Chromosome Duplication Causing Gene-Dosage-based Effects on the Gene Expression Level in Gossypium Hirsutum-Gossypium Australe Addition Lines

Polyploidization, or whole-genome duplication, leads to gene expression changes that drive the evolution of many plants and some animals. However, the role of the dosage effect on gene expression changes following genome duplication remains unclear. Here, severalGossypium hirsutum-Gossypium australealien chromosome addition lines (ALs) were developed that contained a single (MA) or a pair (DA) ofG. australechromosomes on theG. hirsutumbackground, which can be regarded as aG. australechromosome duplication, to mimic genome duplication and to elucidate the short-term effects of chromosome duplication on gene expression changes. Therefore, the profile ofG. australegene expression was investigated in three pairs of MAs and DAs (2G, 3G, and 7G). Our results suggest that dosage-dependent and -independent genes are enriched with genes of different functional categories. The dosage-dependent genes were enriched in primary metabolic activities; whereas the dosage-independent genes were enriched in stress responses, cell signaling, and the endomembrane system. Implication on possible differences in dosage-dependent and independent genes in employing cis- and trans-regulation are also discussed. These results will provide new insights into the mechanisms by which gene-dosage affects expression changes induced by genome duplications.