Regulator of alternative splicing that specifically recognizes and binds N6-methyladenosine (m6A)-containing RNAs (PubMed:29262316, PubMed:29799838). M6A is a modification present at internal sites of mRNAs and some non-coding RNAs and plays a role in the efficiency of mRNA splicing, processing and stability (PubMed:29799838). Acts as a key regulator of exon-inclusion or exon-skipping during alternative splicing via interaction with mRNA splicing factors SRSF3 and SRSF10 (By similarity). Specifically binds m6A-containing mRNAs and promotes recruitment of SRSF3 to its mRNA-binding elements adjacent to m6A sites, leading to exon-inclusion during alternative splicing (By similarity). In contrast, interaction with SRSF3 prevents interaction with SRSF10, a splicing factor that promotes exon skipping: this prevents SRSF10 from binding to its mRNA-binding sites close to m6A-containing regions, leading to inhibit exon skipping during alternative splicing (By similarity). May also regulate alternative splice site selection (By similarity). Also involved in nuclear export of m6A-containing mRNAs via interaction with SRSF3: interaction with SRSF3 facilitates m6A-containing mRNA-binding to both SRSF3 and NXF1, promoting mRNA nuclear export (By similarity). Involved in S-adenosyl-L-methionine homeostasis by regulating expression of MAT2A transcripts, probably by binding m6A-containing MAT2A mRNAs (PubMed:29262316). Also recognizes and binds m6A on other RNA molecules (By similarity). Involved in random X inactivation mediated by Xist RNA: recognizes and binds m6A-containing Xist and promotes transcription repression activity of Xist (By similarity). Also recognizes and binds m6A-containing single-stranded DNA (By similarity). Involved in germline development: required for spermatogonial development in males and oocyte growth and maturation in females, probably via its role in alternative splicing (PubMed:29799838). Interacts with SRSF1. Interacts with SRSF2 (By similarity). Interacts with SRSF3 (PubMed:29799838). Interacts with SRSF7 (PubMed:29799838). Interacts with SRSF10 (By similarity). Interacts with CPSF6 (PubMed:29799838). Interacts with KHDRBS1/SAM68.: Interacts with TRA2B. Interacts with KHDRBS3 (By similarity). Interacts with EMD (By similarity). Interacts with RBMX (By similarity). Interacts with ZCCHC8 (By similarity). Localizes to a novel subnuclear structure, the YT bodies. The YTH domain mediates RNA-binding. Tyrosine phosphorylated. Embryonic lethality (PubMed:29799838). Conditional deletion in germ cells leads to infertility in both males and females: mice are viable and grossly normal but male mice lack any germ cells including mitotic spermatogonia, while female oocyte maturation is arrested at the primary follicle stage (PubMed:29799838). Ythdc1-deficient oocytes contain large cytoplasmic RNA granules, show extensive alternative polyadenylation, thereby altering 3'-UTR length, and massive alternative splicing defects (PubMed:29799838). Truncated N-terminus.