Project description:Purpose. XOPS-mCFP transgenic zebrafish experience a continual cycle of rod photoreceptor development and degeneration throughout life, making them a useful model to investigate the molecular determinants of rod photoreceptor regeneration. The purpose of this study was to compare the gene expression profiles of wild type and XOPS-mCFP retinas in order to identify genes that may contribute to the regeneration of the rods. Methods. Wild type and XOPS-mCFP retinal mRNA was subjected to microarray analysis using the Agilent platform. The Ingenuity Pathway Analysis program was used to identify biologically relevant processes that were significantly represented in the dataset. Expression changes were verified by RT-PCR. Selected genes were further examined during retinal development and in adult retinas by in situ hybridization, immunohistochemistry, and using a transgenic fluorescent reporter line. Results. Over 600 genes displayed significant expression changes in XOPS-mCFP retinas compared to wild type controls. Many of the downregulated genes were associated with phototransduction, whereas upregulated genes were associated with several biological functions, including cell cycle, DNA replication and repair, cell development and cell death. RT-PCR analysis of a subset of these genes confirmed the microarray results. Three transcription factors (sox11b, insm1a, and c-myb) displaying increased expression in XOPS-mCFP retinas were also expressed throughout retinal development and in the persistently neurogenic ciliary marginal zone. Conclusions. This study identified numerous gene expression changes in response to rod degeneration in zebrafish, and further suggests a role for the transcriptional regulators sox11b, insm1a, and c-myb in both retinal development and rod photoreceptor regeneration. Two-condition experiment: wild-type vs. XOPS-mCFP retinas. Four biological replicates for each condition. RNA was prepared from one retina for each sample. Each hybridization was accompanied by a dye-swap control, for a total of eight array hybridizations.
Project description:Purpose. XOPS-mCFP transgenic zebrafish experience a continual cycle of rod photoreceptor development and degeneration throughout life, making them a useful model to investigate the molecular determinants of rod photoreceptor regeneration. The purpose of this study was to compare the gene expression profiles of wild type and XOPS-mCFP retinas in order to identify genes that may contribute to the regeneration of the rods. Methods. Wild type and XOPS-mCFP retinal mRNA was subjected to microarray analysis using the Agilent platform. The Ingenuity Pathway Analysis program was used to identify biologically relevant processes that were significantly represented in the dataset. Expression changes were verified by RT-PCR. Selected genes were further examined during retinal development and in adult retinas by in situ hybridization, immunohistochemistry, and using a transgenic fluorescent reporter line. Results. Over 600 genes displayed significant expression changes in XOPS-mCFP retinas compared to wild type controls. Many of the downregulated genes were associated with phototransduction, whereas upregulated genes were associated with several biological functions, including cell cycle, DNA replication and repair, cell development and cell death. RT-PCR analysis of a subset of these genes confirmed the microarray results. Three transcription factors (sox11b, insm1a, and c-myb) displaying increased expression in XOPS-mCFP retinas were also expressed throughout retinal development and in the persistently neurogenic ciliary marginal zone. Conclusions. This study identified numerous gene expression changes in response to rod degeneration in zebrafish, and further suggests a role for the transcriptional regulators sox11b, insm1a, and c-myb in both retinal development and rod photoreceptor regeneration.
Project description:Purpose: The purpose of this study was to identify transcripts of rod photoreceptors of the zebrafish, an important animal model for vision science. Methods: Zebrafish rods, and non-rod retinal cells of the XOPS:eGFP transgenic line, were separated by cell dissociation and fluorescence-activated cell sorting (FACS), followed by RNA-seq. Validation studies used qPCR and in situ hybridization. Some transcripts were examined in sorted retinal cell populations of larval and juvenile retinas and regenerated adult retinas, and in a zebrafish model for rod degeneration. Results: At a false discovery rate of <0.01, 597 transcripts were upregulated in rods vs. non-rod retinal cells, and 1032 were downregulated. 13,324 total transcripts were detected in rods, including many not previously known to be expressed by rods. Transcripts enriched in rods from adult retinas were also enriched in rods from larval and juvenile retinas, and were also enriched in regenerated rods. Many transcripts enriched in rods were upregulated in retinas of wildtype retinas vs. those of a zebrafish model for rod degeneration. Conclusions: We report the generation of an RNA-seq dataset describing the rod transcriptome of the zebrafish, which is now available as a resource for further studies of rod photoreceptor biology and comparative transcriptomics.
Project description:Retinal degeneration is the leading cause of irreversible blindness. Retinitis pigmentosa (RP) is a genetically heterogenous group of diseases. In the United States, approximately one in 4000 individuals is affected. RP begins with the loss of night vision due to the loss of rod photoreceptor cells. The disease progresses slowly with the loss of peripheral vision, and eventually leads to complete debilitating and irreversible blindness. The first mutation associated with human RP was identified in the gene encoding rhodopsin, the G-protein coupled receptor of rod photoreceptor cells. Mutations within the rhodopsin gene account for significant portion of RP cases. Specifically, mutations of the proline at residue 347 in rhodopsin have been linked to human RP. We are fortunate to have access to the P347S rhodopsin mutant mice. These mice represent an excellent transgenic mouse model of retinal degeneration. The P347S rhodopsin mutation is one of the best studied mutations, yet the mechanism by which the mutation causes degeneration is still unknown. One study has demonstrated that galectin-1 plays a role in degeneration of neuronal processes (1) and another study has shown that expression level of galectin-3 is elevated in retinas of patients with age-related macular degeneration. These studies in conjunction with the availibility of the P347S mutant mice have provided impetus to examine the pathogenesis of retinal degeneration in the context of the possible role of glycans and glycan-binding proteins. The time course of photoreceptor degeneration in the P347S mouse model has been carefully studied. In these mice, degeneration is barely detectable at 1 month of age, yet biochemical evidence suggests that the rod photoreceptor cells have already begun to die. At 4 months of age, approximately half of the rod photoreceptor cells have degenerated. To distinguish involvement of glycogens at the various stages of retinal degeneration, we have collected retinas of wild type and the mutant mice at four time points (1, 2, 3, and 4 months of age). This will allow us to identify the genes that target early, mid- and late stages of the retinal degeneration process. Thus we request the analysis of total 24 samples as specified below: Age Group (months) Mice No of samples at each time point 1 Wild type 3 2 Wild type 3 3 Wild type 3 4 Wild type 3 1 P347S 3 2 P347S 3 3 P347S 3 4 P347S 3 Total 24.
Project description:Low temperatures may cause severe growth inhibition and mortality in fish. In order to understand the mechanism of cold tolerance, a transgenic zebrafish Tg (smyd1:m3ck) model was established to study the effect of energy homeostasis during cold stress. The muscle-specific promoter Smyd1 was used to express the carp muscle form III of creatine kinase (M3-CK), which maintained enzymatic activity at a relatively low temperature, in zebrafish skeletal muscle. In situ hybridization showed that M3-CK was expressed strongly in the skeletal muscle. When exposed to 13°C, Tg (smyd1:m3ck) fish maintained their swimming behavior, while the wild-type could not. Energy measurements showed that the concentration of ATP increased in Tg (smyd1:m3ck) versus wild-type fish at 28°C. After 2 h at 13°C, ATP concentrations were 2.16-fold higher in Tg (smyd1:m3ck) than in wild-type (P < 0.05). At 13°C, the ATP concentration in Tg (smyd1:m3ck) fish and wild-type fish was 63.3% and 20.0%, respectively, of that in wild-type fish at 28°C. Microarray analysis revealed differential expression of 1249 transcripts in Tg (smyd1:m3ck) versus wild-type fish under cold stress. Biological processes that were significantly overrepresented in this group included circadian rhythm, energy metabolism, lipid transport, and metabolism. These results are clues to understanding the mechanisms underlying temperature acclimation in fish.