Title: Phenotypic mutant library: potential for gene discovery Authors
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: May 1, 2014
Publication Date: July 8, 2014
Citation: Xin, Z., Chen, J., Burow, G.B., Burke, J.J. 2014. Phenotypic mutant library: potential for gene discovery. In: Wang, Y-H, Upadhyaya, H.D., Kole, C., editors. Genetics, Genomics and Breeding of Sorghum. Boca Raton, FL: CRC Press. p. 284-302. Technical Abstract: The rapid development of high throughput and affordable Next- Generation Sequencing (NGS) techniques has renewed interest in gene discovery using forward genetics. The conventional forward genetic approach starts with isolation of mutants with a phenotype of interest, mapping the mutation within a small chromosomal region through linkage analysis, and identifi cation of the gene that carries the expected mutation. Depending on the availability of polymorphic markers in the region around the mutation, it can take years to identify the causal mutation even in model plants, like Arabidopsis and rice. New strategies based on NGS combine linkage analysis of hundred of thousand markers with the identifi cation of the causal gene into one step, greatly increase the effi ciency of gene discovery through forward genetics. Once the mapping populations segregating for the mutant phenotype are established, the causal gene can be identifi ed in a few weeks. With continuous increase in throughput and reduction in sequencing cost, mapping strategies based on NGS will play a major role in gene discovery from mutants with desired phenotypes. Thus, identification of relevant mutants and development of the populations segregating for mutant phenotype will become the limiting factor. We have developed a sorghum (Sorghum bicolor L. Moench) pedigreed mutant library in the inbred line BTx623, which is used for generating the sorghum reference genome sequence. This mutant library displays a wide range of visible phenotype and can serve as a critical resource for rapid discovery of genes critical for yield, adaptation, nutritional quality and biofuel traits.