Maternal factor that plays a role in epigenetic chromatin reprogramming during early development of the zygote (PubMed:23560077, PubMed:28930672). Involved in the regulation of gametic DNA demethylation by inducing the conversion of the modified genomic base 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC) (PubMed:23560077, PubMed:28930672). Interacts with histone H3 (PubMed:23560077). Interacts with histone H4 (PubMed:23560077). Interacts with METTL23 (PubMed:28930672). Localizes in female and male zygote pronucleus (PubMed:23560077, PubMed:16571911). Associates preferentially with the paternal chromatin during zygote development (PubMed:23560077). Expressed in ovary and testis (PubMed:16571911). Expressed in spermatocytes I in the pachytene stage, round spermatids, and elongated spermatids (PubMed:16571911). Expressed in the germinal vesicle (GV) stage and stage 2 meiosis (MII) oocytes and pre-implantation embryos until blastocyst stage (at protein level) (PubMed:16571911, PubMed:23560077). No visible phenotype (PubMed:28930672). Mice were born at the expected Mendelian ratio and show no overt phenotype (PubMed:28930672). Zygotes however display strongly reduced levels of 5-hydroxymethylcytosine (5hmC) (PubMed:28930672).