Functional analysis of new human Bardet-Biedl syndrome loci specific variants in the zebrafish model

• Published in: Scientific reports 2019-09, Vol.9 (1), p.12936-12936, Article 12936
• Main Authors: Castro-Sánchez, Sheila, Suarez-Bregua, Paula, Novas, Rossina, Álvarez-Satta, María, Badano, Jose L., Rotllant, Josep, Valverde, Diana
• Format: Article
• Language: English
• Subjects: 14/19; 14/63; 38/32; 45/41; 45/70; 45/90; 631/208/2489/144; 631/208/737; 64/116; 96/1; 96/63; Animal models; Animals; Bardet-Biedl syndrome; Bardet-Biedl Syndrome - genetics; Bardet-Biedl Syndrome - pathology; Bioinformatics; Biomedical research; Cilia; Cognitive ability; Cohort Studies; Cytoskeletal Proteins - antagonists & inhibitors; Cytoskeletal Proteins - genetics; Cytoskeletal Proteins - metabolism; Danio rerio; Disease Models, Animal; Embryo, Nonmammalian - metabolism; Embryo, Nonmammalian - pathology; Embryos; Female; Genes; Genetic engineering; Genetic Loci; Group II Chaperonins - antagonists & inhibitors; Group II Chaperonins - genetics; Group II Chaperonins - metabolism; High-Throughput Nucleotide Sequencing; Humanities and Social Sciences; Humans; Male; Microtubule-Associated Proteins - antagonists & inhibitors; Microtubule-Associated Proteins - genetics; Microtubule-Associated Proteins - metabolism; multidisciplinary; Mutation; Next-generation sequencing; Oligonucleotides, Antisense - administration & dosage; Pathogenicity; Pathogens; Patients; Pedigree; Phenotype; Phenotypes; Phosphate-Binding Proteins - antagonists & inhibitors; Phosphate-Binding Proteins - genetics; Phosphate-Binding Proteins - metabolism; Proteins; Science; Science (multidisciplinary); Zebrafish
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-49217-7

The multiple genetic approaches available for molecular diagnosis of human diseases have made possible to identify an increasing number of pathogenic genetic changes, particularly with the advent of next generation sequencing (NGS) technologies. However, the main challenge lies in the interpretation of their functional impact, which has resulted in the widespread use of animal models. We describe here the functional modelling of seven BBS loci variants, most of them novel, in zebrafish embryos to validate their in silico prediction of pathogenicity. We show that target knockdown (KD) of known BBS (BBS1 , BB5 or BBS6) loci leads to developmental defects commonly associated with ciliopathies, as previously described. These KD pleiotropic phenotypes were rescued by co-injecting human wild type (WT) loci sequence but not with the equivalent mutated mRNAs, providing evidence of the pathogenic effect of these BBS changes. Furthermore, direct assessment of cilia located in Kupffer’s vesicle (KV) showed a reduction of ciliary length associated with all the studied variants, thus confirming a deleterious effect. Taken together, our results seem to prove the pathogenicity of the already classified and unclassified new BBS variants, as well as highlight the usefulness of zebrafish as an animal model for in vivo assays in human ciliopathies.