Zrsr2 is essential for hematopoiesis and splicing of minor introns in RNA and protein processing genes in zebrafish

ZRSR2 is an essential splicing factor involved in 3'-splice site recognition as a component of both the major and minor spliceosomes that mediate splicing of U2- and U12-type introns, respectively. Transcriptome analysis of ZRSR2-mutated bone marrow samples and ZRSR2-knockdown cell lines has revealed its essential role in the minor spliceosome. We established a zrsr2-knockout zebrafish line, termed zrsr2hg129/hg129 (p.Trp167Argfs*9) using CRISPR/Cas9 technology. Global transcriptome analysis of 3 dpf zrsr2hg129/hg129 embryos revealed that loss of Zrsr2 leads to aberrant retention of minor introns in about one third of all minor intron-containing genes in zebrafish. Interestingly, these genes showed an enrichment for the RNA and protein processing pathways. Overall, our study has demonstrated that the role of Zrsr2 as a component of the minor spliceosome is conserved in zebrafish. Overall design: mRNA from decapitated 3dpf wild-type and zrsr2hg129/hg129 zebrafish embryos