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Triticeae Genomics and Genetics 2012, Vol.3, No.3, 25
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brachypodium chromosomes had homoeologs of
wheat genes (ESTs) from one or more consensus
chromosomes and vice-versa. These common features
indicated that both the genomes evolved from a
common ancestor. Regions of similarity between
wheat and brachypodium genomes, studied through
chromosome to chromosome matching are shown in
figure 1.
1.2 Syntenic relationship of individual wheat conse-
nsus chromosomes with brachypodium chromosomes
1.2.1 Wheat consensus chromosome 1 (WC1)
As given in Table 1, the WC1 map carries 169 matching
wESTs, of which 61.5% were syntenic with Bd2
(WC3 is also largely syntenous with Bd2), 27.2%
were syntenic with Bd3 and the remaining 11.3%
wESTs were syntenic to the remaining three brachy-
podium chromosomes (Bd1, Bd4 and Bd5). The short
arm of WC1 (WC1S) largely matched Bd2 except a
bin between 0.48
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0.50 FL (fraction length of arm)
was syntenic with Bd3. The proximal region (50%) of
the long arm of WC1 (WC1L) matched mainly with
Bd3 and distal region (rest 50%) matched with Bd2,
while the interstitial region 0.41
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0.61 FL in WC1L
was a composite of Bd3 and Bd2. In summary, the
relationship between WC1 and brachypodium chro-
mosomes may be summarized as follows: WC1S-C-
WC1L = Bd2/Bd3/Bd2
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C-Bd3/Bd2, where “C” refers
to the relative position of centromere on the wheat
chromosome (Figure 1). The centromere synteny
between WC1, rice chromosome 5 and Bd2 is known
(Qi et al., 2010). Utilizing this information wEST
BE499250 in pericentromeric region of WC1S seems
Figure 1 Syntenic relationships between wheat and brachypodium chromosomes
Note: The seven consensus chromosomes of wheat are shown in pink colour; The deletion break point and fraction length value are
shown on left of each chromosome; The boxes are colour coded according to the syntenic relationship with brachypodium
chromosomes; The number of wESTs showing significant matches with brachypodium sequences is shown inside the coloured boxes,
while the number of wESTs showing significant matches with more than one brachypodium chromosomes is shown outside the
coloured boxes; ‘C’ represents position of centromere
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