The authors characterized structural variations (SVs) in cotton genomes using comparative genomic analysis, which provided dozens of putative candidate genes to investigate phenotypic differences among the three cotton species. Abundant species-specific SVs in genic regions changed the expression of many important genes, some of which were found to alter expression intensities of genes involved in fatty acid biosynthesis, leading probably to spinnable fiber improvement in (AD)1 compared with A1 or A2, as confirmed by several transgenic cotton lines that overexpressed KCS6 gene.
In conclusion, Huang and colleagues assembled three high-quality cotton reference genomes, and performed systematic and comprehensive genome analysis, especially for cotton A-genomes, which represents a major step toward understanding the evolution of the cotton A genome. They not only have provided the scientific community with valuable genomic and genetic resources to facilitate genetic evolution, comparative genomic analysis, but also will accelerate the process of cotton genetic improvement with advanced methodology and new varieties.