R. Weide et al., PARACENTROMERIC SEQUENCES ON TOMATO CHROMOSOME-6 SHOW HOMOLOGY TO HUMAN SATELLITE-III AND TO THE MAMMALIAN CENP-B BINDING BOX, MGG. Molecular & general genetics, 259(2), 1998, pp. 190-197
In order to isolate centromeric sequences from tomato (Lycopersicon es
culentum) chromosome 6, a large-scale RAPD screen was performed. Among
1500 polymorphic RAPD markers tested, 100 were identified as chromoso
me 6-specific, using a L. esculentum substitution line carrying chromo
some 6 from L. pennellii. Fifty-seven of these markers proved to origi
nate from L. pennellii, and of these, 13 were genetically mapped betwe
en the morphological markers yellow virescent (yv) and thiaminless (tl
), which flank the centromere. These markers could be assigned to thre
e genetic loci, with 11 of the markers mapping to a single locus. Furt
her resolution of this cluster was achieved using radiation-induced de
letions that removed vv or tl but not the centromere. Seven markers we
re shown to be located outside all of the deletions. These seven marke
rs and three of the other markers of the cluster were cloned and seque
nced. Five of the clones are present as single-copy or low-copy-number
sequences and five represent middle repetitive sequences. Three seque
nces show homology to the mammalian CENP-B binding box clone AG12 cont
ains two of these boxes and also shows homology to human satellite III
.