The transposable element Tam1 from Antirrhinum majus shows structural homology to the maize transposon En/Spm and has no sequence specificity of insertion.
We present the genomic structure of Tam1, a transposable element from Antirrhinum majus. The Tam1 element is 15.2 kb long and includes two genes that are transcribed to produce a 2.4 kb (tnp1) and a 5 kb mRNA (tnp2). These transcripts partially overlap and the exons are scattered over the whole element. Tnp1 encodes a 53 kDa protein as deduced from the cDNA sequence. The 5 kb transcript of tnp2 contains an open reading frame that shares 45% homology with part of the tnpD gene of En/Spm from maize and 48% homology with an open reading frame of the Tgm element from Glycine max. We discuss the possible functions of these genes by analogy with En/Spm. Additionally, a number of flanking sequences of Tam1 insertions were analysed to investigate the sequence specificity of insertion. From these studies we conclude that Tam1 transposes predominantly into AT-rich regions that can be unique as well as repetitive. No specific target sequence of insertion could be found.
Nacken
W K
WK
Max-Planck-Institut für Züchtigungsforschung, Köln, FRG.
Piotrowiak
R
R
Saedler
H
H
Sommer
H
H
D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004247:DNA / Q000302:isolation & purification; D004251:DNA Transposable Elements / Q000235:genetics*; D008969:Molecular Sequence Data; D010944:Plants / Q000235:genetics*; D011061:Poly A / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D012313:RNA / Q000302:isolation & purification; D012333:RNA, Messenger; D012689:Sequence Homology, Nucleic Acid; D003313:Zea mays / Q000235:genetics*
D004251:DNA Transposable Elements; D012333:RNA, Messenger; D011061:Poly A; D012313:RNA; D004247:DNA