Jiang Fangfei, Boylan Michael, Maxwell Dale W, Qureshi Wasay Mohiuddin Shaikh, Rowlands Charlie F, Tenin Gennadiy, Mitchell Karen, Stephen Louise A, Vasconcelos Elton J R, Wang Dapeng, Chen Tong, Zha Junzhe, Liu Jingshu, Althali Nouf, Leordean Dragos V, Gallagher Meurig T, Basu Basudha, Szymanska Katarzyna, Veeraghanta Advait, Keavney Bernard, Humphries Martin J, Ellingford Jamie, Smith David, Johnson Colin A, O'Keefe Raymond T, Roy Sudipto, Hentges Kathryn E
Division of Evolution, Infection and Genomics, BHF Manchester Centre of Research Excellence, School of Biological Sciences, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, M13 9PT, UK.
Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Proteos, 61 Biopolis Drive, Singapore 138673, Singapore.
bioRxiv. 2025 May 27:2025.05.22.654869. doi: 10.1101/2025.05.22.654869.
Cilia function in the left-right organizer (LRO) is critical for determining internal organ asymmetry in vertebrates. To further understand the genetics of left-right asymmetry, we isolated a mouse mutant with laterality defects, from a random mutagenesis screen. mutants carry a missense mutation in the pre-mRNA processing factor, . mutant zebrafish, carrying a protein truncating mutation in , phenocopy the laterality defects of mutants. mutant mouse and fish embryos have increased expression of an alternative transcript encoding the cilium-associated protein, ARL13B, that lacks exon 9. In zebrafish, over-expression of the transcript lacking exon 9 perturbed cilium formation and caused laterality defects. The shorter ARL13B protein isoform lacked interactions with intraflagellar transport proteins. Our data suggest that PRPF8 plays a prominent role in LRO cilia by through the regulation of alternative splicing of ARL13B, thus uncovering a new mechanism for cilia-linked developmental defects.
纤毛在左右组织者（LRO）中的功能对于确定脊椎动物内部器官的不对称性至关重要。为了进一步了解左右不对称的遗传学，我们从一个随机诱变筛选中分离出了一个具有偏侧性缺陷的小鼠突变体。突变体在mRNA前体加工因子中携带一个错义突变。携带在中发生蛋白质截短突变的突变斑马鱼，表现出与突变体相似的偏侧性缺陷。突变小鼠和鱼类胚胎中，编码纤毛相关蛋白ARL13B且缺少外显子9的可变转录本的表达增加。在斑马鱼中，缺少外显子9的转录本的过表达扰乱了纤毛形成并导致偏侧性缺陷。较短的ARL13B蛋白异构体缺乏与鞭毛内运输蛋白的相互作用。我们的数据表明，PRPF8通过调节ARL13B的可变剪接在LRO纤毛中发挥重要作用，从而揭示了一种与纤毛相关的发育缺陷的新机制。
