Gene Expansion/Contraction and Species-specific Genes inM. pygmaeas
A total of 37 and 202 gene families significantly (P < 0.05) expanded and contracted in M. pygmaea , respectively, of the 758 and 2,973 that significantly differed among other Lineage II genomes (Fig. 2C ). The significantly expanded and contracted gene families contain 1,231 and 2,476 genes, respectively. The functional annotation of these genes revealed that expanded genes were involved in hyperosmotic salinity response, regulation of defense response to fungus and stomatal movement (Table S6 ). We extracted 5,504 species-specific genes from the expanded and species-specific families in the M. pygmaea genome. These genes were enriched signal transduction, defense response to insect and other organisms (Table S7 ).