Project description:The organ of Corti, located in the floor of the scala media of the cochlea, acts as the primary sensory transducer of sound in mammals. This remarkable structure comprises a highly diverse cellular mosaic that includes two unique types of mechanosensory hair cells and an undefined number of associated supporting cell types. All of these cells are believed to arise from a developmental equivalence group referred to as the prosensory domain that is similarly thought to arise from a proneurosensory population that develops in the anterior-ventral region of the otocyst. The results of both classical embryologic manipulations and modern molecular genetic experiments suggest that otocyst precursor cells proceed through several rounds of lineage restriction that progressively specify subsets of cells as prosensory cells and ultimately as either hair cells or supporting cells. However, the relatively small sizes of the otocyst and inner ear have hindered efforts to determine the full diversity of cell types within the mature cochlea and to identify the transitional cell types that exist during development. The recent development of droplet-based methods for isolation and subsequent transcriptional profiling of individual cells provides a potential method to address both of these challenges. Therefore, we dissected, dissociated and then captured over 27,000 epithelial cells from the developing cochlear duct at specific time points between E14 and P7.
Project description:Otic Mesenchyme Cells (OMCs) are the numerous cell type during cochlear development. We used single cell RNA sequencing (scRNA-seq) to analyze the diversity of OMCs during cochlear development
Project description:Juvenile and mature mouse cochleae contain various low-abundant, vulnerable sensory epithelial cells embedded in the calcified temporal bone, making it challenging to profile the dynamic transcriptome changes of these cells during maturation at the single-cell level. Here we performed the 10X Genomics single-cell RNA sequencing (scRNA-seq) of mouse cochleae at postnatal days 14 (P14) and 28. We attained the transcriptomes of multiple cell types, including hair cells, supporting cells, spiral ganglia, stria fibrocytes, and immune cells. Our hair cell datasets are consistent with published transcripts from bulk RNA seq and scRNA-seq. We also mapped known deafness genes to corresponding cochlear cell types. Importantly, pseudotime trajectory analysis revealed that inner hair cells peak their maturation at P14 while outer hair cells continue to develop until P28. We further identified and confirmed a long noncoding RNA gene Miat expressed during maturation in cochlear hair cells and spiral ganglia neurons. Our transcriptomes of juvenile and mature mouse cochlear cells provided the sequel to those previously published at late embryonic and early postnatal ages and will be valuable resources to investigate cochlear maturation at single-cell resolution.
Project description:Mutations in approximately 30 genes have been linked to cochlear malformations, but the contribution of noncoding regulatory elements remains largely unclear. This study investigates the function of distal enhancer elements in the transcriptional regulation of GDF6, a gene implicated in cochlear development. Using mouse models with targeted deletions, human inner ear organoids, and CRISPR interference (CRISPRi), we identified a downstream regulatory interval harboring a developmental enhancer required to maintain GDF6 expression during otic epithelial maturation and cochlear morphogenesis. To characterize cellular composition and chromatin accessibility changes in patient (166-101) versus control (CA-26) iPSC-derived otic progenitor cells, we performed joint single-nucleus RNA-seq and ATAC-seq (10X Genomics Multiome) on CD271+ enriched populations.