Table 2. Maternal-effect genes found by genetic perturbation experiments with predominant developmental arrest at the zygote stage.

Gene/aliases	KD/KO	Developmental role	References
Gas6/growth arrest specific 6	KD by RNAi	Maternal cytoplasmic maturation, sperm chromatin decondensation, pronuclear formation	Kim et al., 2011, 2018
Hira/histone cell cycle regulation defective homolog A	cKO using (Tg)Zp3-Cre and (Tg)Gdf9-Cre	Transcription, replication, paternal nucleosome assembly	Lin et al., 2014; Nashun et al., 2015
Npm2/nucleoplasmin 2	KO	Nuclear and nucleolar organization, chromatin remodeling	Burns et al., 2003
Scc1 (Rad21)/double-strand-break repair protein rad21 homolog	cKO using (Tg)Zp3-Cre	Mitotic sister chromatid cohesion, repair of Tet3-dependent paternal DNA lesions, higher-order chromatin structure	Ladstätter and Tachibana-Konwalski, 2016; Gassler et al., 2017
Zar1/zygote arrest 1	KO	RNA processing, pronuclear fusion	Wu et al., 2003; Hu et al., 2010
Ago2/argonaute 2, RISC catalytic component	cKO using (Tg)Zp3-Cre	miRNA homeostasis, post-transcriptional gene silencing of maternal factors	Kaneda et al., 2009; conflicting arrest after two-cell (Morita et al., 2007; Lykke-Andersen et al., 2008)
Hsf1/heat shock factor 1	KO	Transcription, redox-homeostasis	Christians et al., 2000; Bierkamp et al., 2010

cKO, conditional KO; KD, knockdown.