(1):69-76. doi: 10.1093/nar/7.1.69.

Purified ribosomal DNA from Saccharomyces carlsbergensis contains a small proportion of circular DNA molecules with a contour length of 3 micron or integral multiples thereof. Hybridization of yeast ribosomal DNA with 26 S rRNA, using the R-loop technique, reveals that these circular molecules contain sequences complementary to yeast ribosomal RNA. We suggest that these extrachromosomal rRNA genes may be intermediates in the amplification of rRNA genes in yeast.

从卡尔斯伯酵母中纯化得到的核糖体DNA含有一小部分环形DNA分子，其轮廓长度为3微米或其整数倍。利用R环技术使酵母核糖体DNA与26S rRNA杂交，结果表明这些环形分子含有与酵母核糖体RNA互补的序列。我们认为这些染色体外的rRNA基因可能是酵母中rRNA基因扩增的中间体。