Project description:In mammals, retinal damage is followed by Müller glia cell activation and proliferation. While retinal gliosis persists in adult mammals after an insult or disease, some vertebrates, including zebrafish, have the capacity to regenerate. We believe we are the first group to show that gliosis is a fibrotic-like process in mammals’ eyes caused by differential activation of canonical and non-canonical TGFβ signaling pathways.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
Project description:Photoreceptor disorders are collectively known as retinal degeneration (RD), and include retinitis pigmentosa (RP), cone-rod dystrophy and age related macular degeneration (AMD). These disorders are largely genetic in origin; individual mutations in any one of >200 genes cause RD, making mutation specific therapies prohibitively expensive. A better treatment plan, particularly for late stage disease, may involve stem cell transplants into the photoreceptor or ganglion cell layers of the retina. Stem cells from young mouse retinas can be transplanted, and can form photoreceptors in adult retinas. These cells can be grown in tissue culture, but can no longer form photoreceptors. We have used microarrays to investigate differences in gene expression between cultured retinal progenitor cells (RPCs) that have lost photoreceptor potential, postnatal day 1 (pn1) retinas and the postnatal day 5 (pn5) retinas that contain transplantable photoreceptors. We have also compared FACS sorted Rho-eGFP expressing rod photoreceptors from pn5 retinas with Rho-eGFP negative cells from the same retinas. We have identified over 300 genes upregulated in rod photoreceptor development in multiple comparisons, 37 of which have been previously identified as causative of retinal disease when mutated. It is anticipated that this research should bring us closer to growing photoreceptors in culture and therefore better treatments for RD. This dataset is also a resource for those seeking to identify novel retinopathy genes in RD patients. We extracted whole retinas from postnatal day 1 (Pn1) and postnatal day 5 (Pn5) mice, and compared them with cultured RPCs derived from pn5 retinas, using Affymetrix mouse 430A_2 arrays. We also extracted cells from Rho-eGFP Pn5 retinas and FACS sorted them. GFP+ve cells represent immature rod photoreceptors, as they express the Rho-eGFP fusion protein, which is only expressed in rods. GFP-ve cells represent all other retinal neurons. These samples were amplified and compared using Affymetrix mouse 430A_2arrays, by Source Biosciences GMBH, Berlin, Germany. Results from immature rods were then compared with those from other retinal neurons, while results from whole Pn5 retinas were compared with Pn1 retinas (which don't yet express rod specific genes), and RPCs, which are glial precursors. RPCs were also compared with Pn1 retinas. Genes which showed changed expression profiles in at least 3/4 of comparisons were prioritised for further investigation.
Project description:Transcription profiling by array of mouse male retinas to investigate IGF-I-induced chronic gliosis and retinal stress IGF-I exert multiple effects in different retinal cell populations in both physiological and pathological conditions. Transgenic mice overexpressing IGF-I in the retina showed impaired electroretinographic responses at 6-7 months of age that worsen with age. This retinal neuronal dysfunction was correlated with the loss of rod photoreceptors, bipolar, ganglion and amacrines cells. Neuronal alterations were preceded by the overexpression of retinal stress markers, acute phase proteins and gliosis-related genes. IGF-I overexpression leads to chronic gliosis and microgliosis in TgIGF-I retinas, with mild oxidative stress, impaired recycling of glutamate and defective potassium buffering. These impaired supportive functions can contribute to neurodegeneration in TgIGF-I retinas, together with the increased production of pro-inflammatory cytokines, potential mediators of neuronal death.
Project description:Transcription profiling by array of mouse male retinas to investigate IGF-I-induced chronic gliosis and retinal stress IGF-I exert multiple effects in different retinal cell populations in both physiological and pathological conditions. Transgenic mice overexpressing IGF-I in the retina showed impaired electroretinographic responses at 6-7 months of age that worsen with age. This retinal neuronal dysfunction was correlated with the loss of rod photoreceptors, bipolar, ganglion and amacrines cells. Neuronal alterations were preceded by the overexpression of retinal stress markers, acute phase proteins and gliosis-related genes. IGF-I overexpression leads to chronic gliosis and microgliosis in TgIGF-I retinas, with mild oxidative stress, impaired recycling of glutamate and defective potassium buffering. These impaired supportive functions can contribute to neurodegeneration in TgIGF-I retinas, together with the increased production of pro-inflammatory cytokines, potential mediators of neuronal death. 3 transgenic and 3 wild type biological replicates examined.
Project description:Control CAG-GFP or CAG-Zfp292 (Zfp292-OE) plasmids were electroporated into P0 mouse pups in vivo. We harvested the retinas 4 days later to allow for robust expression, dissociated the retinas into single cell preps, collected the GFP+ Retinal progenitor cells (RPCs) via FACS sorting from control or Zfp292-OE conditions, and processed the cells for bulk RNA-seq.