Fig. 8.

Summary of the roles of DUO1 in Arabidopsis germline development. The GC forms a cytoplasmic extension and elongates during bicellular pollen development (a–d). DUO1 regulates both GC division (black arrow) and SC specification (green arrow). In mutant duo1 pollen, the GC fails to elongate and divide but forms a cytoplasmic extension (f–j), like the GC in wild-type pollen (a–e). DUO1, therefore, has a key role in GC elongation (orange arrow). Examples of direct DUO1-target genes are shown; HTR10, HISTONE THREE RELATED 10; GEX2, GAMETE EXPRESSED 2; HAP2/GCS1, HAPLESS 2/GENERATIVE CELL SPECIFIC 1