Profiling expression changes caused by a segmental aneuploid in maize.
BACKGROUND
While changes in chromosome number that result in aneuploidy are associated with phenotypic consequences such as Down syndrome and cancer, the molecular causes of specific phenotypes and genome-wide expression changes that occur in aneuploids are still being elucidated.


RESULTS
We employed a segmental aneuploid condition in maize to study phenotypic and gene expression changes associated with aneuploidy. Maize plants that are trisomic for 90% of the short arm of chromosome 5 and monosomic for a small distal portion of the short arm of chromosome 6 exhibited a phenotypic syndrome that includes reduced stature, tassel morphology changes and the presence of knots on the leaves. The knotted-like homeobox gene knox10, which is located on the short arm of chromosome 5, was shown to be ectopically expressed in developing leaves of the aneuploid plants. Expression profiling revealed that approximately 40% of the expressed genes in the trisomic region exhibited the expected 1.5 fold increased transcript levels while the remaining 60% of genes did not show altered expression even with increased gene dosage.


CONCLUSIONS
We found that the majority of genes with altered expression levels were located within the chromosomal regions affected by the segmental aneuploidy and exhibits dosage-dependent expression changes. A small number of genes exhibit higher levels of expression change not predicted by the dosage, or display altered expression even though they are not located in the aneuploid regions.
Makarevitch
Irina
I
Microbial and Plant Genomics Institute, Department of Plant Biology, University of Minnesota, St, Paul MN 55108, USA. springer@umn.edu.
Phillips
Ronald L
RL
Springer
Nathan M
NM
D000782:Aneuploidy; D018628:Gene Dosage; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D005801:Genes, Homeobox; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D003313:Zea mays / Q000235:genetics*
D010940:Plant Proteins