PURPOSE. To study some functional candidate genes in cataract families of Indi an descent. METHODS. Nine Indian families, clinically documented to have congeni tal/childhood cataracts, were screened for mutations in c...PURPOSE. To study some functional candidate genes in cataract families of Indi an descent. METHODS. Nine Indian families, clinically documented to have congeni tal/childhood cataracts, were screened for mutations in candidate genes such as CRYG (A→D), CRYBB2, and GJA8 by PCR analyses and sequencing. Genomic DNA sample s of either probands or any representative affected member of each family were P CR amplified and sequenced commercially. Documentation of single nucleotide poly morphisms (SNPs) and candidate mutations was done through BLAST SEARCH(http://ww w.ncbi.nlm.nih.gov/ blast/Blast.- cgi?). RESULTS. Several single nucleotide polymorphisms in CRYG, CRYBB2, and G JA8 genes were observed. Because they do not co-segregate with the phenotype, t hey were excluded as candidates for the cataract formation in these patients. However, a substitution (W151C in exon 6 of CRYBB2) was identi fied as the most likely causative mutation underlying the phenotype of central n uclear cataract in all affected members of family C176. Protein structural inter pretations demonstrated that no major structural alterations could be predicted and that even the hydrogen bonds to the neighboring Leu166 were unchanged. Surpr isingly, hydropathy analysis of the mutant βB2-crystallin featuring the amino acids at position 147 to 155, further increased the hydrophobicity, which might impair the solubility of the mutant protein. Finally, the Cys residue at positio n 151 might possibly be involved in intramolecular disulphide bridges with other cysteines during translation, possibly leading to dramatic structural changes. CONCLUSIONS. Exon 6 of CRYBB2 appears to be a critical region susceptible for mu tations leading to lens opacity.展开更多
Non-invasive observation of spatiotemporal activity of large neural populations distributed over entire brains is a longstanding goal of neuroscience.We developed a volumetric multispectral optoacoustic tomography pla...Non-invasive observation of spatiotemporal activity of large neural populations distributed over entire brains is a longstanding goal of neuroscience.We developed a volumetric multispectral optoacoustic tomography platform for imaging neural activation deep in scattering brains.It can record 100 volumetric frames per second across scalable fields of view ranging between 50 and 1000 mm^(3) with respective spatial resolution of 35–200μm.Experiments performed in immobilized and freely swimming larvae and in adult zebrafish brains expressing the genetically encoded calcium indicator GCaMP5G demonstrate,for the first time,the fundamental ability to directly track neural dynamics using optoacoustics while overcoming the longstanding penetration barrier of optical imaging in scattering brains.The newly developed platform thus offers unprecedented capabilities for functional whole-brain observations of fast calcium dynamics;in combination with optoacoustics'well-established capacity for resolving vascular hemodynamics,it could open new vistas in the study of neural activity and neurovascular coupling in health and disease.展开更多
Neurons synthesizing the neurotransmitter dopamine exert crucial functions in the mammalian brain. The biggest and most important population of dopamine-synthesizing neurons is located in the mammalian ventral midbra...Neurons synthesizing the neurotransmitter dopamine exert crucial functions in the mammalian brain. The biggest and most important population of dopamine-synthesizing neurons is located in the mammalian ventral midbrain （VM）, and controls and modulates the exe- cution of motor, cognitive, affective, motivational, and rewarding behaviours. Degeneration of these neurons leads to motor deficits that are characteristic of Parkinson＇s disease, while their dysfunction is involved in the pathogenesis of psychiatric disorders including schizophrenia and addiction. Because the aetiology and therapeutic prospects for these diseases include neurodevelopmental aspects, substantial scientific interest has been focused on deciphering the mechanistic pathways that control the generation and sur- vival of these neurons during embryonic development. Researches during the last decade revealed the pivotal role of the secreted Wntl ligand and its signaUing cascade in the generation of the dopamine-synthesizing neurons in the mammalian VM. Here, we summarize the initial and more recent findings that have unravelled several Wntl-controUed genetic networks required for the proliferation and commitment of VM progenitors to the dopaminergic cell fate during midgestational embryonic stages, and for the correct differentiation of these progenitors into postmitotic dopamine-synthesizing neurons at late midgestational embryonic and foetal stages.展开更多
文摘PURPOSE. To study some functional candidate genes in cataract families of Indi an descent. METHODS. Nine Indian families, clinically documented to have congeni tal/childhood cataracts, were screened for mutations in candidate genes such as CRYG (A→D), CRYBB2, and GJA8 by PCR analyses and sequencing. Genomic DNA sample s of either probands or any representative affected member of each family were P CR amplified and sequenced commercially. Documentation of single nucleotide poly morphisms (SNPs) and candidate mutations was done through BLAST SEARCH(http://ww w.ncbi.nlm.nih.gov/ blast/Blast.- cgi?). RESULTS. Several single nucleotide polymorphisms in CRYG, CRYBB2, and G JA8 genes were observed. Because they do not co-segregate with the phenotype, t hey were excluded as candidates for the cataract formation in these patients. However, a substitution (W151C in exon 6 of CRYBB2) was identi fied as the most likely causative mutation underlying the phenotype of central n uclear cataract in all affected members of family C176. Protein structural inter pretations demonstrated that no major structural alterations could be predicted and that even the hydrogen bonds to the neighboring Leu166 were unchanged. Surpr isingly, hydropathy analysis of the mutant βB2-crystallin featuring the amino acids at position 147 to 155, further increased the hydrophobicity, which might impair the solubility of the mutant protein. Finally, the Cys residue at positio n 151 might possibly be involved in intramolecular disulphide bridges with other cysteines during translation, possibly leading to dramatic structural changes. CONCLUSIONS. Exon 6 of CRYBB2 appears to be a critical region susceptible for mu tations leading to lens opacity.
基金support from the European Research Council ERC-2010-StG-260991(DR)and ERC-2012-StG_20111109(AL and GGW)the National Institute of Health R21-EY026382-01(DR and SS)+1 种基金the German-Israeli Foundation(GIF)for Scientific Research and Development 1142-46.10/2011(DR and SS)the Helmholtz Association of German Research Centers and the Technische Universität München(DR and GGW)。
文摘Non-invasive observation of spatiotemporal activity of large neural populations distributed over entire brains is a longstanding goal of neuroscience.We developed a volumetric multispectral optoacoustic tomography platform for imaging neural activation deep in scattering brains.It can record 100 volumetric frames per second across scalable fields of view ranging between 50 and 1000 mm^(3) with respective spatial resolution of 35–200μm.Experiments performed in immobilized and freely swimming larvae and in adult zebrafish brains expressing the genetically encoded calcium indicator GCaMP5G demonstrate,for the first time,the fundamental ability to directly track neural dynamics using optoacoustics while overcoming the longstanding penetration barrier of optical imaging in scattering brains.The newly developed platform thus offers unprecedented capabilities for functional whole-brain observations of fast calcium dynamics;in combination with optoacoustics'well-established capacity for resolving vascular hemodynamics,it could open new vistas in the study of neural activity and neurovascular coupling in health and disease.
文摘Neurons synthesizing the neurotransmitter dopamine exert crucial functions in the mammalian brain. The biggest and most important population of dopamine-synthesizing neurons is located in the mammalian ventral midbrain （VM）, and controls and modulates the exe- cution of motor, cognitive, affective, motivational, and rewarding behaviours. Degeneration of these neurons leads to motor deficits that are characteristic of Parkinson＇s disease, while their dysfunction is involved in the pathogenesis of psychiatric disorders including schizophrenia and addiction. Because the aetiology and therapeutic prospects for these diseases include neurodevelopmental aspects, substantial scientific interest has been focused on deciphering the mechanistic pathways that control the generation and sur- vival of these neurons during embryonic development. Researches during the last decade revealed the pivotal role of the secreted Wntl ligand and its signaUing cascade in the generation of the dopamine-synthesizing neurons in the mammalian VM. Here, we summarize the initial and more recent findings that have unravelled several Wntl-controUed genetic networks required for the proliferation and commitment of VM progenitors to the dopaminergic cell fate during midgestational embryonic stages, and for the correct differentiation of these progenitors into postmitotic dopamine-synthesizing neurons at late midgestational embryonic and foetal stages.
