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Author Greco, R. ♦ Ouwerkerk, P. B. F. ♦ Taal, A. J. C. ♦ Sallaud, C. ♦ Guiderdoni, E. ♦ Meijer, A. H. ♦ Hoge, J. H. C. ♦ Pereira, A.
Source SpringerLink
Content type Text
Publisher Springer-Verlag
File Format PDF
Copyright Year ©2004
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Life sciences; biology
Subject Keyword En/Spm ♦ Transcription ♦ Transposition ♦ Rice ♦ Arabidopsis
Abstract Transposition of the maize En/Spm system in rice was investigated using a two-component construct consisting of an immobilised transposase source driven by the CaMV 35S-promoter, and a modified I/dSpm transposon. Mobilization of I/dSpm in somatic sectors was demonstrated by sequencing of excision products and isolation of flanking genomic sequences in T0 and T1 progeny plants. Since the transposition efficiency appeared to be considerably lower than that observed in maize or in other heterologous systems like Arabidopsis, we examined En/Spm transcription and splicing in the transgenic rice plants. Northern analysis revealed the presence of transcripts encoding the active TnpA and TnpD transposases, with the latter predominating; this is the reverse of what is seen in maize and Arabidopsis. RT-PCR analysis confirmed the occurrence of correct splicing and the formation of the two other alternatively spliced transcripts (TnpB and TnpC), as previously described for maize. Two alternative splice donor sites at the end of exon 1 were identified in maize at positions 578 and 704. We observe that rice is similar to maize in that TnpA is preferentially spliced at position 578. We also show that in Arabidopsis splicing occurs preferentially at position 704, as in other dicots like tobacco. These observations indicate differences in the splicing of transcripts of the maize En/Spm element between dicot and monocot hosts. Nevertheless, the ratio in which the transcripts for the active transposases are produced seems to determine the efficiency of transposition, irrespective of the host considered. A limiting amount of TnpA might therefore be responsible for the lower transposition activity of En/Spm in rice. Alternatively, reduced mobility of the modified I/dSpm element used may have resulted from the absence of critical sequences necessary for transposition. The influence of endogenous, autonomous, En/Spm -related elements present in the rice genome on the transposition behaviour of the exogenous maize element is also considered.
ISSN 16174615
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2003-11-14
Publisher Place Berlin/Heidelberg
e-ISSN 16174623
Journal Molecular and General Genetics MGG
Volume Number 270
Issue Number 6
Page Count 10
Starting Page 514
Ending Page 523


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Source: SpringerLink