Résumé
A family of short interspersed repetitive elements (SINEs), designatedmermaid,is present in the genomes of fish, amphibian and primates, but absent in the mouse genome. We have demonstrated that the sequences of themermaidfamily are highly polymorphic in the zebrafish genome as in the human genome. We have also shown that themermaidsequence can be used to recover zebrafish specific DNA from zebrafish–mouse cell hybrids by usingmermaid-specific oligonucleotides as PCR primers. Thus, themermaidfamily serves as a valuable genetic tool for the zebrafish genome mapping.