Fanning T G
Laboratory of Biochemistry, National Cancer Institute, Bethesda, MD 20892.
J Mol Biol. 1987 Oct 20;197(4):627-34. doi: 10.1016/0022-2836(87)90469-4.
A major satellite DNA has been cloned from the domestic cat (Felis catus) and characterized. The satellite monomer, termed FA-SAT, is 483 base-pairs in size, 64% G + C, and represents about 1 to 2% of the cat genome. A consensus sequence based upon partial sequence data from 21 independently isolated clones demonstrates: (1) FA-SAT is not composed of a series of shorter repeats, although about 25 copies, primarily imperfect, of the hexanucleotide TAACCC appear in the sequence; (2) there are many more CpG dinucleotides present in FA-SAT than expected for a random sequence of its size; and (3) 61% of all base substitutions in FA-SAT involve the replacement of G and C residues by A and T residues, indicating that FA-SAT is rapidly becoming A + T-rich. FA-SAT-related sequences are found in many mammals, where they appear to be scattered throughout the genome and not tandemly arranged as in the cat. An FA-SAT-related sequence was cloned from the domestic dog genome and sequenced, and shown to contain multiple copies of the same TAACCC hexanucleotide found in the cat satellite.
已从家猫（Felis catus）中克隆并鉴定出一种主要的卫星DNA。这种卫星单体被称为FA-SAT，大小为483个碱基对，G + C含量为64%，约占猫基因组的1%至2%。基于21个独立分离克隆的部分序列数据得出的共有序列表明：（1）FA-SAT并非由一系列较短的重复序列组成，尽管序列中出现了约25个拷贝的六核苷酸TAACCC，且主要是不完美的拷贝；（2）FA-SAT中存在的CpG二核苷酸比其大小的随机序列预期的要多得多；（3）FA-SAT中所有碱基替换的61%涉及G和C残基被A和T残基取代，这表明FA-SAT正迅速变得富含A + T。在许多哺乳动物中都发现了与FA-SAT相关的序列，它们似乎分散在整个基因组中，不像在猫中那样串联排列。从家犬基因组中克隆并测序了一个与FA-SAT相关的序列，结果显示它含有与猫卫星中相同的TAACCC六核苷酸的多个拷贝。
