Schmitz-Linneweber C, Maier R M, Alcaraz J P, Cottet A, Herrmann R G, Mache R
Botanisches Institut der Ludwig-Maximilians-Universität, München, Germany.
Plant Mol Biol. 2001 Feb;45(3):307-15. doi: 10.1023/a:1006478403810.
The chloroplast chromosome of spinach (Spinacia oleracea) is a double-stranded circular DNA molecule of 150,725 nucleotide pairs. A comparison of this chromosome with those of the three other autotrophic dicotyledons for which complete DNA sequences of plastid chromosomes are available confirms a conserved overall structure. Three classes of open reading frames were distinguished: (1) genes of known function which include 108 unique loci, (2) three hypothetical chloroplast reading frames (ycfs) that are highly conserved interspecifically, and (3) species-specific or rapidly diverging 'open reading frames'. A detailed transcript study of one of the latter (ycf15) shows that these loci may be transcribed, but do not constitute protein-coding genes.
菠菜（Spinacia oleracea）的叶绿体染色体是一个由150,725个核苷酸对组成的双链环状DNA分子。将该染色体与另外三种质体染色体DNA序列已完整测定的自养双子叶植物的染色体进行比较，证实了整体结构的保守性。区分出了三类开放阅读框：（1）已知功能的基因，包括108个独特位点；（2）三个种间高度保守的假定叶绿体阅读框（ycfs）；（3）物种特异性或快速分化的“开放阅读框”。对后者之一（ycf15）的详细转录本研究表明，这些位点可能被转录，但并不构成蛋白质编码基因。
