Functional study of m6A methyltransferase METTL16 in drosophila development

ABSTRACT: N6-methyladenosine (m6A) is one of the most prevalent RNA modifications in eukaryotes. The METTL16 enzyme catalyzes the m6A modification at position 43 of U6 snRNA, which is very important for the 5'-splice site recognition by U6 during pre-mRNA splicing. Loss of METTL16 results in the death of mouse early embryos, making it difficult to study the function of METTL16 in development. Here we characterize METTL16 in the context of Drosophila melanogaster development. We showed that dMETTL16 localizes in nuclei of all endoreduplicating cells, such as cells in salivary glands, with a pattern coinciding with the replication timing. In addition, dMETTL16 is present in diploid cells of the gonad, suggesting that it plays a role in gonadal development. To further determine the function of dMETTL16, we used the CRISPR/Cas9 system to construct dMETTL16 mutations and discovered that mutants are semilethal at the larval stage while surviving adults are female sterile. More interestingly, a 50% reduction of U6 gene dosage leads to complete lethality of dMETTL16 mutants at the larval stage suggesting that loss of U6 function is one of the primary defects in the mutants. Using a novel antibody-based in vitro methylation assay, we proved that U6 is a substrate of dMETTL16. To determine whether the phenotypes depend on m6A methylase activity, we constructed point mutations of the active site of dMETTL16, and discovered that ovarian development was restored while maternal lethality ensures. These results suggest that dMETTL16 has important functions that are independent of its methyltransferase activity. Our study establishes Drosophila as a genetically tractable model for the study of dMETTL16’s function and can be explored to uncover additional dMETTL16 m6A targets.

ORGANISM(S): Drosophila melanogaster

PROVIDER: GSE271111 | GEO | 2026/07/05

REPOSITORIES: GEO