Similar Datasets
Project description:NRL (Neural retina leucine zipper) is a key regulator of the fate determination and gene expression of rod photoreceptors in the retina of many vertebrates. In this study, we observed a unique retinal phenotype in the nrl knockout zebrafish model characterized by reduced rods with shortened outer segments and gradually increased green-cones in adulthood. By tracing and comparing the developmental processes of WT and nrl knockout rods, we found there might be two waves of rod genesis distinguished as nrl-dependent and independent with different starting times. To reveal the underlying cellular and molecular mechanisms, bulk and single-cell RNA-seq were performed. The changes in gene expression and cell proportion of rods and cones agreed well with our histological and immunofluorescence studies. Interestingly, we found that rods exhibited noticeable heterogeneities in the gene expression patterns, and a part of rods in nrl knockout zebrafish misexpressed the green-cone genes, reflecting a hybrid status of rod and green-cone. Furthermore, we identified mafba as a novel regulator of rod genesis, which was responsible for the development of rods in nrl knockout zebrafish. Our study will largely improve the current understanding of the developmental processes and regulatory mechanisms of rods in zebrafish and probably other species, and may facilitate future studies in the fields of retinal development and retinal degeneration.
2020-10-27 | GSE160140 | GEO
Project description:NRL (Neural retina leucine zipper) is a key regulator of the fate determination and gene expression of rod photoreceptors in the retina of many vertebrates. In this study, we observed a unique retinal phenotype in the nrl knockout zebrafish model characterized by reduced rods with shortened outer segments and gradually increased green-cones in adulthood. By tracing and comparing the developmental processes of WT and nrl knockout rods, we found there might be two waves of rod genesis distinguished as nrl-dependent and independent with different starting times. To reveal the underlying cellular and molecular mechanisms, bulk and single-cell RNA-seq were performed. The changes in gene expression and cell proportion of rods and cones agreed well with our histological and immunofluorescence studies. Interestingly, we found that rods exhibited noticeable heterogeneities in the gene expression patterns, and a part of rods in nrl knockout zebrafish misexpressed the green-cone genes, reflecting a hybrid status of rod and green-cone. Furthermore, we identified mafba as a novel regulator of rod genesis, which was responsible for the development of rods in nrl knockout zebrafish. Our study will largely improve the current understanding of the developmental processes and regulatory mechanisms of rods in zebrafish and probably other species, and may facilitate future studies in the fields of retinal development and retinal degeneration.
2020-10-27 | GSE160138 | GEO
Project description:Nrl-dependent and independent rod photoreceptor development in zebrafish
| PRJNA672094 | ENA
Project description:Nrl-dependent and independent rod photoreceptor development in zebrafish [scRNA-Seq]
| PRJNA672101 | ENA
Project description:Nrl-dependent and independent rod photoreceptor development in zebrafish [RNA-Seq]
| PRJNA672100 | ENA
Project description:Specification of retinal rod photoreceptors is determined by several different transcription factors that activate expression of rod-specific genes and repress expression of cone photoreceptor-specific genes. The mechanism by which this dual regulation occurs is unclear. We have found that Pias3, a transcriptional coregulator and E3 SUMO ligase that is selectively expressed in developing photoreceptors, promotes the differentiation of rod photoreceptors while preventing rods from adopting cone photoreceptor-like characteristics. Pias3 binds the photoreceptor-specific transcription factors Crx and Nr2e3 and is specifically targeted to the promoters of photoreceptor-specific genes. Pias3 SUMOylates Nr2e3, converting it into a potent repressor of cone-specific gene expression. Rod- and cone-specific promoters are bound by hyperSUMOylated proteins in rod photoreceptors, and blocking SUMOylation in photoreceptors results in cells with morphological and molecular features of cones and an absence of rod-specific markers. Our data thus identify Pias3-mediated SUMOylation of photoreceptor-specific transcription factors as a key mechanism of rod specification.
| S-EPMC2701228 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2014-08-04 | E-GEOD-58084 | biostudies-arrayexpress
Project description:Neural retina leucine zipper (NRL) is an essential gene for the fate determination and differentiation of the precursor cells into rod photoreceptors in mammals. Mutations in NRL are associated with the autosomal recessive enhanced S-cone syndrome and autosomal dominant retinitis pigmentosa. However, the exact role of Nrl in regulating the development and maintenance of photoreceptors in the zebrafish (Danio rerio), a popular animal model used for retinal degeneration and regeneration studies, has not been fully determined. In this study, we generated an nrl knockout zebrafish model via the CRISPR-Cas9 technology and observed a surprising phenotype characterized by a reduced number, but not the total loss, of rods and over-growth of green cones. We discovered two waves of rod genesis, nrl-dependent and -independent at the embryonic and post-embryonic stages, respectively, in zebrafish by monitoring the rod development. Through bulk and single-cell RNA sequencing, we characterized the gene expression profiles of the whole retina and each retinal cell type from the wild type and nrl knockout zebrafish. The over-growth of green cones and mis-expression of green-cone-specific genes in rods in nrl mutants suggested that there are rod/green-cone bipotent precursors, whose fate choice between rod versus green-cone is controlled by nrl. Besides, we identified the mafba gene as a novel regulator of the nrl-independent rod development, based on the cell-type-specific expression patterns and the retinal phenotype of nrl/mafba double-knockout zebrafish. Gene collinearity analysis revealed the evolutionary origin of mafba and suggested that the function of mafba in rod development is specific to modern fishes. Furthermore, the altered photoreceptor composition and abnormal gene expression in nrl mutants caused progressive retinal degeneration and subsequent regeneration. Accordingly, this study revealed a novel function of the mafba gene in rod development and established a working model for the developmental and regulatory mechanisms regarding the rod and green-cone photoreceptors in zebrafish.
| S-EPMC8926279 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2014-08-14 | E-GEOD-55393 | biostudies-arrayexpress
Project description:PurposeNRL is an influential transcription factor and central to animal modeling in ophthalmology. Disrupting NRL abrogates rod development and produces an excess of S-cones (also known as "UV cones" or "short-wavelength-sensitive1 [SWS1] cones"). Strikingly, mutations in zebrafish tbx2b produce the exact opposite phenotypes (excess rods and loss of SWS1 cones). We sought to define what genetic relationship exists, if any, between these transcription factors. We also infer whether these two phenotypes (altered rod abundance and altered SWS1 cone abundance) are independent versus inter-related.MethodsZebrafish mutants were bred to disrupt nrl and tbx2b in concert. Rods and SWS1 cones were quantified and characterized at ultrastructural and transcriptional levels.ResultsConsidering single mutant zebrafish, we confirmed previously established phenotypes and noted that the number of rods lost in nrl-/- mutants is reflected by a concomitant increase in SWS1 cone abundance. The tbx2b-/- mutants present the opposite phenotype(s) but exhibit a similar trade-off in cell abundances, with lots of rods and a concomitant decrease in SWS1 cones. Double mutant nrl-/-;tbx2b-/- zebrafish recapitulate the nrl-/- mutant phenotype(s).ConclusionsThe tbx2b is thought to be required for producing SWS1 cones in zebrafish, but this can be over-ridden when nrl is absent. Regarding the altered cell abundances observed in either tbx2b-/- or nrl-/- mutants, the alterations in rod and SWS1 cones appear to not be two separate phenotypes but are instead a single intertwined outcome. The tbx2b and nrl are in an epistatic relationship, with nrl phenotypes dominating, implying that tbx2b is upstream of nrl in photoreceptor cell fate determination.
| S-EPMC10810017 | biostudies-literature