作者: Helal A. Ansari , Nick W. Ellison , Andrew G. Griffiths , Warren M. Williams
DOI: 10.1023/B:CHRO.0000034099.19570.B7
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摘要: We report the molecular structure, genomic organization, chromosomal distribution and evolutionary dynamics of TrR350, a satellite DNA isolated from forage legume white clover (Trifolium repens L.; 2n = 4x= 32). The basic repeating unit is an A+T rich 350 bp HindIII fragment with complex dimeric structure consisting internal direct repeat 156 packed between unrelated flanking sequences. Each has conserved 24 motif at two places. Most short units enclose pentanucleotide CAAAA motif, presumed to be involved in breakage-reunion mechanism tandemly arrays. dimers share high sequence homology among themselves while monomers within show significant divergence. Genomic Southern hybridization and/or fluorescence situ (FISH) on 17 Trifolium species/subspecies revealed that it lineage-specific confined several species section Lotoidea originating Mediterranean region. uniform length centromeric localization most harbouring reflects its extensive conservation lineage. However, restriction profile seven also indicated independent evolution this repeat.