Table I. Expression analysis of C2 type I MADS-box genes in ovules and seeds.
A, Antipodal cells; C, central cell; ENC, signal is stronger in the chalazal region than in the peripheral and micropylar regions; ENM, signal is stronger in the micropylar region and not detected or weak in the chalazal region; ENM&C, signal is stronger in the micropylar and chalazal regions than in the peripheral region; ENM&P, signal is present only in the micropylar and peripheral regions; FG, female gametophyte; ND, not determined; ne, no detectable expression; s, synergid cells; SBE, single-base extension with fluorescently labeled dideoxyribonucleotide triphosphates (ddNTPs).
| Expression Cluster |
Reporter Analysisa |
Imprinting Analysisb |
||||
|---|---|---|---|---|---|---|
| Gene | Arabidopsis Genome Initiative No. | qPCRc | FG | Endosperm | Reporterc | SBE |
| AGL23 | AT1G65360 | C2.1 | C, s | ENM&C | Biallelic | Paternal |
| AGL28 | AT1G01530 | C2.1 | c | ENM&C | Biallelic | Biallelic |
| AGL35 | AT5G26630 | C2.1 | ne | ENM&C | Biallelic (biallelic) | Biallelic |
| AGL36 | AT5G26650 | C2.1 | ne | ENM | Maternal (maternal) | Maternal |
| AGL46 | AT2G28700 | C2.1 | c | ENM&P | Biallelic | Biallelic |
| AGL48 | AT2G40210 | C2.1 | ne | ENM | Biallelic | Biallelic |
| AGL58 | AT1G28450 | C2.1 | ne | ENM | Biallelic | ND |
| AGL59 | AT1G28460 | C2.1 | ne | ENM | Biallelic | ND |
| AGL64 | AT1G29962 | C2.1 | ne | ENM | ND | Biallelic |
| AGL96 | AT5G06500 | C2.1 | ne | ENM | Maternal | Maternal |
| AGL95 | AT2G15660 | C2.1 | ND | ND | ND | Biallelic |
| AGL90 | AT5G27960 | C2.1 | ne | ENM | Maternal | Maternal |
| PHE1 | AT1G65330 | C2.2 | ne | ENM&C | Biallelic (paternal) | Paternal |
| PHE2 | AT1G65300 | C2.2 | c | ENM&C | Biallelic | Biallelic |
| AGL40 | AT4G36590 | C2.2 | ne | ENM&C | Biallelic | Biallelic |
| AGL45 | AT3G05860 | C2.2 | A | ENC | Biallelic | Biallelic |
| AGL49 | AT1G60040 | C2.2 | ND | ND | ND | ND |
| AGL91 | AT3G66656 | C2.2 | ne | ENC | Biallelic | ND |
GFP/YFP reporter signals were analyzed 1 DAE (corresponding to the mature female gametophyte) and at flower stage 16 (corresponding to coenocytic endosperm stages V and VI). Consistent (uppercase) or sporadic (lowercase) GFP expression was observed in the female gametophyte, while expression in the endosperm was consistent.
Imprinting of paternal or maternal allele-specific expression was determined using reporter lines and/or SBE analysis.
The genes significantly up-regulated at 5 DAP in the swn;mea mutant are in boldface.
All genes were analyzed in promoter fusion reporter lines except for three genes also analyzed in full-length gene fusion (indicated by parentheses).