Fig. 8

Expression profile of MULE-derived putative genes in O. sativa ssp. japonica. a Proportion of MULE-derived putative genes expressed across seven tissues with different evolutionary ages (Asian genic-MULEs, AA genic-MULEs, AB genic-MULEs, and all genic-MULEs). A higher proportion of the MULE-derived putative genes are expressed in mature pollen compared with all annotated Oryza genes (Fisher exact test, *P = 0.0183 for Asian MULE-derived putative genes, ***P = 0.0006463 for AA MULE-derived putative genes, **P = 0.001295 for all MULE-derived putative genes). b Heatmap of relative gene expression levels for MULE-derived putative genes versus all annotated Oryza genes. These data suggest that MULE-derived putative genes, especially those associated with younger genic-MULEs, are highly expressed in mature pollen compared with all annotated Oryza genes (note that the data size of expressed MULE-derived putative genes from AB genic-MULEs is very small, with only 17 genes detected, which might not, therefore, represent a statistically significant pattern)