Porter C A
Department of Biological Sciences, Texas Tech University, Lubbock 79409.
Chromosome Res. 1994 Jul;2(4):263-73. doi: 10.1007/BF01552720.
Repetitive DNA sequences were isolated from the genomes of species representing three major clades of squamate reptiles. A repetitive sequence (Cn4C7) was isolated from the New Mexican whiptail lizard, Cnemidophorus neomexicanus. This sequence is distributed throughout the chromosomes, but is more concentrated in the telomeric region. Cn4C7 also hybridizes to the chromosomes of other Cnemidophorus. Some evidence was found for concerted evolution of this repeat in hybrid unisexual lineages. In the lesser earless lizard, Holbrookia maculata, the predominant repeat in the genome is represented by a sequence (Hm1E11) which is restricted to the area flanking the centromere in all species of Holbrookia. Two families of repetitive sequences (one dispersed, and the other telomeric) were isolated from the western diamondback rattlesnake, Crotalus atrox. The type and distribution of repetitive sequences in squamates is often taxon-specific, and may be useful as characters for elucidating taxonomic relationships.
重复DNA序列是从代表有鳞目爬行动物三个主要进化枝的物种基因组中分离出来的。从新墨西哥鞭尾蜥（Cnemidophorus neomexicanus）的基因组中分离出一个重复序列（Cn4C7）。该序列分布于整个染色体，但在端粒区域更为集中。Cn4C7也能与其他鞭尾蜥属物种的染色体杂交。在杂交单性谱系中发现了该重复序列协同进化的一些证据。在小耳蜥（Holbrookia maculata）中，基因组中的主要重复序列由一个序列（Hm1E11）代表，该序列在所有小耳蜥属物种中都局限于着丝粒两侧区域。从西部菱斑响尾蛇（Crotalus atrox）中分离出两个重复序列家族（一个是分散的，另一个是端粒的）。有鳞目动物中重复序列的类型和分布通常具有分类群特异性，可能有助于作为阐明分类关系的特征。
