期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1991
卷号：88
期号：13
页码：5814-5818
DOI：10.1073/pnas.88.13.5814
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：CR1 is a short interspersed repetitive DNA element originally identified in the domestic chicken (Gallus gallus). However, unlike virtually all other such sequences described to date, CR1 is not confined to one or a few closely related species. It is probably a ubiquitous component of the avian genome, having been detected in representatives of nine orders encompassing a wide spectrum of the class Aves. This identification was made possible by using the polymerase chain reaction (PCR), which revealed interspecific similarities not detected by conventional Southern analysis. DNA sequence comparisons between a CR1 element isolated from a sarus crane (Grus antigone) and those isolated from an emu (Dromaius novaehollandiae) showed that two short highly conserved regions are present. These are included within two regions previously characterized in the CR1 units of domestic fowl. One of these behaves as a transcriptional silencer and the other is a binding site for a nuclear protein. Our observations suggest that CR1 has evolved under functional constraints and that interspersed repetitive sequences as a class may constitute a more significant component of the eukaryotic genome than is generally acknowledged.
