Table 1. Biallelic Expression of SPE Genes in the Reciprocal Hybrids B73xMo17 and Mo17xB73.

Group of SPE Genesa	No. of SPE Genes	No. of SPE Genes with SNPs	No. of SPE Genes with SNPs, PAVs Excludedb	Subset of SPE Genes Expressing Both Parental Alleles
				B73xMo17		Mo17xB73
				≥1 Read	≥10 Reads	≥1 Read	≥10 Reads
SPE_B-MZ	510	399	374	73	0	74	0
SPE_M-MZ	581	525	–	116	2	132	4
SPE_B-EZ	472	381	356	70	0	62	0
SPE_M-EZ	565	502	–	134	2	124	2
SPE_B-C	599	475	451	95	0	97	0
SPE_M-C	661	611	–	176	3	197	2
SPE_B-S	607	488	457	107	1	117	1
SPE_M-S	680	611	–	183	2	169	3

An allele was considered to be expressed with either one read or 10 reads minimum. PAVs were excluded from all SPE_B genes.

^aSPE_B, gene expressed in B73 and hybrids but not in Mo17; SPE_M, gene expressed in Mo17 and hybrids but not in B73. B, B73; M, Mo17; MZ, meristematic zone; EZ, elongation zone; C, cortex; S, stele.

^bPAVs (genes present in the B73 genome but absent from the Mo17 genome).