m6A controls neurogenesis and sex determination in Drosophila via its nuclear reader protein YT521-B [RNA-Seq, whole flies]. Drosophila melanogaster

N6-methyladenosine RNA (m6A) is the most abundant internal mRNA modification in mammals. While its role in the regulation of posttranscriptional gene expression is beginning to be unveiled, its function during development of complex organisms is poorly understood. Here, we identify Spenito as a novel member of the methyltransferase complex and show that m6A in Drosophila is necessary for proper synaptic growth, and in regulation of early steps of pre-mRNA splicing. Splicing of Sex-lethal and of its downstream targets are defective in animals lacking m6A, revealing also important roles in sex determination and dosage compensation. Finally, we implicate the nuclear m6A reader protein, YT521-B, as a crucial effector of m6A modifications in vivo. Altogether, our work provides important novel insights into m6A biology through identification and characterization of both m6A-writing and -reading proteins in Drosophila and their effects on splicing, neurogenesis and sex-determination within the context of the whole animal. Overall design: RNA seq in Drosophila melanogaster (flies) (3 Conditions, triplicates)

N6-甲基腺嘌呤RNA（m6A）是哺乳动物体内最丰富的mRNA内部修饰形式。其在转录后基因表达调控中的作用正逐步被揭示，但在复杂生物体发育过程中的功能仍未得到充分解析。本研究鉴定出Spenito为甲基转移酶复合物的新成员，并证实果蝇体内的m6A对于正常突触生长以及前体mRNA（pre-mRNA）剪接的早期调控步骤不可或缺。在缺失m6A的果蝇个体中，性别致死基因（Sex-lethal）及其下游靶基因的剪接存在缺陷，这也揭示了m6A在性别决定与剂量补偿中的重要作用。最后，本研究证实核内m6A识别蛋白YT521-B是体内介导m6A修饰功能的关键效应分子。综上，本研究通过鉴定并表征果蝇体内的m6A修饰写入与读取相关蛋白，阐明了二者对剪接、神经发生以及个体整体水平上性别决定过程的调控效应，为m6A生物学领域提供了重要的全新研究视角。
实验设计：对黑腹果蝇（果蝇）开展RNA测序实验，设置3种实验条件，每组均设置三次生物学重复。