Two families of repetitive DNA sequences were isolated from the zebrafish genome and characterized. Eight different sequences were sequenced and classified by two standards, their (G + C) composition and their lengths. For convenience, the sequences were first divided into two types. Type I was (A + T)-rich, was repeated approximately 500,000 times, and constituted approximately 5% of the zebrafish genome. Type II was (G + C)-rich, was reiterated approximately 90,000 times, and comprised approximately 0.5% of the genome. Agarose gel electrophoresis of zebrafish DNA cleaved with AluI revealed three distinguishable bands of repetitive fragments: large (approximately 180 bp, designated RFAL), medium (approximately 140 bp, RFAM), and small (approximately 90 bp, RFAS). The RFAL fragments contained both type I and type II sequences. Limited digestion of genomic DNA indicated that RFAL and RFAM were tandemly arranged in the genome, whereas RFAS showed a mixed pattern of both tandem and interspersed repeated arrangements. Although inclusion of a repetitive sequence in a transgenic construct did not appreciably accelerate homologous integration of transgenes into the zebrafish genome, the AluI sequences could facilitate transgene mapping following chromosomal integration.
|Original language||English (US)|
|Number of pages||11|
|Journal||Molecular marine biology and biotechnology|
|State||Published - Apr 1992|