Mendelian and Non-Mendelian Regulation of Gene Expression in Maize
Figure 5
Four types of unexpected expression patterns between the RILs and their parents.
Type I: genes expressed in both B73 and Mo17, but not expressed in at least 1/10 of the RIL population. Type II: genes not expressed in both B73 and Mo17, but expressed in at least 1/10 of the RIL population. Type III: genes expressed in either B73 or Mo17, have abnormal segregation ratio of expression versus non-expression in RILs, such as 1∶3, 3∶1 etc. Type IIIA are genes tending to be expressed in fewer RILs than the expected 1∶1 ratio while Type IIIB are genes that tend to be expressed in more RILs than the expected 1∶1 ratio. In (A), gene transcripts in the Type I∼III categories were amplified by RT-PCR from RNAs isolated from an independent replication of 10 genotypes from the IBM population. Thirty-five cycles of PCR was conducted for genes GRMZM2G403162 (Type I), GRMZM2G168987 (Type II), GRMZM2G103479 (Type IIIA), GRMZM2G170588 (Type IIIB) and a housekeeping gene (Actin). The number under each band shows the RPKM value in each RIL. (B) RT-PCR assay of individuals in an F2 population from the cross between B73 and Mo17. The corresponding genes from top to bottom are GRMZM2G403162, GRMZM2G053790, GRMZM2G168987, GRMZM2G071808, GRMZM2G103479, and GRMZM2G170588. (C) The percent of RILs with expressed genes with unexpected expression patterns and population mean of their expression levels in the RILs. The x-axis represents the percent of RILs, while the y-axis indicates the log2 score of the population mean of RPKM. The two grey vertical lines mark 10% and 90% of the RILs. (D) The number of genes for each of these unexpected expression patterns and the proportion of syntenic and non-syntenic genes in each expression pattern.