TY  - JOUR
A1  - Bruggmann, Rémy
A1  - Bharti, Arvind K.
A1  - Gundlach, Heidrun
A1  - Lai, Jinsheng
A1  - Young, Sarah
A1  - Pontaroli, Ana C.
A1  - Wei, Fusheng
A1  - Haberer, Georg
A1  - Fuks, Galina
A1  - Du, Chunguang
A1  - Raymond, Christina
A1  - Estep, Matt C.
A1  - Liu, Renyi
A1  - Bennetzen, Jeffrey L.
A1  - Chan, Agnes P.
A1  - Rabinowicz, Pablo D.
A1  - Quackenbush, John
A1  - Barbazuk, W. Brad
A1  - Wing, Rod A.
A1  - Birren, Bruce
A1  - Nusbaum, Chad
A1  - Rounsley, Steve
A1  - Mayer, Klaus F.X.
A1  - Messing, Joachim
T1  - Uneven chromosome contraction and expansion in the maize genome
Y1  - 2006/10/01 
JF  - Genome Research 
JO  - Genome Research 
SP  - 1241 
EP  - 1251 
DO  - 10.1101/gr.5338906 
VL  - 16 
IS  - 10 
UR  - http://genome.cshlp.org/content/16/10/1241.abstract 
N2  - Maize (Zea mays or corn), both a major food source and an important cytogenetic model, evolved from a tetraploid that arose about 4.8 million years ago (Mya). As a result, maize has extensive duplicated regions within its genome. We have sequenced the two copies of one such region, generating 7.8 Mb of sequence spanning 17.4 cM of the short arm of chromosome 1 and 6.6 Mb (25.6 cM) from the long arm of chromosome 9. Rice, which did not undergo a similar whole genome duplication event, has only one orthologous region (4.9 Mb) on the short arm of chromosome 3, and can be used as reference for the maize homoeologous regions. Alignment of the three regions allowed identification of syntenic blocks, and indicated that the maize regions have undergone differential contraction in genic and intergenic regions and expansion by the insertion of retrotransposable elements. Approximately 9% of the predicted genes in each duplicated region are completely missing in the rice genome, and almost 20% have moved to other genomic locations. Predicted genes within these regions tend to be larger in maize than in rice, primarily because of the presence of predicted genes in maize with larger introns. Interestingly, the general gene methylation patterns in the maize homoeologous regions do not appear to have changed with contraction or expansion of their chromosomes. In addition, no differences in methylation of single genes and tandemly repeated gene copies have been detected. These results, therefore, provide new insights into the diploidization of polyploid species. 
ER  -