ISSN:
1432-2145
Keywords:
Key words Maize
;
Retrotransposon
;
Microspore expression
;
Polygalacturonase genes
;
Genome structure
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract We have isolated, by screening a genomic library, a retroelement from maize designated PREM-2 (pollen retroelement maize-2), which is expressed in a tissue-specific manner. RNA transcripts of the PREM-2 family are found in the microspore but not in more mature pollen or in any of the vegetative tissues examined. The expression of PREM-2 elements in the uninucleate microspore provides an explanation for the genetic transmission of genomic rearrangements caused by the transposition of retroelements. PREM-2 elements are very abundant and are estimated to constitute about 5% of the maize genome and could possibly have played an important role in the determination of genome structure and in the generation of repetitive sequences in maize. The entire PREM-2 element is 9439 bp long. The LTRs of PREM-2 are 1307 bp in length. The internal region between the 5′ and 3′ LTRs contains 6825 bp and shares homology to the gag, pro, int, RT, and RNaseH regions of copia-type retroelements. PREM-2 elements have been found in close proximity with several maize genes registered in GenBank. The presence of PREM-2 sequence in the exact 5′ flanking position of three polygalacturonase genes expressed in pollen, has been used to examine the evolution of the polygalacturonase multigene family in maize and to estimate the time of the PREM-2 integration event.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004970050012
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