Two transposable elements have been identified at the dunce locus in chromosomes recovered after a premeiotic and interchromosomal conversion event occurred at this gene. One is approximately 8.2 kb and is inserted near the 5' end of the gene. This element was identified by sequence analysis as a member of the B104 (roo) family of copia-like transposable elements. The second resides near the 3' end of the gene and represents a new family of the class of poly-deoxyadenylated [poly(dA)] transposable elements. It is 0.38 kb in length and has one terminus consisting of a stretch of 29 deoxyadenosine residues with a polyadenylation site like those found in mRNA molecules, located about 20 bp away from the poly(dA) stretch. Fourteen base pairs of genome DNA is duplicated at the target site of this element.