Iraqi F, Smith E J
US Department of Agriculture, Avian Disease and Oncology Laboratory, Lansing, MI 48823, USA.
Anim Genet. 1995 Jun;26(3):141-6. doi: 10.1111/j.1365-2052.1995.tb03153.x.
Nucleotide sequence analysis of polymerase chain reaction products confirmed that ev21 integrated into one of two large homologous elements on the Z chromosome of late-feathering (LF) White Leghorn chickens. Southern blots of NotI-, NaeI-, KspI- and BamHI-digested DNA from early-feathering (EF) and LF White Leghorns, that had been hybridized with a probe that flanks ev21, indicated a 180 kb duplication of an unoccupied repeat in the LF genotype of White Leghorns. A KspI fragment that carries ev21 was about 32 kb smaller than the KspI fragment found in EF DNA. In the evolution of LF, retroviral insertion into one of two large repeats and a 32 kb deletion may have generated LF.
聚合酶链反应产物的核苷酸序列分析证实，ev21整合到晚羽（LF）白来航鸡Z染色体上两个大的同源元件之一中。用位于ev21侧翼的探针与早羽（EF）和LF白来航鸡经NotI、NaeI、KspI和BamHI消化的DNA进行Southern杂交，结果表明白来航鸡LF基因型中存在一个180 kb的未占用重复序列的重复。携带ev21的KspI片段比在EF DNA中发现的KspI片段小约32 kb。在LF的进化过程中，逆转录病毒插入两个大重复序列之一并发生32 kb的缺失可能产生了LF。
