Recent analysis has suggested that mutation bias exists in genomic DNA and the concept of ‘‘hotspots’’ in the genome may be of great importance in radiation protection in the human genome. The work of Kim et al. (2004) revealed several prominent hotspots in each of the mutagen-induced groups of Escherichia coli. Peter et al. (2005) studied a large
number of repetitive elements deposited into the human genome after irradiation, and for all types of substitution they observed substantially more hotspots than coldspots,
with hotspots showing substantial clustering over tens of Mbps. Until now, the analysis of hotspots has mainly focused on radiation protection research in animal genomes.
In our research, whole genome level analysis of the patterns of space mutation in rice plants suggests that space environment-induced mutations in rice genomes may share a common mechanism with other types of mutagens and occur preferentially at genomic hotspots. Our results also
imply that the polymorphic sites in genomes are potential ‘‘hotspots’’ for mutations induced by space environment.