Polycistronic microRNA clusters certainly are a common feature of vertebrate genomes. miRNA gene Pazopanib HCl with important roles in development and disease6. consists of six highly conserved miRNAs belonging to four seed families (Fig. 1a). In mice, targeted deletion of the whole cluster causes a wide array of developmental defects affecting multiple organs and systems7, while in humans germline mono-allelic microdeletions involving are responsible for Pazopanib HCl the developmental defects observed in a subset of patients affected by Feingold Syndrome8 (FS2; OMIM 614326), an autosomal dominant disease characterized by short stature and variable combinations of craniofacial abnormalities, limb and digit malformations, gastro-intestinal atresia, and learning disabilities9. Figure 1 Generation Pazopanib HCl of an allelic series of miR-17~92 mutant mice is also a human oncogene. Focal amplifications of its locus are frequent in human diffuse large B-cell lymphomas10 and its components are overexpressed in many human cancers11C16 at least partially as result of direct transcriptional activation by members of the Myc family of oncogenic transcription factors17. In addition, ectopic expression of accelerates or initiates tumor formation in several mouse models of human cancer12,18C24. We reasoned that the multiple phenotypes caused by deletion could be used to experimentally determine the extent of functional cooperation among the miRNAs encoded by a polycistronic cluster. Here we report the Pazopanib HCl generation of an allelic series of mutant mice and integrate their phenotypic characterization with RNA-seq analysis showing the consequences of selective miRNA inactivation on gene expression in the developing embryo. Our results provide novel insights into the biology of this CGB important oncogenic miRNA cluster and pave the way for further mechanistic studies. RESULTS Generation of an allelic series of miR-17~92 We used homologous recombination in mouse embryonic stem cells to generate six alleles (Fig. 1b, Supplementary Fig. 1a), each characterized by the deletion of genomic sequences corresponding to one or more of its pre-miRNAs. Four alleles harbor the deletion of the components of single seed families: alleles were detected by small RNA sequencing (data not shown). Perinatal lethality, cardiac defects, and lung hypoplasia Homozygous deletion of results in fully penetrant perinatal lethality, a phenotype that has been attributed to severe lung hypoplasia and defective cardiac development7 (Table 1 and Supplementary Fig. 2). By contrast, heterozygous intercrosses of the single-seed mutants yielded viable homozygous adults at expected Mendelian ratios and even combined deletion of the miR-17 and miR-18 seed families was compatible with postnatal survival. For each of these strains, crosses between homozygous animals produced viable offspring (data not shown). Strikingly, we observed perinatal lethality only in locus in mice phenocopies several of the key features of FS2, including size and digit abnormalities8. To define the relative contribution of each seed family to the pathogenesis of this syndrome, we examined mice from the allelic series. Homozygous animals for each of the four single-seed mutant alleles were smaller than age- and sex-matched wild type controls (Fig. 2a, 2b). This phenotype was most severe in animals was comparable to that of mice, but not mice homozygous for the other single-seed mutant alleles, also displayed fusion of the proximal carpal bones. mutant mice showed more serious phenotypes than those holding a deletion of miR-17 by itself, and additional deletion of miR-92a (lack of function mice (Fig. 2c and Supplementary Fig. 3a,b). The function of in FS2 compelled us to help expand analyze skeletal advancement in the lack of the complete cluster or of its specific components (discover Supplementary Dining tables 2C4). In this evaluation we discovered that lack of affected an integral event through the formation from the mammalian skeleton: its patterning along the antero-posterior axis, that leads towards the differentiation of specific skeletal sections27 morphologically,28 (Supplementary Fig. 3c). Homeotic transformations in in patterning from the axial skeleton, recognize the miR-17 seed family members as the primary effector of the function, and offer a direct hyperlink between mutation of.