The Sequence Characterization of the Somatic Footprints upon the Transposition of Non-autonomous Transposon rDt in Maize
Dotted/rDt is one of the earliest two-element transposon systems discovered in maize genetic research.The a1-rDt;Dt and the a1-m1::rDt;Dt are two A1 mutations with distinguishable kernel spotting phenotype,few uniform spots vs many varied-size spots.To explore the genetic characteristics of the somatic and germinal transposition of the same non-autonomous transposon rDt in either mutant line under the regulation of autonomous transposon Dt,nest-PCR amplification and restriction endonuclease digestion were applied to reveal the genetic bases for the variation in the size and number of somatic reversion spots in the aleu-rone by sequence analysis on the footprints at the different insertion sites of two alleles.Furthermore,segregation populations were constructed for A1'reversion frequency.The results showed that only two types of somatic footprint sequence were detected in a1-rDt;Dt line,including the exact wild-type sequence prior to any insertions.In contrast,five types of somatic footprint sequence were detected in a1-m1::rDt;Dt line with densely populated aleurone full of various purple spots,and three of them remained in the right open reading frame of possible A1'reversion genes.Meanwhile,the reversion frequency to A1'in a1-m1::rDt;Dt lines was 2.6 times higher than that in a1-rDt;Dt lines.These relatively simple composition of excision footprint upon somatic transposi-tions of rDt at a1 locus was comparable with that of other family members from the hAT transposon superfamily such as Ac/Ds.Thus,the higher reversion frequency together with multiple reversion alleles may genetically contribute to the perceptible differences from spotting phenotype pattern in aleurone of the tow tested a1-rDt alleles.
万方数据
维普
