Location: Crop Germplasm ResearchTitle: Distribution and evolution of cotton fiber development genes in the fibreless Gossypium raimondii genome
|XU, ZHANYOU - Iowa State University|
|YU, JING - Washington State University|
|BEAVIS, WILLIAM - Iowa State University|
|MAIN, DORRIE - Washington State University|
Submitted to: Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/11/2015
Publication Date: 6/2/2015
Citation: Xu, Z., Yu, J., Kohel, R.J., Percy, R.G., Beavis, W.D., Main, D., Yu, J. 2015. Distribution and evolution of cotton fiber development genes in the fibreless Gossypium raimondii genome. Genomics. 106:61-69.
Interpretive Summary: Understanding the genetic mechanism of the cotton fiber development is essential for improvement of fiber yield and fiber quality. In cotton this is complicated by two component sets of genetic makeup, or genomes, controlling fiber initiation, development, and maturation. There is increasing evidence that these two genomes do not contribute equally to the various phases of fiber development. In this study we determined that one ancestral genome of commercial cotton (referred to as D), has provided many fiber development genes after its merger with the other ancestral genome called A. This finding is unexpected, due to the fact that the ancestor D genome does not produce any spinnable fiber. These insights into the evolution of the cotton genomes and the distribution of fiber development genes will guide efforts to manipulate important genes enhancing fiber yield and quality. Identification of chromosome regions associated with fiber genes will allow for accelerated and efficient breeding through marker-assisted selection for the maximum accumulation of desired genes.
Technical Abstract: Cotton fibers represent the largest single cell in the plant kingdom, and they have been used as a model to study cell function, differentiation, maturation, and cell death. The cotton fiber transcriptome can be clustered into two genomic regions: conserved and recombination hotspots. Genetic linkage maps are constructed based on the recombination of adjacent DNA markers or fragments in recombination hotspots, and they are the basis for marker assisted selection for breeding. This study investigated the distribution and evolution of fiber development Unigenes anchored to recombination hotspot regions among tetraploid cotton (Gossypium hirsutum) At and Dt subgenomes, and within the diploid cotton (G. raimondii) D genome sequenced independently by both the Beijing Genomics Institute (BGI) and the Joint Genome Institute (JGI). Results from the comparisons between the 13 chromosomes of At and D, and the 13 chromosomes of Dt and D show that 1) the diploid cotton D genome provides many fiber development genes after the merger of the two diploid genomes "A" from G. arboreum and "D" from G. raimondii although the D genome itself does not produce any spinnable fiber; 2) the At vs. D comparison has higher co-linearity for fiber development Unigenes than does the Dt vs. D in the recombination hotspots of the tetraploid cotton genome and the diploid D genome. This is the first report that in recombination hotspots of the tetraploid genome, fiber development genes have higher similarity between At and D than that between Dt and D chromosome pairs. This finding provides new insights into cotton genome evolution and distribution of fiber development Unigenes and will guide further efforts on agronomically important genomic regions for genetic improvement of fiber yield and quality.