While rapidly accumulating life information such as genome sequences and gene expressions due to technological innovation, how to find the biological significance from the vast amounts of information is increasingly important in the future. We conduct evolutionary analyses of genes and genomes for understanding genetic background of interesting phenotypes by using such large-scale life information. In particular, we work on the influence of duplicated genes on phenotypes such as disease and ecological characteristics.
One increasingly popular hypothesis is that dosage balance constraints are a major determinant of duplicate gene retention. We test this hypothesis and show that WGD-duplicated genes (ohnologs) have rarely experienced subsequent small-scale duplication (SSD) and are also refractory to copy number variation (CNV) in human populations and are thus likely to be sensitive to relative quantities. We also show that non-ohnologs neighboring ohnologs are unlikely to have CNVs, resulting in ohnolog-rich regions in vertebrate genomes being CNV deserts. Our results suggest that the genomic location of ohnologs is a determining factor in the retention of CNVs and that dosage-balanced ohnologs are likely to cause the deleterious effects of CNVs in these regions. We propose that investigating CNV of genes in CNV deserts is an efficient means to find disease-related CNVs.