Tdr2, a new zebrafish transposon of the Tc1 family

We describe here Tdr2, a new class of Tc1-like transposons in zebrafish. Td r2 was identified from the genomic sequence of a zebrafish PAC (P1 artifici al chromosome) clone, and fragments of Tdr2 were found in several zebrafish EST (expressed sequence tag) sequences. Predicted translation of the Tdr2 transposase gene showed that it was most closely related to Caenorhabditis elegans Tc3A, suggesting an ancient origin of the Tdr2 transposon. Tdr2 spa ns 1.1 kb and is flanked by inverted repeats of approx. 100 bp. The 5' repe at is itself composed of an inverted repeat, raising the possibility of the formation of a cruciform DNA structure. Tdr2 transposons may facilitate th e development of novel transposon-based tools for the genetic analysis of z ebrafish. (C) 1999 Elsevier Science B.V. All rights reserved.